EPA-AA-TSS-91-1
The IM240 Transient I/M Dynamometer Driving Schedule
        and The Composite I/M Test Procedure
                William M. Pidgeon

                   Natalie Dobie
                   January 1991
               Technical Support Staff
        Emission Control Technology Division
              Office of Mobile Sources
          Environmental Protection Agency

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                      Table  of Contents


1.0  Introduction	1

2 . 0  Background	1

3.0  The Problem	2

4.0  Old Technology versus New Technology	3

5.0  IM240 versus CDH-226	3

6.0  IM240 Description	6

7.0  Composite I/M Test Procedure	7

      7 .1  Dynamometer Settings	7

      7 .2  Sampling Methods	9

      7 .3  CITP Steady-State Modes	10

8 .0 Summary	10

Appendix 1
      IM240 Speed Versus Time Table	A-l

Appendix 2
      Comparative Statistics	A-6

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1. 0    Introduction

      The United States Environmental Protection Agency (EPA)  is
evaluating new test procedures for use as Inspection/Maintenance C/M)
tests.  Two tests under consideration are the IM240,  a new driving
schedule developed by the U.S. EPA, and the CDH-226,  a driving schedule
developed earlier by the Colorado Department of Health.  EPA's focus on
these procedures as possible alternatives to current I/M tests has
aroused interest.  The purpose of this document is to provide
descriptive information about these tests to the I/M community.
Statistical results from the first year of testing on the IM240 and the
CDH-226 will be published later.

      This document also provides information on EPA's Composite I/M
Test Procedure  (CITP),  a lengthy testing sequence designed to evaluate
the effectiveness of a large number of potential alternative I/M tests,
including the IM240 and the CDH-226.

      The IM240 and CDH-226 driving schedules are both based on EPA's
Federal Test Procedure (FTP), which certifies compliance with federal
vehicle emission standards for carbon monoxide  (CO),  unburned
hydrocarbons  (HC), and nitrogen oxides (NOx).  Since a significant
portion of the I/M community is relatively unfamiliar with certification
procedures, the following section provides the basic background needed
to understand the foundations of the IM240 and the CDH-226.

2.0    Background

      In order for vehicle emissions to be controlled effectively,  they
must be evaluated under real world conditions.  With this in mind, the
United States has designed it's vehicle emission control strategy around
tests that measure emissions while replicating actual driving
conditions.  These tests stem from the development in  1965 of the LA-4
road route, which was designed to approximate a typical morning trip to
work in rush-hour traffic in Los Angeles.1  In 1972,  the EPA shortened
the LA-4 from 12 to 7.5 miles and adapted it for use in the laboratory
on a chassis dynamometer, a device that simulates vehicle load and
inertia weight.2  Since known as the Urban Dynamometer Driving Schedule
 (UDDS), it is the driving schedule used to conduct the FTP.
1 Mass, G. C., Sweeney, M. P., and Pattison,  J.  N.,  "Laboratory
Simulation of Driving Conditions in the Los Angeles Area," SAE Paper No.
660546, August 1966.

2 Kruse, R. E. and Huls, X. A., "Development  of  the Federal Urban
Driving Schedule," SAE Paper No. 730553, May 1973.

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      The FTP is the "golden standard" for determining vehicle emission
levels,  but it is expensive and time consuming.  The EPA has approved
six shorter tests for use by I/M programs in their evaluation of ir.-use
vehicle emissions.  All six currently approved I/M tests are steady-
state (one-speed) tests.  Five are unloaded, and one is loaded.  These
tests are described in the Code of Federal Regulations, Title 40, Part
81, Sections 2209 - 2214.  Considerably less resource intensive than the
FTP, short tests were designed to provide a more easily used but still
reliable method of identifying vehicles that exceed FTP standards.

3.0   The Problem

      The short I/M tests do not always correlate well to the FTP,
however.  Limitations in the tests themselves and, perhaps more
importantly,  changes in vehicle design have undermined the ability of
current short tests to identify a vehicle's excess emissions (i.e.,
emissions above the federal standards).  I/M tests originally were
designed for a vehicle fleet that is rapidly being displaced by new
technology, computer-controlled vehicles.  New technology vehicles are
equipped with improved emission control components, such as three-way
catalysts, closed-loop fuel control, and fuel injection, which have
changed the way vehicles respond to emission tests.3

      These changes have implications for the future effectiveness of
I/M programs.  The effectiveness of short emission tests can be
expressed in terms of overall failure rate, excess emissions identified
(identification rate), errors of commission, and errors of omission.
Errors of commission  (Ec), or false failures, occur when vehicles fail
an I/M test but pass the FTP.  Errors of omission  (Eo), or false passes,
occur when vehicles pass the I/M test but fail the FTP.  Based on these
measures, EPA studies indicate that current short tests have become .less
effective in identifying excess emissions since the introduction of new
technology vehicles in 1981.  The challenge now is to ensure that I/M
tests keep pace with changing technology so that they remain an
effective tool for vehicle emission control.
3 Armstrong,  J.,  Brzezinski, D. J., Landman,  L.,  and Glover,  E.  L.,
"Inspection/Maintenance in the 1990's," SAE Paper No. 870621,  February
1987.

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4 .0    Old  Technology  versus  New Technology

      Old technology, pre-computer-controlled vehicles have emission-
related components that operate on  a continuum.  For example, if the
air-fuel mixture at idle is too rich, then the air-fuel mixture is
likely to be too rich across much of the operating range of the vehicle
(i.e., cruise, acceleration, deceleration).  For this reason a test
performed only at idle or only at 30 mph is likely to identify pre-
computer-controlled vehicles that malfunction to a sufficient degree to
fail the FTP test also.  This continuum characteristic is an inherent
feature of many mechanically controlled systems, including other
emission-control components like the ignition system's distributor,
which controls the ignition timing.

      The newer, computer-controlled vehicles that are becoming an ever
larger fraction of the fleet are not constrained by the continuum
characteristic of mechanical devices.  A computer can include discrete
instructions for the air-fuel mixture at idle that have little bearing
on the mixture at 30 mph or during  an acceleration from 10 mph to 20
mph.  For this reason, a vehicle with low emissions at idle or 2500 rpm
or 30 mph can in principal have unacceptably high emissions during other
modes.  Furthermore, EPA studies show that some vehicles with very high
FTP emissions do indeed pass a steady-state test, such as an idle test.
By the same logic, a vehicle with high idle emissions may pass the FTP
because the emissions are low through most of the vehicle's other
operating modes.  An idle test falsely fails such vehicles.  Transient
tests, on the other hand, are responsive to changing emission levels
during different modes of vehicle operation and thus overcome the
limitations of steady-state testing on computer-controlled vehicles.

5.0    ZM240  versus  CDH-226

      In the face of changing technology,  EPA's objective was to find a
short transient test that would identify high emitting vehicles as
defined by their FTP emissions,  while minimizing errors of commission.
Initially, the CDH-2264 seemed to offer the best possibility for a
viable I/M test.  Since then,  EPA has developed the IM240 as a possible
improvement on the CDH-226.
4 Ragazzi,  R.  A.,  Stokes,  J. T.,  and Gallagher,  G.  L.,  "An  Evaluation  of
a Colorado Short Vehicle Emission Test (CDH-226) in Predicting Federal
Test Procedure (FTP) Failures," SAE Paper No.  852111,  October 1985.

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      A characteristic of the CDH-226 that stands out when compared to
Che UDDS is that the CDH-226 is smoother  (i.e., less transient), so it
requires less throttle action  (see Figure 1 en page 5).   Throttle action
is an important variable affecting vehicle emissions and could be
important in identifying malfunctioning vehicles.

      Take oxygen sensor operation as an example.  As oxygen sensors
deteriorate, their response time  lags.  This deteriorating response time
can allow the air-fuel mixture to increasingly deviate from
stoichiometric  (14.7:1), the ratio at which 3-way catalysts most
efficiently oxidize HC and CO and simultaneously reduce NOx  (see Figure
2 below).  This is important because three-way catalyst conversion
efficiency rapidly deteriorates with air-fuel mixture deviations from
stoichiometric.  During steady-state operation, the fuel metering system
adjusts to deliver a stoichiometric mixture, which should stay
relatively constant.  Throttle movement cften causes the mixture to
change, and as throttle action increases, che ability of the metering
system to maintain stoichiometry becomes increasingly dependent on the
response time of the oxygen sensor.  A highly transient driving schedule
requires more throttle action than a smooth schedule, so a deteriorated
oxygen sensor is more likely to be identified on a highly transient
schedule than on a smooth schedule.  The same logic can also be extended
to other components of emission control systems.  A driving schedule can
be made too transient, however.  An I/M test requiring more throttle
action than the UDDS might unacceptably increase test variability and
thereby increase the error of commission rate.

      Figuza  2:    Air-Fuel   Ratios  and  Conversion  Efficiency
                       100-
                    *  9S-
                    "O 90-
                    -«
                    ys
                    *2 s
                    «c
                    «   .
                    1870H
                     *
                                  14.4 14.7 15.0
                                  AIR/FUEL RATIO*
                                BICH •  |    • «.6AN

      •Converted from equivalence ratios used in the original.

      Source:  Rivard, J. G., "Closed-Loop Electronic Fuel Injection
      Control of the Internal Combustion Engine," SAE Paper No. 730005,
      January 1973, p. 4.

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                 Figure 1: Comparison of Dynamometer Driving Schedules
                                    CDH-226 Driving Schedule
(mph)
      50-
      40-
      30-
      20
      10-
       0
         0
                    50          100         150         200         250         300
                                             Time
                         Hills 1 & 2 of the Urban Dynamometer Driving Schedule
(mph)
      50-
      40-
      30
      20-
      10-
       0
                    50          100         150         200         250         300
                                             Time
                                      IM240 Driving Schedule
      50
      40-
Speed  30.
(mph)
      20-
      10-
       0
                   50         100        150        200        250        300
                                             Time

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      For these reasons, EPA decided to develop a more transient
alternative to the CDH-226, to make the new test similar to the HDDS,
and to evaluate both procedures to determine which is better for I/.M
testing.  EPA's alternative was dubbed the IM240 since it was designed
for I/M testing with a duration of 240 seconds.

6.0    IM240  Description

      The IM240 driving schedule is depicted graphically in Figure i.
Appendix 1 provides a speed-versus-ti.-ne table in one-second increments.
The table also lists the UDDS segments that were used to create the
IM240.

      The IM240 was patterned closely on the first two "hills" of the
UDDS.  It uses actual segments of the UDDS and incorporates the UDDS's
peak speed of 56.7 miles per hour.  Testing over the entire range of
speeds was considered important to detect malfunctioning vehicles given
the discontinuous operating characteristics of computer-controlled
vehicles.  Using actual segments of the UDDS was considered important to
help improve correlation and minimize errors of commission and errors of
omission.

      The two large decelerations from hills 1 and 2 are the only
segments that were not taken directly from the UDDS.  The deceleration
rate for both hills was set at 3.5 mph/sec, whereas the maximum
deceleration rate from the UDDS is 3.3 mph/sec.  The higher deceleration
rate prevents the IM240 from exceeding four minutes, which was taken
somewhat arbitrarily to be a measurable upper limit for a test time that
would allow an adequate rate of vehicle processing, or throughput.   The
3.5 mph/sec rate, which has been used successfully in the CDH-226,  also
allows time for an idle and an additional transient portion on hill 2
(between 140 seconds and 158 seconds).

      As seen in Appendix 2, the IM240 differs statistically from the
CDH-226.  Because of differences in design, it was speculated that  one
of the tests might correlate better than the other to the FTP.

      The IM240 test is run in two segments.  The shorter segment is 94
seconds in duration, which was an informed guess as to the minimum
amount of time needed to realize significant improvements in FTP
correlation.  For comparison, EPA has divided the CDH-226 into  two
segments as well, the shorter segment being 86 seconds.   By dividing
each test into two parts,  EPA can evaluate the effectiveness of the
entire test as well as the effectiveness of each of the shorter
segments.

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      The test procedure stipulates tr.at the engine is running with the
transmission in gear before the driving schedule begins.   Ixhaust
sampling begins simultaneously with the start cf the driving scneduie.

      IM240 testing is being performed separately and in conjunction
with other short tests, including the C2H-226, in the Composite ;,M Test
Procedure, which is described below.

7.0    Composite  I/M  Test  Procedure

      The EPA has devised the multi-purpose Composite I/M Test Procedure
(CITP) -.0 evaluate the effectiveness of the IM240, the CDH-226, and
potential steady-state alternatives to current I/M tests.  The goal of
the program is to identify emission tests wnich balance the need for
high FTP correlation and high identification rates against cost,
equipment, and time requirements.  Acceptable alternative tests would be
sopnisticated enougn to measure the emissions of r.ew cecnnoiogy
venicies adequately while conforming to the constraints of an I/M
program.

      CITP testing is being performed at EPA's Motor Vehicle Emission
Laboratory  (MVEL) in Ann Arbor, Michigan and under contract at the
Automotive Testing Laboratories  (ATL) facility in New Carlisle, Indiana,
just outside of South Bend.  All Emission Factor Program- test vehicles
receive the CITP after the as-received FTP test on Indolene test fuel.

      7.1    Dynamometer  Settings

      The CITP sequence consists of 11 test modes run over 77 minutes.
At EPA's lab, the CITP is divided into two parts, A and B, which differ
by the dynamometer settings used (see Table 1).   (Because of different
equipment configurations, testing at the ATL facility is done in four
pares.)  Pare A is performed using the certification dynamometer
settings, which require an expensive multiple curve dynamometer and a
complicated process for determining the proper road load and inertia
weight settings for each vehicle.  In Part B,  the dynamometer settings
are limited in order to evaluate the tradeoff between cost and FTP
correlation that is associated with less sophisticated dynamometers.
5 The Emission Factor Program tests vehicles owned by the general
public.  Data from these in-use vehicles are used with a computer  model
known as MOBILE4 to calculate the emission rates of in-use vehicles.
These emission rates are then used with air quality models to estimate
the contribution of mobile source emissions to ambient air pollution.

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Modes of the Composite I/M Test Procedure
for use with Emission factors Vehicles
SEGMENT
NO NAME
1
2
3
4
5
•
6
7
8

9
10
11

IM240 (2x)
IM240
S3 Series
IM240
CDH226
TECH BREAK
SS50
COH226
2-Mode Idle
Restart
TECH BREAK
SS50
IM240
SS Series

MODE
IH240
IM240
IM240
20 mph
Idle-N
30 mph
Idle-N
40 mph
Idle-N
50 mph
Idle-N
IM240
CDH226

50 mph '
COH226
Idle-N
2500 rpm
Idle M
Eng. off
2500 rpm
Idle-N

50 mph
IH240
20 mph
Idle-N
30 mph
Idle-N
40 mph
Idle-N
50 mph
Idlc-N

TYPE
Trans
Trans
Stdy St
••
t*
M
M
•«
M
Trana
Trans
N/A
Stdy St
Trans
Stdy St
(•
M
«l
N/A
Stdy St
Trans
Stdy St
it
••
M
M
M
••
TOTAL

Loaded
M
Loaded
Loaded
Unloaded
Loaded
Unloaded
Loaded
Unloaded
Loaded
Unloaded
Loaded
Loaded

Loaded
Loaded
Unloaded
1*
ti
M
•I

Loaded
Loaded
Loaded
Unloaded
Loaded
Unloaded
Loaded
Unloaded
Loaded
Unloaded

DYNO
Cert
Cert
Cert
M
M
Cert
Cert

2-IH
2-IH
N/A
M

2-IH
2-IH
Trim
M
• •
••

MODE CUM
PAU SAMP DOR DOR
Cert Raw
Cert CVS+Raw
Cert Raw
M II
I* M
M M
*f M
M M
Cert Raw
Cert CVS » Raw

Cert Raw
Cert CVS+Raw
N/A Raw
M ••
t* ••
• t «•
•• M

Cert Raw
Cert CVS t Raw
Clay Raw
•I M
*• M
It M *
»• »•
*• M
1* M

4
4
4
2
1
2
1
2
1
2
1
4
4
10
3
4
0.5
0.5
1
0.2
0.5
1
5
3
4
2
1
2
1
2
1
2
1
77
4
a
12
14
15
17
18
20
21
23
24
28
32

3
7
8
8
9
9
10
11

3
7
9
10
12
13
15
16
18
19

NOTES
1. Clayton loading is 30IIP Q 50mph (cubic curve)
2. 50 mph cruise at Clayton loadings may be dropped for small vehicles
3. 2-IW requires IH settings of 2500 or 3500. depending on vehicle
4. Oyno settings will need to be changed prior to steps 6 and 11
NOTES
Harmup; compare raw vs CVS sampling
Hiqh throttle action transient
Compare var-PAU/f ixed-apd ( var-PAU/var-spd
Modes: 20/ I /30/1 /40/I/50/ I 62 min/cruiae.l min/I
Harmup
Moderate throttle action transient

Harmup
Compare cert IH to simple IH approach
Conventional I/M

Harmup
Compare cert IH to simple IH approach
Compare Clayton aingle-curve to cert curves

van 2.21-
11/16/89

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The dynamometer settings in Part 3 are li.-rj.teci to two possible inertia
weight settings of 2500 or 3500 pounds, ciepenaing en the weight of the
vehicle.   Steady-state loaded modes  ;..-. Part 3 are performed with cnly a
single setting  (30 hp @ 50 mph) for  ail venicies to simulate the Clayton
single-curve dynamometers.  A yet-to-De-ccmpieted comparison of test
results between carts A and 3 will help co determine whether the expense
of certification-type dynamometers is  justified.

      7.2    Sampling  Methods

      The CITP also allows EPA to compare methods of measuring exhaust
emissions.  The entire CIT? series undergoes second-by-second raw
exhaust measurements.  MVEL uses an  Allen 3AR-80 specification analyzer
-o gather and analyze the sample and a Macintosh running EPA's GAS-4
program for data collection.  ATL uses a Gordon-Darby analyzer to
i.naiyze the sample ana an IBM-compatible computer for data collection.

      In addition to raw exnaust measurements, which reveal the
concentration of pollutants  (percentage or parts per million), loaded
transient modes also are analyzed using Constant Volume Sampling (CVS),
which reveals mass emissions  (grams  per mile).  Raw exhaust
measurements, while less complicated and less expensive than CVS, do not
account for differences in the size  of the exhaust stream and so do not
accurately measure the total mass of pollutants emitted.6   Constant
Volume Sampling, on the other hand,  does measure the mass of pollutants
but requires complicated and expensive equipment.  If certain
assumptions are made, mathematical formulas can be applied to raw
exhaust measurements so that they can  be expressed as approximate mass
measurements.   3y comparing the results of these calculations to the
actual CVS readings, the accuracy of the calculated mass results can be
5 CVS measurements provide a much better indication of vehicle emission
levels than raw exhaust measurements.  A raw exhaust reading of 200 ppm
HC from a small motorcycle and the same 200 ppm reading from a large
truck  (which is entirely possible) suggest that the two vehicles pollute
equally.  However, such a conclusion is wrong.  The truck will have a
much higher volume of exhaust.  Over a given one-mile drive, the
motorcycle may only emit 50 cubic feet of exhaust gases, whereas the
truck may emit 500 cubic feet,  with both vehicles emitting 200 ppm HC
over the mile, the total amount of HC emitted by the truck will be 10
times greater than the amount emitted by the motorcycle.  A Constant
Volume Sampler allows the total emissions per mile to be measured; a raw
exhaust analyzer does not.

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determined.  If the identification rates, errors of commission, and
errors of omission from the raw exhaust calculations compare favorably
zo the CVS readings, use of the less expensive, less complicated raw
exhaust method may be justified.

      7.3   CITP  Steady-State  Modes

      In addition to the IM240 and the CDH-226, the CITP includes a
loaded steady-state test at 50 mpn  (SSSO) , a two-mode idle restart test,
and a steady-state series.  The steady-state test at 50 mph is run for
three minutes as a warm-up for the IM240 and the CDH-226.  The two-mode
idle segment is approximately four minutes in duration.  This test
consists of an engine restart inserted between sequences of idle and
2500 rpm operation.  The two-mode idle was included in the CITP because
it is representative of tests currently being used in many I/M programs.

      The steady state series contains .oaaed modes at 20, 20, -iO,  and
30 mph separated by an idle.  This series represents an intermediate
step between the idle test and the loaded transient schedule.  Its
advantages over loaded transient cycles include the cost savings of raw
gas versus CVS analyzers and of single versus multiple curve
dynamometers.  In addition, unlike loaded transient cycles, the steady-
state series does not require the use of driving schedules or related
equipment or technician skills.7

8. 0  Summary

      Changes in vehicle technology have created the need for more
sophisticated I/M tests.   In response  to this need, the EPA has
developed the IM240, a short transient test, as a possible alternative
to current I/M tests.  The EPA is evaluating the IM240 as well as the
CDH-226 and several steady-state tests in the Composite I/M Test
Procedure.  CITP testing is ongoing, and the results will be published
at a later date.
7 McCargar, J., Memorandum to Richard D. Lawrence,  October 19,  1989,
U.S. EPA, Emission Control Technology Division, Technical Support Staff.
                                      10

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                 Appendix  1

            IM240 Soeeci versus Tine Table
UDDS
Equiv Tir.e
sees .
16
17
18
19
20
21
22
23
24
25
26
27
23
2 3
20
31
22
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
IM240
Speed
mph
0
0
0
0
0
3
5.9
3.6
11.5
14.3
16.9
17.3
13 1
2D.7
2 1 7
22.4
22.5
22.1
21.5
20.9
20.4
19.8
17
14.9
14.9
15.2
15.5
16
17.1
19.1
21.1
22.7
22.9
22.7
22.6
21.3
19
17.1
15.8
15.8
17.7
19.8
21.6
23.2
24.2
24.6
24.9
25
IM240
Accel Rate
r.ph/sec

0
0
0
0
3
2.9
2.7
2.9
2.8
2.6
0.4
0.3
2 . 6
^
0.7
0.1
-0.4
-0.6
-0.6
-0.5
-0.6
-2.8
-2.1
0
0.3
0.3
0.5
1.1
2
2
1.6
0.2
-0.2
-0.1
-1.3
-2.3
-1.9
-1.3
0
1.9
2.1
1.8
1.6
1
0.4
0.3
0.1
Actual Time
   sees.
     3
     4
     5
     5
     7
     3
     9
     10
     11
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45
     46
     47

•Engine  is running and transmission is in gear before
 driving schedule and exhaust sampling begin.

                         A-l

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Actual Time
sacs .
48
49
50
51
52
53
54
55
56
57
53
59
60
61
62
63
64
55
66
67
63
69
70
71
72
73
74
75
76
77
78
79
30
81
32
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
UDDS
£quiv Time
sees .
30
81
32
83
84
95
36
37
38
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116












163
164
165
IM240
Speed
mph
25.7
26.1
26.7
27.5
28.6
29.3
29.8
30.1
30.4
30.7
30.7
30.5
30.4
30.3
30.4
30.'8
jO.4
29.9
29.5
29.8
30.3
30.7
30.9
31
30.9
30.4
29.8
29.9
30.2
30.7
31.2
31.8
32.2
32.4
32.2
31.7
28.6
25.1
21.6
18.1
14.6
11.1
7.6
4.1
0.6
0
0
0
0
0
3.3
6.6
                IM240
             Accel Rate
              .Tvph/sec

                 0.7
                 0.4
                 0.6
                 0.8
                 1.1
                 0.7
                 0.5
                 0.3
                 0.3
                 0.3
                  0
                -0.2
                -0.1
                -0.1
                 0.1
                 0.4
                -0.4
                -0.5
                -0.4
                 0.3
                 0.5
                 0.4
                 0.2
                 0.1
                -0.1
                -0.5
                -0.6
                 0.1
                 0.3
                 0.5
                 0.5
                 0.6
                 0.4
                 0.2
                -0.2
                -0.5
                -3.1
                -3.5
                -3.5
                -3.5
                -3.5
                -3.5
                -3.5
                -3.5
                -3.5
                -0.6
                  0         Bag  2
                  0
                  0
                  0
                 3.3
                 3.3
A-2

-------

Actual Time
sees .
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
UDDS
Equiv Time
sees .
166
167
168
169
170
171
172
173
174
175
176
178
179
181
182
183
184
135
186
187
188
189
190
29
30
31
32
33
34
35
36
37
38
53
54
55
56
57
58
191
192
66
67
68
69
70
71
72
73
74
75
76
IM240
Speed
mph
9.9
13.2
16.5
19.8
22.2
24.3
25.8
26.4
25.7
25.1
24.7
25.2
25.4
27.2
26.5
24
22.7
19.4
17.7
17.2
18.1
18.6
20
20.7
21.7
22.4
22.5
22.1
21.5
20.9
20.4
19.8
17
17.1
15.8
15.8
17.7
19.8
21.6
22.2
24.5
24.7
24.8
24.7
24.6
24.6
25.1
25.6
25.7
25.4
24.9
25
IM240
Accel Race
mph/sec
3.3
3.3
3.3
3.3
2.4
2.1
1.5
0.6
-0.7
-0.6
-0.4
0.5
0.2
1.8
-0.7
-2.5
-1.3
-3.3
-1.7
-0.5
0.9
0.5
1.4
0.7
1
0.7
0.1
-0.4
-0.6
-0.6
-0.5
-0.6
-2.8
0.1
-1.3
0
1.9
2.1
1.8
0.6
2.3
0.2
0.1
-0.1
-0.1
0
0.5
0.5
0.1
-0.3
-0.5
0.1
A-3

-------

Actual Time
sees .
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
UDDS
Equiv Ti.T.e
sees .
77
78
79
30
81
3->
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
209
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241


IM240
Speed
mph
25.4
26
26
25.7
26.1
^5.7
27.3
30.5
33.5
36.2
37.3
39.3
40.5
42.1
43.5
45.1
•46
46.3
47.5
47.5
47.3
47.2
47.2
47.4
47.9
48.5
49.1
49.5
50
50.6
51
51.5
52.2
53.2
54.1
54.6
54.9
55
54.9
54.6
54.6
54.8
55.1
55.5
55.7
56.1
56.3
56.6
56.7
56.7
56.3
56
IM240
Accel Rate
mph /sec
0.4
0.6
0
-0.3
0.4
0.6
0.6
3.2
3
2.7
1.1
2
1.2
1.6
1.4
1.6
0.9
0.8
0.7
0
-0.2
-0.1
0
0.2
0.5
0.6
0.6
0.4
0.5
0.6
0.4
0.5
0.7
1
0.9
0.5
0.3
0.1
-0.1
-0.3
0
0.2
0.3
0.4
0.2
0.4
0.2
0.3
0.1
0
-0.4
-0.3
A-4

-------

Actual Time
sees .
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
UDDS
Equiv Time
sees .


271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
















IM240
Speed
mph
55
53.4
51.6
51.8
52.1
52.5
53
53.5
54
54.9
55.4
55.6
56
56
55.8
55.2
54.5
53.6
52.5
51.5
50.5
48
44.5
41
37.5
34
30.5
27
23.5
20
16.5
13
9.5
6
2.5
0
IM240
Accel Rate
mph /sec
-1
-1.6
-1.8
0.2
0.3
0.4
0.5
0.5
0.5
0.9
0.5
0.2
0.4
0
-0.2
-0.6
-0.7
-0.9
-1.1
-1
-1
-2.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-3.5
-2.5
A-5

-------
Actual :
   sees

    204
    205
i-.e
iquiv Ti.-e
  sees.
                              IM240
                                 . 4
 IM240
eel ?.a-e
r.p.-./sec
                                33
    212
    213
    214
    215
    216
    217
    213
    219
    223
    224
    225
    226
    127
    223
    229
    230
    231
    232
    233
    234
    235
    236
    237
    233
    239
<.
-)
<.

: •
50.
48
44.
41
37.
34
30.
27
23.
20
16 .
13
5

9
4
5


3
2
5
5
^
^
5

5

5

5

5

5

9.5


6

2.5


0

-\
•j .
0.
,-\
V .
A
U .
0.
0.
0
-0.
-0.
-0.
-0.
- ;_ _
_ 1
-1
-2.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-3.
-2.
5
5
9
5
2
4

-i
4.
6
7
9
7_


5
5
5
5
3
5
5
5
5
5
5
5
5
5
5
                        A-5

-------
                                   Acoendix 2
                            Corr.paraci
                                    "
                                     Idle Hades
 IM240
             i u me s •  c r
           idle Periods
               (sec)
               .3.0
                3.0
               Percent  of   Length  :f
                 Total      First  Idle
               Schedule      (sec)
                 3.3
                 .9.0
                 .9.9
               4.0
              20.0
              Average
             Idle Time
                (sec)

               4.5
              14.4
              15.0
               Standard
               Deviation
               Idle Time

                   C.7
                  10.7
                  12.3
  I.M240
  C2H-225
           race Speed
           t.T.ph)
            30.0
            19.5
            22.3
                 Speeds

              Average Speed
                ' Without
               Idle Modes
                  (.T.ph)
                  30.8
                  24.1
                  27.9
                  Maximum Speed
                     (mph)
                      56.7
                      56.7
                      51.3
IM240
•JDOS
CDH-226
0-10 mph

   5.2
  13.8
   9.4
                                10  mph  Segments

                     '.r  ;f Drivir.y Schedule  in  gaeh  10  rr.ph
                            (without idle modes)

                     .0-20 moh    20-30  moh   30-40 mch
18.3
19.2
12.7
34.3
45.9
46.4
13.9
11.0
 8.3
40-50 mph

 8.7
 3.4
19.9
SQ-SQ moh

19.1
 6.6
 3.3
                   Average Rate  of  Acgeleration  fm
IM240
uDDS
CDH-226
0 - 1 0 mph
3.1
2.3
2.3
10-20 mph
1.6
1.8
2.0
20-30 mph
0.83
0.72
0.74
30-40 mph
0.86
0.67
1.4
40-50 mph
0.85
0.80
0.53
SO-SO m=h
0.43
0.38
0.57
                   Average Rate of  Deceleration  fm
IM240
UDDS
CDH-226
0 - i 0 mph
3.5
2.4
2.0
10-20 mph
2.3
2.1
1.7
20-30 mph
1.1
0.81
0.70
30-40 mph
1.2
0.54
1.4
40-50 mph
2.0
0.61
0.61
SO-SO mph
0.79
0.42
0.40
                                      A-6

-------
                                            EPA-AA-TSS-91-1
The IM240 Transient I/M Dynamometer Driving Schedule
        and The Composite I/M Test Procedure
                William M. Pidgeon

                   Natalie Dobie
                   January 1991
               Technical Support Staff
        Emission Control Technology Division
              Office of Mobile Sources
          Environmental Protection Agency

-------
                                            "EPA-AA-TSS-91-1
The IM240 Transient I/M Dynamometer Driving Schedule
        and The Composite I/M Test'Procedure
                William M. Pidgeon

                   Natalie Dobie
                   January 1991
               Technical Support Staff
        Emission Control Technology Division
              Office of Mobile Sources
          Environmental Protection Agency

-------
                     Table of Contents


1. 0  Introduction	1

2 .0  Background	1

3.0  The Problem	2

4 . 0  Old Technology versus New Technology	3

5.0  IM240 versus CDH-226	3

6.0  IM240 Description	6

7.0  Composite I/M Test Procedure.	7

      7 .1  Dynamometer Settings	7

      7.2  Sampling Methods	9

      7.3  CITP Steady-State Modes	10

8.0 Summary	10

Appendix 1
      IM240 Speed Versus Time Table	A-l

Appendix 2
      Comparative Statistics	A-6

-------
1.0    Introduction

      The United States Environmental Protection Agency (EPA)  is
evaluating new test procedures for use as Inspection/Maintenance (I/M)
tests.  Two tests under consideration are the IM240, a new driving
schedule developed by the U.S. EPA, and the CDH-226, a driving schedule
developed earlier by the Colorado Department of Health.  EPA's focus on
these procedures as possible alternatives to current I/M tests has
aroused interest.  The purpose of this document is to provide
descriptive information about these tests to the I/M community.
Statistical results from the first year of testing on the IM240 and the
CDH-226 will be published later.

      This document also provides information on EPA's Composite I/M
Test Procedure (CITP), a lengthy testing sequence designed to evaluate
the effectiveness of a large number of potential alternative I/M tests,
including the IM240 and the CDH-226.

      The IM240 and CDH-226 driving schedules are both based on EPA's
Federal Test Procedure (FTP), which certifies compliance with federal
vehicle emission standards for carbon monoxide  (CO), unburned
hydrocarbons (HC), and nitrogen oxides (NOx).  Since a significant
portion of the I/M community is relatively unfamiliar with certification
procedures, the following section provides the basic background needed
to understand the foundations of the IM240 and the CDH-226.

2.0    Background

      In order for vehicle emissions to be controlled effectively,  they
must be evaluated under real world conditions.  With this in mind, the
United States has designed its vehicle emission control strategy around
tests that measure emissions while replicating actual driving
conditions.  These tests stem from the development in  1965 of  the LA-4
road route, which was designed to approximate a typical morning trip to
work in rush-hour traffic in Los Angeles.1  In 1972,  the EPA shortened
the LA-4 from 12 to 7.5 miles and adapted it for use in the laboratory
on a chassis dynamometer, a device that simulates vehicle load and
inertia weight.2  Since known as the Urban Dynamometer Driving Schedule
(UDDS), it is the driving schedule used to conduct the FTP.
1 Hass,  G.  C.,  Sweeney,  M.  P.,  and Pattison,  J.  N.,  "Laboratory
Simulation of Driving Conditions in the Los Angeles Area," SAE Paper No
660546,  August 1966.

2 Kruse, R. E.  and Huls, T. A.,  "Development  of  the Federal Urban
Driving Schedule," SAE Paper No. 730553, May 1973.

-------
      The FTP is the "golden standard" for determining vehicle emission
levels, but it is expensive and time consuming.  The EPA has approved
six shorter tests for use by I/M programs in their evaluation of in-use
vehicle emissions.  All six currently approved I/M tests are steady-
state  (one-speed) tests.  Five are unloaded, and one is loaded.  These
tests are described in the Code of Federal Regulations, Title 40, Part
81, Sections 2209 - 2214.  Considerably less resource intensive than the
FTP, short tests were designed to provide a more easily used but still
reliable method of identifying vehicles that exceed FTP standards.

3 . 0    The Problem

      The short I/M tests do not always correlate well to the FTP,
however.  Limitations in the tests themselves and, perhaps more
importantly, changes in vehicle design have undermined the ability of
current short tests to identify a vehicle's excess emissions (i.e.,
emissions above the federal standards).  I/M tests originally were
designed for a vehicle fleet that is rapidly being displaced by new
technology, computer-controlled vehicles.  New technology vehicles are
equipped with improved emission control components, such as three-way
catalysts, closed-loop fuel control, and fuel injection, which have
changed the way vehicles respond to emission tests.3

      These changes have implications for the future effectiveness of
I/M programs.  The effectiveness of short emission tests can be
expressed in terms of overall failure rate, excess emissions identified
(identification rate), errors of commission, and errors of omission.
Errors of commission  (Ec), or false failures, occur when vehicles fail
an I/M test but pass the FTP.  Errors of omission  (Eo), or false passes,
occur when vehicles pass the I/M test but fail the FTP.  Based on these
measures, EPA studies indicate that current short tests have become less
effective in identifying excess emissions since the introduction of new
technology vehicles in 1981.  The challenge now is to ensure that I/M
tests keep pace with changing technology so that they remain an
effective tool for vehicle emission control.
3 Armstrong, J., Brzezinski, D. J., Landman,  L.,  and Glover,  E.  L.,
"Inspection/Maintenance in the 1990's," SAE Paper No. 870621, February
1987.

-------
4.0    Old  Technology  versus  New  Technology

      Old technology, pre-computer-controlled vehicles have emission-
related components that operate on a continuum.  For example,  if the
air-fuel mixture at idle is too rich, then the air-fuel mixture is
likely to be too rich across much of the operating range of the vehicle
(i.e., cruise, acceleration, deceleration).  For this reason a test
performed only at idle or only at 30 mph is likely to identify pre-
computer-controlled vehicles that malfunction to a sufficient degree to
fail the FTP test also.  This continuum characteristic is an inherent
feature of many mechanically controlled systems, including other
emission-control components like the ignition system's distributor,
which controls the ignition timing.

      The newer, computer-controlled vehicles that are becoming an ever
larger fraction of the fleet are not constrained by the continuum
characteristic of mechanical devices.  A computer can include discrete
instructions for the air-fuel mixture at idle that have little bearing
on the mixture at 30 mph or during an acceleration from 10 mph to 20
mph.  For this reason, a vehicle with low emissions at idle or 2500 rpm
or 30 mph can in principal have unacceptably high emissions during other
modes.  Furthermore, EPA studies show that some vehicles with very high
FTP emissions do indeed pass a steady-state test, such as an idle test.
By the same logic, a vehicle with high idle emissions may pass the FTP
because the emissions are low through most of the vehicle's other
operating modes.  An idle test falsely fails such vehicles.  Transient
tests, on the other hand, are responsive to changing emission levels
during different modes of vehicle operation and thus overcome the
limitations of steady-state testing on computer-controlled vehicles.

5.0    IM240  versus  CDH-226

      In the face of changing technology, EPA's objective was to find a
short transient test that would identify high emitting vehicles as
defined by their FTP emissions,  while minimizing errors of commission.
Initially, the CDH-2264 seemed to offer the best possibility for a
viable I/M test.  Since then, EPA has developed the IM240 as a possible
improvement on the CDH-226.
4 Ragazzi,  R. A.,  Stokes, J. T.,  and Gallagher,  G.  L.,  "An Evaluation of
a Colorado Short Vehicle Emission Test (CDH-226) in Predicting Federal
Test Procedure  (FTP) Failures," SAE Paper No. 852111,  October 1985.

-------
      A characteristic of the CDH-226 that stands out when compared to
the UDDS is that the CDH-226 is smoother  (i.e., less transient), so it
requires less throttle action  (see Figure 1 on page 5).  Throttle action
is an important variable affecting vehicle emissions and could be
important in identifying malfunctioning vehicles.

      Take oxygen sensor operation as an example.  As oxygen sensors
deteriorate, their response time lags.  This deteriorating response time
can allow the air-fuel mixture to increasingly deviate from
stoichiometric  (14.7:1), the ratio at which 3-way catalysts most
efficiently oxidize HC and CO and simultaneously reduce NOx  (see Figure
2 below).  This is important because three-way catalyst conversion
efficiency rapidly deteriorates with air-fuel mixture deviations from
stoichiometric.  During steady-state operation, the fuel metering system
adjusts to deliver a stoichiometric mixture, which should stay
relatively constant.  Throttle movement often causes the mixture to
change, and as throttle action increases, the ability of the metering
system to maintain stoichiometry becomes increasingly dependent on the
response time of the oxygen sensor.  A highly transient driving schedule
requires more throttle action than a smooth schedule, so a deteriorated
oxygen sensor is more likely to be identified on a highly transient
schedule than on a smooth schedule.  The same logic can also be extended
to other components of emission control systems.  A driving schedule can
be made too transient, however.  An I/M test requiring more throttle
action than the UDDS might unacceptably increase test variability and
thereby increase the error of commission rate.

      Figure  2:    Air-Fuel   Ratios  and  Conversion  Efficiency
                       100-
                       93-
                       60-
                                  14.4  14.7 15.0
                                  AIR/FUEL RATIO*
                                RICH «   [    • LEAN

      *Converted from equivalence ratios used in the original.

      Source:  Rivard, J. G., "Closed-Loop Electronic Fuel Injection
      Control of the Internal Combustion Engine," SAE Paper No. 730005,
      January 1973, p. 4.

-------
                 Figure 1:  Comparison of Dynamometer Driving Schedules
                                    CDH-226 Driving Schedule
      50-

      40-

Speed  30.
(mph)
      20-

      10-

       0-
         0
50         100         150         200         250         300

                         Time
                         Hills 1 & 2 of the Urban Dynamometer Driving Schedule
      50-

      40-
Speed  30.
(mph)
      20-j

      10

       0
      50-

      40-
Speed  30.
(mph)
      20 1

      10

       0
                   50         100        150        200        250        300

                                            Time



                                     IM240 Driving Schedule
                   50         100        150        200        250        300

                                            Time

-------
      For these reasons, EPA decided to develop a more transient
alternative to the CDH-226, to make the new test similar to the UDDS,
and to evaluate both procedures to determine which is better for I/M
testing.  EPA's alternative was dubbed the IM240 since it was designed
for I/M testing with a duration of 240 seconds.

6.0    IM240  Description

      The IM240 driving schedule is depicted graphically in Figure I.
Appendix 1 provides a speed-versus-time table in one-second increments.
The table also lists the UDDS segments that were used to create the
IM240.

      The IM240 was patterned closely on the first two "hills" of the
UDDS.  It uses actual segments of the UDDS and incorporates the UDDS's
peak speed of 56.7 miles per hour.  Testing over the entire range of
speeds was considered important to detect malfunctioning vehicles given
the discontinuous operating characteristics of computer-controlled
vehicles.  Using actual segments of the UDDS was considered important  to
help improve correlation and minimize errors of commission and errors  of
omission.

      The two large decelerations from hills 1 and 2 are the only
segments that were not taken directly from the UDDS.  The deceleration
rate for both hills was set at 3.5 mph/sec, whereas the maximum
deceleration rate from the UDDS is 3.3 mph/sec.  The higher deceleration
rate prevents the IM240 from exceeding four minutes, which was taken
somewhat arbitrarily to be a measurable upper limit for a test time that
would allow an adequate rate of vehicle processing, or throughput.  The
3.5 mph/sec rate, which has been used successfully in the CDH-226, also
allows time for an idle and an additional transient portion on hill 2
(between 140 seconds and 158 seconds).

      As seen in Appendix 2, the IM240 differs statistically from the
CDH-226.  Because of differences in design, it was speculated that one
of the tests might correlate better than the other to the FTP.

      The IM240 test is run in two segments.  The shorter segment is 94
seconds in duration, which was an informed guess as to the minimum
amount of time needed to realize significant improvements in FTP
correlation.  For comparison, EPA has divided the CDH-226 into two
segments as well, the shorter segment being 86 seconds.  By dividing
each test into two parts, EPA can evaluate the effectiveness of the
entire test as well as the effectiveness of each of the shorter
segments.

-------
      The case procedure stipulates that the engine is running with the
transmission in gear before the driving schedule begins.   Zxhaust
sampling begins simultaneously with the start of the driving schedule.

      IM240 testing is being performed separately and in conjunction
with other short tests, including the CDH-226, in the Composite I/M Test
Procedure, which is described below.

7.0    Composite  I/M  Test  Procedure

      The EPA has devised the multi-purpose Composite I/M Test Procedure
(CITP) to evaluate the effectiveness of the IM240,  the CDH-226, and
potential steady-state alternatives to current I/M tests.  The goal of
the program is to identify emission tests which balance the need for
high FTP correlation and high identification rates against cost,
equipment, and time requirements.  Acceptable alternative tests would be
sophisticated enough to measure the emissions of new technology
vehicles adequately while conforming to the constraints of an I/M
program.

      CITP testing is being performed at EPA's Motor Vehicle Emission
Laboratory  (MVEL) in Ann Arbor, Michigan and under contract at the
Automotive Testing Laboratories  (ATL) facility in New Carlisle, Indiana,
just outside of South Bend.  All Emission Factor Program5 test vehicles
receive the CITP after the as-received FTP test on Indolene test fuel.

      7 .1    Dynamometer  Settings

      The CITP sequence consists of 11 test modes run over 77 minutes.
At EPA's lab,  che CITP is divided into two parts, A and B,  which differ
by the dynamometer settings used (see Table 1).   (Because of different
equipment configurations, testing at the ATL facility is done in four
parts.)  Part A is performed using the certification dynamometer
settings,  which require an expensive multiple curve dynamometer and a
complicated process for determining the proper road load and inertia
weight settings for each vehicle.  In Part B,  the dynamometer settings
are limited in order to evaluate the tradeoff between cost and FTP
correlation that is associated with less sophisticated dynamometers.
5 The Emission Factor Program tests vehicles owned by the general
public.  Data from these in-use vehicles are used with a computer  model
known as MOBILE4 to calculate the emission rates of in-use vehicles.
These emission rates are then used with air quality models to estimate
the contribution of mobile source emissions to ambient air pollution.

-------

-------
           ATTACHMENT  A

           Specifications

                 for

Electric  Chassis  Dynamometers
      U.S. Environmental Protection Agency

         Motor Vehicle Emission Laboratory
             2565 Plymouth Road
            Ann Arbor, MI 48105
                                 ATTACHMENT A
                                 RFP C10008 IT 1
                                 37 Pages

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     Specifications for  Electric  Chassis Dynamometers
                           Table of Contents
1.0    General Features	,	1
      1.1    Equipment	1
      1.2    Component  Preparation	2
      1.3    Documentation	2
      1.4    Ambient  Operating Conditions	3
      1,5    Electrical Specifications	3
      1.6    Electronic Control	4
      1.7    Roll(s)	4
      1.8    Inertia  Simulation	5
      1.9    Vehicle Restraint System	6
      1.10  Lift  Platform and  Roll  Brakes	..6
      1.11  Safety Devices	6
      1.12  Instrumentation	7
      1.13  Bearings and Lubrication Intervals	8
      1.14  Covering of the Dynamometer Pit	9

2.0    4 Wheel-Drive   Chassis Dynamometer  Requirements	9
      2.1    Set-up	9
      2.2    Requirements for Roll Synchronization	10
      2.3    Operation  Mode  2WD/4WD	10
      2.4    Wheelbase   Adjustment	10
      2.5    Vehicle Restraint System	10

3.0   System   Processor   Requirements	11
      3.1    General Computer Requirements	11
      3.2    Processor  Modes/Functions	11
            3.2.1  Road Load Inertia Simulation Mode	12
            3.2.2  Self-motoring Mode	13
            3.2.3  Dynamometer and  Vehicle Coastdown Test	14
      3.3    Interface with Master/Host Computer System	15
      3.4    Real-Time Data Monitoring	15
      3.5    Electric Dynamometer Data Acquisition Package	16

4.0   Acceptance Tests, Procedures, and Criteria	17
      4.1    General Acceptance Provisions	17
      4.2    Testing  Requirements  and Overview	17
            4.2.1  Reporting	17
            4.2.2  Vehicle Torque Wheel System	18
            4.2.3  Data Acquisition (Hardware/Software)	19
            4.2.4  Data Analysis and Presentation	19

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Specifications for Electric  Chassis  Dynamometers
 4.3   Component Review and Calibration Tests	19
       4.3.1  Installation and Mechanical Review	19
       4.3.2  Structural and Dimensional Review	19
              4.3.2.1 Frame	,	19
              4.3.2.2 Bearings  and Lubrication	20
              4.3.2.3 Roller  Geometry	20
       4.3.3  System Operation and Calibration Review	20
              4.3.3.1 Mechanical Inertia Determination	20
              4.3.3.2 Torque  Cell  Calibration	21
              4.3.3.3 Torque Transducer Virtual Span & Zero	21
              4.3.3.4 Speed  Measurement	22
              4.3.3.5 Acceleration Meas'irement	22
              4.3.3.6 Tune Measurement	22
              4.3.3.7 Computer	22
 4.4   Dynamometer Characterization Tests	22
       4.4.1  Endurance  Testing	22
       4.4.2  Electrical Inertia Simulation Response	23
       4.4.3  Operational Response Characterization	23
              4.4.3.1 Dynamometer  Self-motoring	23
              4.4.3.2 Steady State Speed Loading	26
              4.4.3.3 Fixed Acceleration Rate	26
              4.4.3.4 Neutral Coastdown Rolling Load	27
              4.4.3.5 Urban Dynamometer Driving Schedule (UDDS-505 seconds) 27


 Appendices:
       A     Electric Dynamometer Acceptance Cross Reference
       B     Figure 1      Dynamometer Rise and Settling Time Illustration
              Figure 2      Steady State Dynamometer Load Curves
       C     Figure 3      Force versus Acceleration (dV/dt)
              Figure 4      Example of Mean Force Value Graphs
       D     Symbols and Specification Terminology
       E     Glossary of Acceptance Criteria Terminology
       F     Response Characteristics of a Second Order System to a Unit S tep Function

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     Specifications  for Electric  Chassis  Dynamometers


1.0    General  Features

       Federal regulations for exhaust emissions and fuel economy of motor vehicles specify tests
       using chassis dynamometers. The purpose of the chassis dynamometer is to duplicate the
       forces encountered by a vehicle moving on a road by modeling those characteristics with a
       stationary vehicle on a rotating surface. EPA envisions a variety of testing needs to address
       future regulations. A key feature of the recent Qean Air Act Amendments is that the test
       conditions appropriately simulate "real-world" conditions.

       The optimal dynamometer utilizes the latest technology through a digitally-controlled,
       electrically-activated, motor-absorber that supplements mechanical inertia, optional
       flywheels, and frictional forces with electrical load forces based on specific equations and
       coefficients. The test cell, dynamometer, and vehicle operate as a system under various
       ambient conditions to provide maximum flexibility and ease of operation. In all cases, the
       loading capabilities, control algorithms and other operating characteristics of these
       dynamometers must be able to accurately and precisely simulate the forces encountered by a
       vehicle on the road.

       While twin roll dynamometers have traditionally been used at MVEL for most testing, this
       acquisition allows vehicle loading by means of either a twin roll or single roll configuration
       if the performance specifications contained herein are met The twin roll configuration shall
       have synchronous roll speeds and shall apply the total load force through a symmetrically
       balanced design so that the  forces at the roll/tire contact points contribute uniformly to the
       total simulation of the  road forces. The single roll dynamometer shall have a 48" diameter
       roll and shall be the system configuration installed in the Cold Test Facility (CTF)  at a
       minimum.

       The chassis dynamometer shall conform to the requirements specified herein.

1.1    Equipment

       The dynamometer shall be designed and constructed to be capable of operating on  a
       continuous basis (24 hours per day, 7 days per week). It shall withstand all static and
       dynamic loads which are encountered during  vehicle testing, and shall not produce any
       vibrations which may impair the operation of the vehicle or dynamometer.

       The dynamometer components shall be capable of withstanding shock loading from
       maximum acceleration/deceleration forces, such as locked vehicle brake at 60 mph, wide
       open  throttle (WOT), emergency shutdown, or any system malfunction(s) that induces
       abrupt forces, without damage to any component(s).

       The dynamometer system shall consist of the following components, at a minimum,
       arranged in a configuration that optimizes the physical dimensions, system response
       characteristics, and flexibility to simulate various loading schemes:

              - the roll(s) in a structure or frame suitable for this application
              - a vehicle inertia simulation system
              - an electric motor-absorber system
              - all pneumatic and/or hydraulic components
              - all operator and driver interface panels, displays, controls, and interface wiring for
               the computer system
              - all calibration devices
              - a means to ensure safe and efficient installation and removal of the vehicle
              - a vehicle restraint system to limit the dynamic lateral and fore/art travel of the   -
               vehicle
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     Specifications  for Electric  Chassis  Dynamometers


             • safety equipment, including noise and EFI suppression
             • all electrical cabling, piping, tubing, and cabinets
             - installation, checkout, and warranty
             - complete documentation including construction, installation, operation, service,
              parts, etc.

      Additional details of these requirements are contained in other paragraphs throughout this
      document.

      The dynamometers shall be installed in the test cells as specified by Delivery Order, which
      shall include a test cell configuration plan.

      Repair service and spare parts shall be available within one working day of request during
      the one year warranty period.

1.2   Component Preparation

      All surfaces of the dynamometer system shall be treated with protective coatings (such as
      plating, primers, epoxy, etc.) or made from materials that will prevent rust, scaling,
      flaking, or chalking under all the operating conditions of the test cell environment.

      Rotating parts such as roll(s), flywheels or shafts, and other non-paintable parts, shall be
      protected from corrosion by applying suitable treatments.

1.3   Documentation

      Five (5) copies of the documentation of the dynamometer system shall be provided to the
      Project Officer upon delivery of each dynamometer.  The documentation shall be in English
      and shall include, at a minimum, the following:

          • the dynamometer mechanical layout
          - schematics of all pneumatic and hydraulic components
          • color coded and/or numbered schematics and wiring lists of all electric components
          - technical and operational manual(s), including a complete description of the system
           control algorithms, performance measures, calibration procedures, system hardware
           and software operation, response characteristics and system source code.
          - pans list(s)
          - recommended, on-hand, spare parts list
          • maintenance and calibration instructions

      The operation manual(s) shall include complete information on the dynamometer's
      functions, capabilities and user interface procedures.

      The parts list shall include, at a minimum, the following:

          • All subcontractors' parts, ID enable the government to obtain precise information,
           including addresses and phone numbers
          - The model and/or part number designations of ail component parts

      One set of recommended on-hand spare parts shall be supplied, at time of installation, for
      each dynamometer provided. As an option, the contractor may guarantee delivery of these
      parts per the one working day time period specified in Section 1.1.
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     Specifications for  Electric  Chassis  Dynamometers


1.4   Ambient Operating Conditions

      The dynamometer shall be used to test vehicles exposed to the following ambient
      conditions: (See Note)

             test cell temperature:                                         0 to +110 °F
             relative humidity:                                               0 to 90%
             altitude:                up to 3,300 feet for all units except the Denver location

      Note: The dynamometer performance shall not be affected by the conditions applied to the
      vehicle test environment The vehicle test environment and dynamometer operating
      environment may be separately controlled spaces. The objective is to maintain frictional
      stability and to minimise component exposure to adverse conditions. Air for the
      temperature control of the dynamometer shall be taken from a dry air source so that
      condensation in the dynamometer system is prevented.

1.5   Electrical  Specifications

      The system shall operate with the following electrical voltages:
                                                                                   •
             120 V (± 10%) 60 Hz      instrumentation only
             480 V (± 10%) 60 Hz      (three phase, four wire)

      The motor-absorber electrical interface shall be regenerative (i.e., generated power shall be
      fed back to the grid.)
      The equipment shall be grouped into the following sections:

             1. electronic and display
             2.  power

      The electronic and display section shall be installed in a standard 19" rack, which may be in
      a separate cabinet from the power section.  The operator interface cabinet shall be located in
      the dynamometer control room for operator access.

      The controls at the electronic and display section shall include, at a minimum:

             • emergency stop switch
             - operator interface and displays

      Two switches shall also be accessible from the vehicle driver's seat door. If these switches
      are operable from the control room, a safety interlock or alert to the driver shall be installed.

             • vehicle alignment switch
             . lift platform switch
             • roll brake switch

      The minimum requirements for instrumentation at the power section are as follows:

             - emergency stop switch
             - main power switch
             - armature-current display (may be installed inside the cabinet)
             - armature-voltage display (may be installed inside the cabinet)
             - running-time (hour) meter
             - fault protection circuits)

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     Specifications for  Electric  Chassis  Dynamometers


       Installation shall conform to the latest editions of the National Electric Code (NEC) and
       Building Officials Code Administrators International (BOCA).

1.6    Electronic Control

       The speed and load control circuitry shall be based on digital microcomputers or
       microprocessors. Low current or power conversion circuitry may be excluded from this
       requirement.

       The electrical power driving all electrically actuated relays, solenoids, valves, and motors
       shall be electrically isolated from the power source for the dynamometer control circuitry,
       computer, and interfaces.

       All electrically actuated relays, solenoids, and valves shall be protected by zero switching
       or diode clamping so that no back EMF electrical noise is generated,

       The electrical power driving the dynamometer control circuits shall be immune to all
       electrical noise. The system shall not feed damaging or detrimental electrical noise into the
       power grid.  Electromagnetic fields caused by the dynamometer shall be controlled or
       suppressed to prevent any interference in the test vehicle or dynamometer
       electrical/electronic control systems. The contractor shall provide and install any isolation
       devices required for operation.

       The dynamometer shall be protected from uncontrolled acceleration of the motor-absorber.
       The motor-absorber shall also have current limit protection to prevent system damage from
       power grid faults of short duration (<20 ms).

1.7    Rollfs)

       A roll shall be defined as a cylindrical contact surface that applies the load forces to the tires
       on the test vehicle's drive axle(s). A roll may be a single cylinder or mechanically linked
       multiple cylinders. A twin roll dynamometer cradle consists of two rolls per vehicle drive
       axle which operate at synchronous speeds and impose forces at each tire contact point that
       are similar in magnitude.  A single roll dynamometer consists of one roll per vehicle drive
       axle.  The rolls, bearings, and power transfer loading devices shall be sized and configured
       to withstand the road load forces and axle loads of the specific test vehicles. These forces
       and loads shall include those values typically encountered from on-road vehicle
       performance tests conducted at wide open throttle from zero up to a maximum of 100 mph.

       The requirements shall be the following:

             nominal roll diameter (twin roll)                 20 inches
             tire contact angle (twin roll center spacing)        66° on a 24" contact circle
             twin roll center spacing                   => 2 (roll diam/2 + 24/2)(sin 33°)
             nominal roll diameter (single roll)               48 inches
             roll diameter determination tolerance             ± 0.02% of nominal diameter
             difference in cylinder diameters per roll set       ± 0.02% of nominal diameter
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     Specifications  for Electric  Chassis  Dynamometers


             roll width spacing shall accommodate:
                 vehicle inside track width (LDV) *           36 inches
                 vehicle outside track width (LDV)            86 inches
                 vehicle inside track width (MDV) *           36 inches
                 vehicle outside track width (MDV)           108 inches

             roll surface roughness                         (See Note)
             roll surface minimum hardness                  Rockwell B90
             roll dynamic balance quality (twin roll)           ANSI STD G2.5
             roll dynamic balance quality (single roll)          ANSI STD G6.3
             roll axis parallelism (twin roll)                   0.020 inches TIR *
             roll concentricity (twin roll)                     0.004 inches TIR
             roll concentricity (single roll)                   0.010 inches TIR

          *  LDV = Light Duty Vehicle
             MDV = Medium Duty Vehicle
             TIR = Total Indicated Runout

     • Note: Roll surface finish shall provide minimum tire slippage and a tractive effort that is
      comparable to a vehicle operating on a typical dry, road surface. Roll surface roughness
      shall also not produce abnormal tire tread wear.

      The speed of twin rolls shall be synchronized to within ±0.1 mph at all operating
      conditions. Synchronization shall be accomplished by mechanical or electrical coupling.
      The total force applied by the roll(s) to the vehicle shall be the sum of the forces (including
      inertia) from each tire/roll contact point The parasitic loss of the coupling device shall be
      stable and compensated for during all modes of vehicle or dynamometer operation.

      For the 4WD system, the dynamometer rolls shall be nominally installed flush with the
      level, finished floor. When testing on a 2WD system, the contractor shall provide a
      method for maintaining the vehicle in a horizontal (± 1% grade) attitude when the drive tires
      are supported by the roll(s).  The overall width of the LDV dynamometer shall be
      minimized to fit within the test cell, which will have an interior width of 16 feet The
      overall width of the MDV dynamometer shall be less than 20 feet The dynamometer
      frames shall be supported above the subfloor space in a manner that allows air recirculation
      in the subfloor area.  The test vehicle is to be approximately located at the geometric center
      of the air flow stream of the test chamber, and in a consistent relation to the exhaust
      sampling system connectors which shall be in fixed locations in the subfloor space. The
      dynamometers) and the vehicle restraint system(s) shall be capable of testing both rear
      wheel drive vehicles and front wheel drive vehicles.

1.8   Inertia Simulation

      The total inertia (mechanical plus electrical) to be simulated shall be selectable to within at
      least ± 10 pounds. This value shall be used to calculate the total road force required. The
      accuracy of the total road force imposed, including the inertia force, shall be within ± 1%
      of this calculated formula value under all operating conditions within acceleration rates of ±
      8 mph/sec. The electrical inertia simulation shall provide response characteristics that
      result in total torque wheel loading that is comparable to a mechanical inertia system. For
      LDV dynamometers, the range of total inertia simulation shall be from 1,000 Ibs. to 6,000
      Ibs. For MDV vehicles, the range of total inertia simulation shall be from 1,000 Ibs. to
      12,000 Ibs.
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     Specifications for  Electric  Chassis  Dynamometers


       The contractor shall measure and verify the value of the base inertia and all incremental
       mechanical inertia values of the dynamometers. Results of these tests shall be included in
       the documentation.

       Any mechanical flywheels used as part of the inertia shall be dynamically balanced to the
       same quality standard, or better, as used for the roll(s). The control panel shall provide an
       indication and verification of the positive engagement and disengagement for each
       flywheel. The contractor shall provide, during any continuous closed throttle deceleration
       to zero, a means of reducing the braking force required from the drive axle. This force
       reduction shall be sufficient to prevent drive axle brake damage or failure.

1.9    Vehicle Restraint System

       A vehicle restraint system shall be provided and installed with each dynamometer in a
       manner that enables unobstructed vehicle ingress and egress from any perimeter wall of the
       test celL

       The vehicle restraint system shall safely restrain all vehicles at all operating conditions. The
       vehicle restraint system shall center the drive wheel(s) of the vehicle on the roll(s).
                                                                                      •
       The vehicle restraint system shall limit lateral and fore/aft motion of the vehicle to ± 0.5"
       without imparting any adverse vertical or horizontal forces on the vehicle or vehicle tires,
       and shall be easily installed, or engaged by the operator in less than ten minutes. Vehicle
       removal from the restraint system and the test cell shall be possible in less than two
       minutes.

1.10   Lift Platform and Roll Brakes

       A lift platform situated between the rolls (on a twin roll configuration) shall be installed.

       A roll brake which securely locks the roll(s) shall be installed

       When the lift platform is raised and the roll brake is actuated, the vehicle shall enter and
       leave the dynamometer without causing roll spin.

       Operation of the roll brake shall be  independent of the  lift platform.

       The lift platform shall be capable of being activated by a driver seated in the vehicle.

       The lift platform shall be operable only when the roll(s) are not rotating. A roll speed
       interlock system shall prevent raising of the lift platform and non-emergency engagement of
       the roll brakes while the roll(s) are rotating.

       The lift platform shall be capable of holding a vehicle in the raised position for a minimum
       of 24 hours.

       The roll brake and lift platform shall be replaceable within four hours and without removing
       any system components which may change the dynamometer calibration.

1.11   Safety Devices

       All safety devices  for protection of the equipment shall be as independent of the processor
       as practical.


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     Specifications  for Electric Chassis  Dynamometers


      Warning lights on the dynamometer, indicating the status of the lift platform and roll
      brakes, shall be visible from the driver of the vehicle.

      The dynamometer shall have the following personnel safety devices:

             A safety barrier shall be installed to prevent personnel contact with the roll(s) during
             vehicle testing and during dynamometer roll operation without a vehicle. If a single
             roll dynamometer consists of two roller cylinders, or a twin roll cradle consists of
             four roller cylinders, the area between the rolls/cylinders shall be covered to provide
             a surface that facilitates personnel safety and allows vehicle movement.

             An emergency stop switch shall be installed in the dynamometer test cell, at the
             vehicle, and at the electronic and display cabinet, and also at the power cabinet if it
             is separate.  The emergency stop function shall cause shutdown (braking) of the
             dynamometer using the electric motor-absorber working at the maximum current
             limits.  In the event the electric motor-absorber is unable to decelerate the roll(s) to
             zero, the roll brake may be used. In all cases, the roll(s) shall be decelerated to zero
             mph in less than 5 seconds and shall not damage the dynamometer system.

             An emergency shutdown function shall be triggered automatically by the processor
             when any of the following limits are exceeded:

                    - dynamometer's maximum speed (fixed value)
                    - vehicle's maximum speed (value input during calibration)
                    - vehicular movement (>0.5 inches)

             An emergency warning function shall be triggered automatically by the processor
             when any of the following limits are exceeded:

                    - excessive armature or field current of the motor-absorber
                    - overheating of the motor-absorber
                    - malfunction of the dynamometer cooling system
                    - malfunction of the power transfer system
                    - power failure
                    - other conditions needed to protect the dynamometer or personnel
             These conditions do not warrant an immediate shutdown of the dynamometer
             system but rather a warning of a condition that requires immediate attention.

             An indicator of activation of the emergency stop function, shutdown, or warning
             shall be installed in the dynamometer test cell (visible from the vehicle driver's seat)
             and in the dynamometer control room. The indicator shall be operational at all
                   including during power failures.
1.12   Instrumentation,

       Display meters shall be installed to provide for speed, force, and horsepower readings for
       both the vehicle driver and the operator console.

       The roll revolution and associated speed measurements shall be monitored by digital or
       optical sensors. A speed measurement method on each roll, and one for the vehicle wheel
       shall be installed to monitor roll(s) speed, to determine the angular velocity of the drive tire,
       and to verify roll speed synchronization under all test conditions. Measured speed shall
       have an accuracy and a resolution of a minimum of ± 0.05 mph at any speed. The speed

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     Specifications  for  Electric  Chassis  Dynamometers


      measurement system shall be drift-free and shall require no analog calibration. Test
      distance driven shall be determined to a resolution of one pan in 2000.

      The acceleration and deceleration rates (mph/sec) of the roU(s) shall be determined by
      electrical or numerical methods.  All acceleration rates shall be accurate to within ± 0.01
      mph/sec or ± 1% of the acceleration rate, whichever is greater, and shall be determined
      within 100 ms of true occurrence.

      The dynamometer shall have a torque measurement system to indicate the forces being
      applied to the dynamometer roll(s). This system shall be capable of indicating torque
      readings to a resolution of 0.05% of rated output or ± 0.2 ft-lbs, and shall be capable of
      sampling data at a rate of 1 KHz or higher.

      The performance specifications of the torque transducer shall be the following:

                 hysteresis:         less than ± 0.1 % of rated output
             zero/shunt drift         less than ± 0.1 % of rated output in a 24 hour period
               repeatability:         less than ± 0.05% of rated output
                nonlinearity:         less than ±0.1% of rated output (See Note)
                  accuracy:         less than ± 0.1% of rated output at all values between.
                                    ± 10-100% of rated output based on the best fit
                                    calibration regression

                                    Note: Nonlinearity is defined as the deviation at mid-
                                    scale from a straight line connecting the zero and ± full-
                                    scale values, expressed as a percent of the rated output.

      Calibration of the torque transducer for both positive and negative torque by the dead
      weight lever arm technique shall be provided. An electronic shunt calibration value shall be
      correlated to this dead weight technique. Torque transducer verification procedures under
      dynamic operation shall also be provided,

      Elapsed time measurements shall have an accuracy and resolution of at least ± 0.01
      seconds.

      The design of the road load control system shall measure the force and determine the
      horsepower delivered at the roll surface(s) based on the applied torques, accelerations, and
      speeds of the roll(s). This system shall compensate for the mass and parasitic friction both
      inside and outside the control loop of the dynamometer.

      Separate digital displays, easily seen by the driver, shall be provided for the following
      parameters, at a minimum-

             Roll speed (mph)
             Tractive force (Ibs)
             Tractive horsepower (hp)

1.13  Bearings and Lubrication Intervals

      All bearings, gears, or coupling devices shall be designed to have minimum and stabilized
      frictional losses.

      All bearings shall have a service life of at least 30,000 hours. All parts requiring
      lubrication shall be lubricated before delivery. All lubrication points shall be easily
      accessible and well documented. The lubricants, lubrication  system, or the dynamometer
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     Specifications for  Electric  Chassis  Dynamometers


       system configuration shall not generate, into the test cell enclosure, hydrocarbon emissions
       that would adversely affect a vehicle running loss test at 100 °F.

       The fractional losses of the dynamometer at all environmental conditions shall be
       thoroughly characterized for all modes of operation. Steady speed (50 mph) factional
       losses shall remain within ± 0.1 hp of the final stabilized value following a ten minute
       warm-up period.

1.14   Covering of the Dynamometer Pit

       The area around the roll(s) shall be covered by slip-resistant plates capable of supporting
       test vehicles.

       All floor plates shall be secure, and if moveable during dynamometer wheeibase
       adjustments, shall not cause any opening in the floor surface following the adjustment.

       The weight of a single plate shall not exceed 115 Ibs.

2.0    4  Wheel-Drive Chassis Dynamometer Requirements
                                                                                    «
       The basic requirements for a 2WD chassis dynamometer shall also apply to the 4WD
       version. Additional 4WD requirements are described in this section, and are to be applied
       as appropriate to single or twin roll configurations.

2.1    Set-up

       The dynamometer chassis frames shall be installed on a support base and shall provide
       torsional stiffness and alignment performance.

       The front and rear roll, or sets of rolls, shall be parallel to within 0.08 inches as measured
       by the cemerline differential across the maximum roll width.

       The front and rear roll, or sets of rolls, shall be electrically or electrohydraulically
       adjustable to the vehicle wheelbase. This adjustment process shall indicate the final
       wheelbase distance and shall utilize adjustment methods to assure the vehicle tire contact
       points are uniformly loaded.  After adjustment, the roll chassis positions shall remain
       positively fixed on the base frame, even during power or hydraulic failures.

       Operation of either 4WD or 2WD shall be selectable. Operation in the 2WD mode shall be
       possible with either roll or set of roils. The non-driven rolls, in a twin roll configuration,
       shall be locked with the  lift platform down to act as a vehicle wheel chock.

       On a twin roll configuration, a mechanism or method controlled by the processor shall
       provide speed synchronization between the front and rear roll of each drive axle cradle.

       On a twin roll configuration, to ensure ease of vehicle handling when entering or leaving
       the dynamometer, each set of twin rolls shall have a lift platform and a roll brake. The
       raising and lowering of both lifts shall be synchronized in the 4WD mode.
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     Specifications  for Electric  Chassis  Dynamometers


2.2    Requirements for Roll Synchronization

       The speed of all rolls shall be synchronized to within ± 0.1 mph at all operating conditions.

       The parasitic losses of any mechanical synchronization shall be independent of the selected
       wheelbase and shall be stable and compensated for, by the system, under all operating
       modes.

2.3    Operation Mode 2WD/4WD

       The 4WD dynamometer shall be usable as a 2WD dynamometer as well Either roll or set
       of rolls (front or back) shall be usable for 2WD operation.

       The synchronization of the rolls or roll sets shall be controllable by the processor. The
       display shall indicate the configuration of the dynamometer at all times.

       The configuration of the dynamometer (4WD or 2WD) shall be stored in the road load
       model or test data set

       The roll or set of rolls which is not used in the 2WD configuration shall be locked using the
       roll brake.

       The calibration, compensation, and storage of the dynamometer losses shall be maintained
       in both 2WD and 4WD configurations.

2.4    Wheelbase Adjustment

       The distance between the front and back roll, or sets of rolls, shall be continuously
       adjustable between 80 and 130 inches. The time required for adjusting the dynamometer to
       any wheelbase in the 80 to 130 inch range shall not exceed five minutes. A provision to
       extend the wheelbase to 180 inches shall be installed with setup requiring no more than one
       hour.

       The wheelbase spacing shall be automatically adjustable to the vehicle .wheelbase, this
       condition shall be indicated by a zero speed, null restraint force and centered axles.

       The wheelbase shall be adjustable while the dynamometer is in either 2WD or 4WD
       configuration.

       The value of the final wheelbase setting shall be read and stored to within ±0.2% of the
       nominal wheelbase.

2.5    Vehicle Restraint System

       A vehicle restraint system shall be installed with each dynamometer that enables
       unobstructed vehicle ingress and egress from any perimeter wall of the test cell

       The vehicle restraint system shall be capable of safely restraining all vehicles at all operating
       conditions.

       The vehicle restraint system shall limit lateral and fore/aft motion of the vehicle to ± 0.5"
       without imparting any adverse vertical or horizontal force on the vehicle, and shall be easily
       installed, or engaged by the operator in less than ten minutes. Vehicle removal from the
       restraints and test cell shall be possible in less than two minutes.

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     Specifications for  Electric  Chassis  Dynamometers


3 . 0    System  Processor Requirements

3. 1     General Computer Requirements

       The. signal cabling shall not cause malfunctions due to capacitive or inductive interference.

       Dynamometer operating system software, control software and parameters, and data
       acquisition interfaces shall be stored and accessed using commercially available standard
       microcomputer hardware.  The contractor shall provide a complete description of the
       hardware and operating software. Access to all software (including source code) and
       operation parameters shall be provided

       All analog input and output signal converters shall have a nominal ± ten volt range with a
       minimum of 0.005 volts per bit resolution.

       All digital input/output channels shall be 0 to 5 volt TTL (transistor-transistor-logic) and
       shall be optically isolated from their source.

       Error messages and the operating hours counter shall function at all times.
                                                                                  *
       It shall be possible for personnel without special computer experience to operate the
       dynamometer processor and the peripheral units, including the input of parameter changes.
       The dynamometer shall operate in both a local mode without interaction with a remote
       computer system, and in a client/server mode, while connected to a remote system that
       contains vehicle test parameters and data sets^uid may be used to receive or send data sets
       of test information or calibration.

3.2     Processor Modes/Functions

       The dynamometer processor shall support, at a minimum, the following operation modes
       and tests:

             - road load simulation mode
             - self-motoring mode
             - dynamometer coastdown test
             - quick check coastdown test
             - speed control mode
             - torque control mode
             - acceleration mode
             . calibration nvxte
       The dynamometer processor shall check all processor functions (e.g., CPU, memory, and
       input/output channels) using an on-line diagnostics program.
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     Specifications  for Electric  Chassis Dynamometers
3.2.1   Road Load ^n^rria Simulation Mode

       The load applied by the dynamometer shall simulate the rolling resistance, aerodynamic
       drag, and inertia forces that occur on the road according to the following formula:

                    FR  =*  A + B*V  + C*V2+ D*W  -i-  M*dV/dt   (See Note)
       where:
             FR= total vehicle road load force to be applied at the surfaces of the rolls
             A a constant load coefficient (friction)
             B a load coefficient dependent on velocity (speed boost)
             C = load coefficient dependent on velocity squared (windage)
             D » grade coefficient (-,+) [sin 6 ]
             W = weight of vehicle
             M = effective vehicle mass, taking into account the rotational masses
             V = velocity of the roller surfaces
             dV / dt = acceleration rate of the roller surfaces

       Note: The total force is the sum of the individual forces applied by each roller surface.
                                                                                    *
       The simulation of the total road force, including the inertia force shall be ± 1 % of its
       formula value under all operating conditions and at all velocities.  All dynamometer
       configurations, mechanical and electrical, shall produce comparable results that are not
       significantly different from the standpoint of accuracy, precision, or reproducibility.

       The system response time shall be less than 100 milliseconds. System response time shall
       be defined as the time lag between a step change in demanded force at the roll surface, and
       the occurrence of 90% of the final demand value. Total response shall include mechanical
       delay, measurement lag. computational time, and power control electrical response
       parameters that will be combined to provide a critically damped response function.
       Appendices E and F provide response definitions.

       In road load simulation mode, sets of coefficients containing road load curves and inertias
       shall be directly accessible from the system storage device within ten seconds.

       All data sets shall have a sufficient number of characters in their nomenclature to provide
       uniquely identifiable names for retrieval.

       In simulation mode, all functions shall be performed, and the error value monitored by the
       dynamometer processor.

       Calibration for frictional losses shall be automated.

       For any inertia configuration, the processor shall determine a friction curve using a steady
       speed, constant acceleration or deceleration, or a coastdown procedure. The user shall
       have the capability to manually set the frictional loss coefficients.

       The frictional losses shall be compensated for over the entire speed range.
                                         Page 12                      6/5/91   4:50 PM

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     Specifications  for  Electric  Chassis  Dynamometers


       The frictional losses shall be modeled by the following equation:

             F   =a  +b*v+c*v  +d*v  + e  * (m * dv/dt)     (See Note)
              o      o     o         o        o       o

             where:

             F  = total dynamometer frictional losses outside the force control loop

             a = constant frictional loss coefficient
              o
             b = frictionai loss coefficient dependent on velocity

             c = fricrionai loss coefficient dependent on velocity squared

             d = frictional loss coefficient dependent on velocity cubed  (optional)

             e = frictional loss coefficient dependent on acceleration

             m = effective vehicle mass, taking the rotational masses into account
             v = velocity of the roll surfaces

       Note: Frictional losses shall be determined on each roll, incremental mechanical inertia,
       and coupler and shall be compensated for in the road load function. These losses shall also
       be determined as a function of the acceleration power transfer.

       The system shall support polynomial fits up to 3rd order.

       The dynamometer processor shall retrieve  historical data sets from on-line disk storage or
       from a remote server.

       The prevailing dynamometer rotational direction shall be part of the stored calibration data,
       as well as a specific date/time stamp associated with each run.

       All dynamometer loss coefficients shall be part of the long-term data storage, and shall be
       readily available for trend analysis and quality control functions.

3.2.2  Self-motoring Mode

       The motor-absorber system shall motor both the roll(s) and the inertia system. This shall
       allow the following procedures to be executed, at  a minimum-

             - vehicle alignment
             - dynamometer warm-up
             - coastdown and acceleration tests
             - speed signal checks
             - dynamometer calibration
             - dynamic torque verification
             - system response characterization

       The desired acceleration/deceleration rate and final speed shall be specified by the operator
       and automatically controlled through the dynamometer processor.

       The roll(s)  shall be motored, or "jogged", during vehicle alignment by use of a momentary
       contact device.

       The motor-absorber shall be capable of accelerations and decelerations of the base
       mechanical inertia at any rate between 0 and 10 mph/sec.
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     Specifications for  Electric  Chassis  Dynamometers
3.2.3  Dynamometer and Vehicle Coastdown Test

      The dynamometer shall perform continuous or incremental coastdown tests. These tests
      shall be performed with or without a vehicle on the roll(s). If a vehicle is used, the
      transmission shall be in neutral during the coastdown.

      During the coastdown test, the dynamometer shall achieve a stabilized speed above the
      selected upper speed limit (v^p^.) and then coast down to the selected lower speed limit
      (vlower) ^der *"* influence ofthe selected road load model Speed, torque, acceleration,
      time, and other pertinent data shall be digitally recorded or logged at the specific sampling
      rate (0.1 or 1.0s) for subsequent regression analysis.

      The maximum vupper shall be 80.0 mph.
      The minimum Vjowef shall be 5.0 mph.
      The minimum vmtervaj shall be 5.0 mph.
      The coastdown range is vupper to vlower


      The number of coastdowns to be performed shall be selectable by the operator.

      At the conclusion of each coastdown the following values shall be displayed, at a
      minimum;

            For the selected coastdown range:

                  - the upper and lower speeds of the range

                  • the elapsed range time:  t       -  t
                                          upper    lower

                  - calculated coefficients a , b , andc  using the coastdown data of the entire
                                       00     O
            curve

            For each selected speed interval within the coastdown range:

                - the upper and lower speeds of the interval

                - the elapsed interval time:  t   - t
                                        vl   V2

                - actual absorbed horsepower

                - difference between motor-absorber power and actual absorbed power.

      The operator shall have the ability to automatically conduct the standard coastdown test as
      defined in 40CFR §86.118-78. Tide 40: Chapter I - Environmental Protection Agency,
      Pan 86, Subpart B, Section-86.118-78 - Dynamometer Calibration.
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     Specifications  for Electric   Chassis  Dynamometers


3.3    Interface with Master/Host Computer System

       The dynamometer processor shall have the ability to communicate using, at a minimum, an
       RS-232 interface to a master/host computer system. IEEE-488, RS-422, Ethernet, and
       Appletalk are acceptable supplemental protocols. The specifications for the RS-232
       communication to the master/host computer shall be as follows:

             selectable baud rate(s):      1200, 2400,4800, 9600, or 19200 bits per second
             selectable character size:     7 bits, or 8 bits
             selectable parity:           even, odd, or none
             selectable parity bit*        0 bit, or  1 bit

       The dynamometer processor shall exchange all necessary information, including
       commands, data, error messages, and reports with the master/host computer system. The
       dynamometer processor shall provide the remote computer system with the following
       values, at a minimum:

          - all site and vehicle data relevant to the test setup
          - operation mode
          - data set name of road load model
          • mechanical, electrical, and total inertia simulated on each roll
          - coefficients of road load model
          • coefficients of dynamometer loss curve on each roll
          - the effective rolling radius of the tires, as determined under minimum load (neutral
           coast down or steady speed motoring) at 50 mph.

       The dynamometer shall be operational in a remote mode with minimal interaction by the
       operator. In this mode, any test data or commands that must be entered to configure or
       control the dynamometer for a test may be accessed from a remote computer system instead
       of from the dynamometer processor's input devices, such as keyboard, keypad, or mouse.

3.4    Real-Time Data Monitoring

       During dynamometer operation, the following real-time data (either as analog, digital, or
       computed data) shall be available for a remote computer, either directly from the
       dynamometer hardware or from the dynamometer processor for each roll(s):

          - wheel speed and accel/decel rate
          - front/rear roll speed and accel/decel rate     (actual and demand)
           (twin roil dynamometer)
          - roll speed and accel/decel rate              (actual and demand)
           (single roll dynamometer)
          - torques                                (actual, demand, and error)
          - horsepowers                            (actual, demand, and error)
          - inertia simulations                       (actual, demflfHit and error)
          -distances                               (roU revolutions pulses)
          - status of roll brake                      (on, off)
          -status of vehicle lift                     (up, down)
          - status of local/remote control              (local, remote)

       The dynamometer system shall log  or store data for later batch transfer as a tab delimited
       text file or in a compatible format to a remote  computer.
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     Specifications for  Electric  Chassis  Dynamometers


3.5    Electric Dynamometer Data Acquisition Package

      Each dynamometer shall be supplied with a separate microcomputer capable of running the
      EPA Video Driver's Aid (VDA) application module and accessing the VDA file server via
      the EOD Laboratory Network System. This microcomputer system shall collect the
      dynamometer speed signals and monitor all other test parameters. The system (or
      equivalent) shall include, at a minimum-

      -One Macintosh ELfx chassis with 6 NuBus slots, 8 MBytes RAM, 210MB internal disk,
        and extended keyboard.
      -One Color monitor 19" or larger diagonal screen at 70-75 pixels per inch, including video
        card(s).
      -One Lab View 2.0 (runtime) or later software to access data from the NuBus hardware.
      -Three NuBus cards from National Instruments
            NB-MIO-16XL18, NB-MIO-16XH18, and NB-DMA2800
      -One NB Series RTSI Bus cable from National Instruments
      -Two SSR (8 module mounting racks) with SC-2050 Adapters and 2 CB-50 Terminal
        Strips
      -One NuBus card to enable Ethernet communications
      -One NuBus card to generate the video signal for a color projector to display the VDA trace
        as a rear screen image from outside the vehicle test celL

      One system shall be used in the instrumented vehicle for the acceptance testing. Therefore,
      it shall be shipped to EPA a minimum of 60 days prior to commencement of contractor
      performance testing.
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     Specifications  for  Electric  Chassis  Dynamometers


4.0   Acceptance Tests. Procedures,  and  CHtfHa.

4.1    General Acceptance Provisions

       The contractor shall complete all performance tests before shipment of the dynamometers)
       to EPA.

       The contractor shall supply complete procedures for performing parasitic loss corrections
       for EPA review before beginning any testing.

       The contractor shall supply all collected data for EPA review before shipment of the
       dynamometers). EPA shall complete all reviews within 15 days of receipt

       EPA shall reserve the right to observe the performance testing at the contractor's facility.
       The contractor shall give the EPA Project Officer a minimum of 15 days written notice prior
       to the start of any performance testing.

       No authorization to ship the dynamometers) shall be made until acceptance of the
       dynamometer's performance is approved by the EPA Project Officer.  The contractor shall
       accept full responsibility for any equipment, supplies, or materials shipped prior to
       Government approval

4.2    Testing Requirements and Overview

       EPA shall reserve the right to waive specific testing if other means or data are available to
       verify the criteria and/or performance.

       Appendix A is a cross reference guide to specific dynamometer requirements and the
       subsequent tests which will be used to verify the requirements.

4.2.1   Reporting

       The contractor shall submit a report to the EPA Project Officer for each dynamometer
       within 30 days of completion of the contractor's performance testing. The report shall
       contain, at a minimum, all information required under Sections 4.2.4 and 4.3, as well as:

       A.    A complete description of all parameters related to and including the raw test data
             collected including:

             1.     Test dates
             2.     Personnel
             3.     Location (test site and dynamometer serial number)
             4.     Ambient conditions (including time of day, barometer, temperature, and
                    humidity)
             5.     Exact tire specification and configuration [tire pressure, tire radii (free-
                    hanging, flat surface, and dynamometer roUer-to-axle center)]
             6      Axle loads (both drive and non-drive)
             7.     Total empty vehicle weight
             8.     Driver weight
             9.     Percent fuel fill and tank capacity (in gallons)
             10.    Vehicle drive axle brake and bearing drag
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     Specifications for  Electric  Chassis  Dynamometers


      B .    A summary table for the testing results (Section 4.4.3.5) indicating all speeds and
            torque measurements and statistics on the repetitive tests.

      C .    All setup parameters used in the configuration of the subject dynamometer to
            perform the requirements of Section 4.0.

      D .    A complete list of all test and signal conditioning equipment, including make, model
            number, resolution, and measurement rates for each parameter.

4.2.2  Vehicle Torque Wheel System

      A vehicle shall be instrumented with torque wheels for the tests in sections 4.4.3.2 thru
      4.4.3.5. The wheel torque measurement system shall have a torque reading resolution of ±
      0.05% of each dead weight data point when calibrated using certified weights (±0.1%
      accurate), traceable to an international standards organization. The dead weight calibration
      shall have uniformly  spaced calibration points from marimnm to minimum and all response
      readings shall deviate less than 0.2% of point for each calibration point (from -100 to +100
      percent of the torque transducer's full scale) for both positive and negative torque
      calibrations. Weights shall be applied both sequentially and in random order as shown in
      the table below, in percent of full scale:
              Positive

           Load        Unload
        zero/shunt
          10%
          20%
          30%
          40%
          50%
          60%
          70%
          80%
          90%
          100%
  100%
   90%
   80%
   70%
   60%
   50%
   40%
   30%
   20%
   10%
zero/shunt
zero/shunt
  -10%
  -20%
  -30%
  •40%
  -50%
  -60%
  -70%
  -80%
  -90%
 -100%
                  Negative

                           Unload
 -100%
  -90%
  -80%
  -70%
  -60%
  -50%
  -40%
  -30%
  -20%
  -10%
zero/shunt
                             Random
   20%
   80%
   30%
zero/shunt
  -80%
  -30%
 -100%
zero/shunt
   10%
   90%
   60%
  -40%
  -10%
  -20%
zero/shunt
   50%
   40%
  1 00%
zero/shunt
  -30%
  -80%
  -90%
      The torque wheel system shall totalize wheel revolutions and vehicle positive and negative
      torque separately, as well as sampling wheel angular speed and torque at least 20 rimes per
      second.

      The speed used for a driver's trace and the speed used for the dynamometer load setting
      control loop shall be synchronized within ±0.1 mph for all required tests.
                                      Page 18
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     Specifications  for  Electric  Chassis Dynamometers
4.2.3  Data Acquisition
       The contractor shall provide a vehicle with a General Motors five lug bolt pattern on the
       wheels (4.5" center-to-center spacing between every other lug nut) to measure and record
       test data using R14 wheels and steel belted radial tires. Test data shall be collected using
       torque wheels and data acquisition equipment supplied by EPA.  EPA will use a Macintosh
       Hx computer with National Instruments 16-bit resolution hardware and Lab VIEW 2.0
       software to acquire all data.

4.2.4  Data Analysis and Presentation

       All testing results shall be supplied with summary tables containing the following, at a
       minimum!

       1 .     Elapsed Time (seconds; xxx.xx)
       2 .     Driver's Trace and Vehicle Speed (mph; xjutx)
       3 .     Wheel Encoder Frequency (Sample Period Hz and Total Counts)
       4 .     Wheel Angular Velocity and Accelerations (mph, mph/sec ; xxxx)
       5 .     * Front Roll Encoder Readings (Sample Period Hz and Total Counts)
       6.     * Front Roll Velocities and Accelerations (mph, mph/sec ; xx.xx)
       7 .     * Rear Roll Encoder Reading (Sample Period Hz and Total Counts)
       8 .     * Rear Roll Velocities and Accelerations (mph, mph/sec; xx.xx)
       9 .     Power Absorption Unit Torque (Ft-Lb; xxxjc)
       1 0.   Power Absorption Unit Horsepower (hp; xx.xx)
       1 1 .   Power Absorption Unit Amperage (Amps; xx.xx)
       1 2.   Vehicle Wheel Torque (Ft-Lb; xxx.x)
       1 3 .   Vehicle Wheel Horsepower (hp; xx.xx)
       1 4.   Drive Trace Roll to Vehicle Drive Wheel Angular Velocity Ratio
       15.   All Dynamometer Settings

       * Note: On a single roll dynamometer, a single roll  reading shall be supplied.

       The specified data for all tests shall be supplied in tab delimited ASCII text files as a
       function of sample collection time, sampled at least 20 times per second. The data may be
       recorded in SI or English units and convened to the  units specified above providing the
       resolution and format of the raw data complies with  the required specifications.

4.3    Component Review and Qalihrarinn Tests

4.3.1  Installation and Mechanical Review

       Typiral installation diagrams and pit cp*^ifirarinns shall hg pmvuierf fnr evaluation  Final
       installation diagrams and pit specifications shall be provided with the requirements of the
       performance data.

4.3.2  Structural and Dimensional Review

4.3.2.1      Frame

       Frame deflection shall not adversely affect dynamometer performance or operation. Front
       and rear roll parallelism and alignment shall not change over the range of test vehicles the
       dynamometer is capable of testing. Engineering data and/or analysis shall be provided to
       document this requirement.


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     Specifications for Electric  Chassis  Dynamometers


4.3.2.2      Bearings and Lubrication

       Motoring torque versus elapsed time data shall be provided to document this characteristic.
       Parasitic losses shall be stable to within ± 0. 1 hp in ten minutes or less at an average speed
       of 50 mph, after the dynamometer is started from a two-hour idle period, with a
       dynamometer enclosure temperature of 70-80 °F. Stabilized bearing friction shall remain
       constant within ± 2% between the dynamometer contractor's recommended calibration
       periods for vehicle test environment temperatures between 0 and 100 °F.  The contractor
       shall include the parasitic calibration frequency per 1000 miles of use needed to eliminate
       changes > 0. 1 hp at 50 mph.

4.3.2.3      Roller Geometry

       The contractor shall document physical measurements that confirm dimensional
       requirements such as diameter, roller set parallelism, roll spacing, and surface finish.
4.3.3  System Operation ?nd ("alifrrarinn Review

       The contractor shall submit, for EPA review, the torque, speed, and acceleration calibration
       procedures as well as the proposed electrical and base mechanical inertia simulation
       verification procedure 15 days before the performance and submission of results from
       calibrations.

4.3.3.1       Mechanical Inertia Determination

       The contractor shall supply a complete summary of all physical components of the
       dynamometer and their individual contribution to total calculated mechanical inertia. The
       description shall include diagrams of physical layout and specific definition of which
       components are inside or outside the dynamometer's control loop.

       The contractor shall provide verification of physical measurements to document that
       components have been built to specification. The total system inertia for each flywheel
       combination shall be verified to ± 0. 15% of stated value.  The total system inertia shall be
       verified through dynamic tests using the dynamometer system.

       The contractor shall submit documentation that the mechanical inertia weights are balanced
       to within the tolerances specified by the balance quality level specified in Section 1.7. The
       documentation shall contain the actual procedure and data or information generated as proof
       of compliance with this requirement.
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     Specifications for Electric  Chassis  Dynamometers
4.3.3.2
Torque Cell Calibration
      The contractor shall provide all measurement data including documentation of the effective
      fixture arm length. The dead weight calibration shall have uniformly spaced calibration
      points from maximum to minimum. All calibration points must be accurate to < ± 0.1 % of
      full scale (FS) for each calibration point (from -100 to +100 percent of the torque
      transducer's FS) for both positive and negative torque calibration weights. Calibration
      weights (± 0.1 % accurate) shall be directly traceable to an international standards
      organization. On both positive and negative torque calibrations, weights shall be applied
      both sequentially and in random order shown in the table below, in percent of full scale.
      The contractor shall supply data to substantiate that the dynamometer torque measuring
      system satisfies the following requirements:
              Positive
           Load

        zero/shunt
          10%
          20%
          30%
          40%
          50%
          60%
          70%
          80%
          90%
          100%
          Unload

          100%
          90%
          80%
          70%
          60%
          50%
          40%
          30%
          20%
          10%
        zero/shunt
zero/shunt
  -10%
  •20%
  -30%
  -40%
  -50%
  -60%
  -70%
  -80%
  -90%
 -100%
      Negative

              Unload
 -100%
  -90%
  -80%
  -70%
  -60%
  -50%
  -40%
  -30%
  -20%
  -10%
zero/shunt
                                                  Random
   20%
   80%
   30%
zero/shunt
  -80%
  -30%
 -100%
zero/shunt
   10%
   90%
   60%
  -40%
  -1 0%
  -20% •
zero/shunt
   50%
   40%
  1 00%
zero/shunt
  -30%
  -80%
  -90%
4.3.3.3
             Hysteresis
             Repeatability
             Non-Linearity
             Zero and Shunt Drift
             Rise Time to 90% of Load
             Time Constant

Toraue Transducer Virtual Snan & Zero
                                                  ±0.1% of full scale
                                                  ±0.05% of full scale
                                                  ±0.1% of full scale
                                                  ±0.1% over 24 hours
                                                  < 10
                                                  < 50 milliseconds
Dynamometer controller software calculations may be used to minimize torque transducer/signal
conditioning drift The following equations describe this software technique. Other methods may
be described or proposed if shown to produce comparable results. If the contractor utilizes any of
these techniques, test data shall be provided to verify the accurate performance.
                        Vm(G)
                                            B
                         where:
                               V.  = Corrected Output

                               V  = Measured Output
                                 m             T
                                      Page 21
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     Specifications for Electric  Chassis  Dynamometers
                                G  =
                                     
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     Specifications for  Electric  Chassis  Dynamometers


       A maximum shock loading test shall be performed, to establish the structural integrity of all
       system components.  This test sequence shall consist of:

       1.     The dynamometer, set at its base inertia weight, shall motor itself from 0 to 60 mph
             at the maximum motor hp and the emergency stop shall be activated to decelerate the
             dynamometer to zero mph five consecutive times within one half hour.

       Immediately followed by:

       2.     A vehicle shall be properly positioned and normally restrained on the dynamometer.
             The vehicle shall be operated at wide open throttle for approximately five seconds,
             then the vehicle brakes locked for approximately one second (until the driver's trace
             speed decreases discernibly). This sequence shall be repeated until the vehicle's
             speed reaches 60 mph.

4.4.2  Electrical Inertia Simulation Response

       Simulation response shall be reported as the dynamometer torque response to a simulated
       step change in speed signal The response definitions are contained and illustrated in
       Appendices E and F. The inertia settings shall be base mechanical inertia, 2,000 and 5,500
       Ibs. Six mph/sec and 0.5 mph/sec acceleration and deceleration sawtooth profiles and
       square wave steady speeds shall be simulated using a signal generator.

       Response time in all cases shall be less than 100 milliseconds.

4.4.3  Operational Response Characterization

4.4.3.1      Dynamometer Self-motoring
             The following tests shall be performed before shipment.

   A.  Parasitic Losses Determinations and Stability:
       The dynamometer shall assess and compensate for the vehicle loads that are attributable to
       tire/roller and dynamometer mechanical parasitic losses. The following tests are designed
       to simulate daily use and subsequent stability of the dynamometer parasitic losses.

       The subject dynamometer shall perform coastdowns (with and without a vehicle), with all
       dynamometer load coefficients set at zero, and calculate the equation of parasitic losses
       (Ibs. force) from 60 to 10 mph. The dynamometer shall accept a target total vehicle road
       load curve and r^Vp"toff the required coefficients necessary to match the vehicle load curve
       and compensate for the previously calculated parasitic losses.

       Once the dynamometer has been warmed according to the contractor's published
       procedure, the dynamometer shall perform a no load coastdown (at dynamometer base
       inertia weight) and rai^niqw the coefficients to describe die parasitic losses.
       An assessment of the parasitic friction transient behavior shall be performed The
       dynamometer shall be allowed to sit for a minimum of two hours. The dynamometer shall
       then motor itself through a series of steady speeds each 30-seconds in duration, at 10, 20,
       30, 40, 50, and 60 mph, followed by a no load neutral coastdown from 65 to 10 mph. The
       steady state/coastdown sequence shall be repeated for a total of five sequences performed
       within one hour.

       NOTE:  If the coastdown exceeds five minutes with no electrical load, a constant electrical
       force may be applied to limit the coastdown to five minutes.
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  Specifications for  Electric  Chassis  Dynamometers
   On the final sequence following the 60 tnph steady state, the dynamometer shall motor
   itself to 80 mph within ten seconds and maintain this speed for 30 seconds prior to the no
   load neutral coastdown.

   The data supplied shall verify all coastdown calculation capabilities.

B. Steady State Verification of Parasitic Friction Stability:

   The measured steady state horsepower values after ten minutes shall be within ± 0. Ihp of
   the stabilized values, calculated using the dynamometer-produced parasitic loss equation.

C. Mechanical Base Inertia Verification:

   The dynamometer shall be programmed to operate at its base inertia weight (Base inertia
   shall be defined as the inertia weight with no electrical or incremental mechanical inertia
   engaged.)  Using a constant acceleration rate the dynamometer shall accelerate to 65 mph
   and then decelerate at the same rate to 0 mph. The collected force data shall be corrected for
   the parasitic forces and then used to verify the mechanical base inertia by the following
   equation:


                       Force     = (— ) a
                                   vg'

          where:
                       W        = Base Inertia Weight (Ibs)
                       g         = Gravitational Constant (32. 17 ft/sec2)
                       a         = Accel/Deed Rate

          combining with g produces the following calculated inertia equation:

                                 = F / 0.045585(dV/dt)m
          where:
                                 = CalCTitosqd Mechanical Inertia Weight (Ibs.)
                                 = Sample Interval Net Roller Surface Force
                                   Measured by Dynamometer (Ibs.)
                                 3 Measured Interval Acceleration (mph/sec)

   The accel/decel procedure shall be repeated five times at rates of 1, 3, and 6 mpn/second or
   whichever of these rates the dynamometer can achieve, as well as the maximum
   dynamometer motoring horsepower.

   The avenge value of Wcafced at each accel and deccl rate shall be within ± 0.2% of the
   contractor's specified Base Inertia Weight. These tests shall be applied to verify the
   incremental trtf^^m"!^! Jivcr"3 values available.
                                     Page 24            	6/5/91   4:50 PM

-------
  Specifications  for  Electric  Chassis  Dynamometers


D. Verification of Friction Compensation:

   Friction compensation accuracy shall be checked with a warmed dynamometer and all road-load
   simulation coefficients (F = A + BV + CW) set to zero for each of three separate inertia weight
   settings (Base Inertia Weight, 2000 Ibs., and 5500 Ibs.).  After motoring to 50 mph, the
   dynamometer shall be switched to road simulation mode and shall compensate for all parasitic
   losses. Speed drift versus time shall be used to determine the compensation error.

                ferror = compensation error Obs) = m (AV) (0.045585VAt
                     where:   m    = actual inertia
                             A V  = speed drift (mph)

                             At   = time over speed change (sec)

   In addition, the friction compensation accuracy shall be recorded at  steady speeds of 10.
   20, 30,40, and 60 mph for each of the above inertia settings.

   The compensation error at each speed shall not exceed the equivalent of ± 0.1 hp at any
   steady state speed.

E. Road-Load Curve Simulation and Repeatability:

   Accuracy and repeatability of the road load curve shall be determined from five separate 65
   to 10 mph continuous neutral coastdown tests (without a vehicle) at each load setting from
   below. Coastdown force shall be determined at speeds of 60,  SO, 40, 30, 20, and 10 mph.
   The error (e0 at each coastdown point is the difference between the calculated force and the
   measured coastdown force:

                       _         — B       P
                       °i        ~ r calced" rm
                      Fcatei

                      Fm       =(0.045585) (I) (dV/dt)

          where:
                      dV/dt     = Measured (or calculated) Sample Interval
                                  Acceleration (20 samples/sec sampling rate)
                      I         » Inertia weight setting Obs)

   The following road-load horsepower and inertia conditions shall be measured:

          DYNAMOMETER BASE INERTIA
          A » B = C =4)              and I = Dynamometer Base Inertia

          LDV MINIMUM
          A = 26.25 lb., B = C = 0,   and I =  2,000 Ib.

          LDV MAXIMUM
          A = 187.5 lb., B = C = 0,   and I»  5,500 lb.
                                    Page 25	6/5/91   4:50 PM

-------
     Specifications for  Electric  Chassis  Dynamometers


      . Accuracy shall be defined as the average force error.  Repeatability shall be defined as two
       times the standard deviation, for each speed point

       Coastdown accuracy and repeatability versus speed shall be documented for the minimum
       and maximum force curves and shall not be significantly different, at a 90% statistical
       confidence level, from the subject dynamometer's own accuracy and repeatability at its base
       mechanical inertia weight setting.

4.4.3.2      Steady State Speed Loading
             This shall be performed before shipment, with a vehicle.

       The stabilized dynamometer shall be programmed with two loading curves (see Appendix
       B Figure 2).  The contractor shall perform steady state tests ranging from 10 to 60 mph in
       five mph increments. Each shall be of 30 seconds duration, (ascending or descending
       order) for each dynamometer load set curve.  Five replicates of each run shall be recorded.
       All load setting and driver's trace speed signals shall remain within ±0.1 mph during the
       data recording periods.

       The dynamometer and vehicle wheel force data from each steady state/speed shall be
       graphed versus speed (mph). The dynamometer force data from five runs shall be within
       ± 1 % of a curve of the mean values (from 10 to 60 mph) for the five replicate runs.  The
       mean values for each speed increment shall be calculated by the formula in the example at
       the end of this section. The data shall be graphed in the same manner as shown in
       Appendix C, Figure 4.

4.4.3.3      Fixed Acceleration Rate
             This shall be performed before shipment, with a vehicle.

       The dynamometer shall compensate for all dynamometer and vehicle tire/roll interface
       parasitic losses (i. e., the measured wheel uxque, at steady state speeds, shall equal 0).
       The vehicle shall accelerate the dynamometer for 2000 and 5500 pound inertia weight
       settings. The contractor shall perform acceleration test sequence.* for 1, 3, and 6 mph/sec
       accelerations from 0 to 60 mph.  The sequences shall consist of one run per acceleration
       rate and inertia setting (six runs).

       The dynamometer roller force and vehicle wheel force data from each acceleration shall be
       graphed versus the dynamometer acceleration rate (dV/dt). Ail dynamometer roller force
       data shall be  within ± 1 % of a curve of the calculated force values versus acceleration rate.
                                         Page 26                      6/5/91    4:50 PM

-------
     Specifications  for Electric  Chassis  Dynamometers


       The vehicle wheel force data shall not exhibit a variability greater than that exhibited for the
       same acceleration rates performed under test track conditions.  Each ideal inertial
       acceleration force value shall be calculated by the following formula:
                                     = M^t (0.045585)(dV/dt)
             where:
                                     = Calculated Instantaneous Force (Ibs.)
                           M«a      = Set Inertia Weight flbs.)
                           dV/dt      = Measured (or calculated) Sample Interval Acceleration
                                      (at 20 samples/sec sampling rate)

       See Appendix C Figure 3 for an example of how the data shall be graphed.
4.4.3.4      Neutral Coastdown Rolling 1
             This shall be performed before shipment, with a vehicle.

       The contractor shall perform neutral coastdown tests from 65 to 10 mph consisting of five
       replicate runs per inertia weight using the load curves and inertia weights (2000 and 5500)
       used in Sections 4.4.3.2 and 4.4.3.3.

       The dynamometer and vehicle wheel force data shall be graphed versus dynamometer
       speed. The dynamometer roller force data shall be within ± 1 %of a curve of the mean
       values (from 60 to 10 mph) for the five runs. The data shall be graphed in the same
       manner as in Appendix C, Figure 4.

4.4.3.5      Urban  Dynamometer Driving Schedule fUDDS-505 seconds)
             This shall be performed before and after shipment, with a vehicle.

       Testing at the contractor's facility shall consist of the collection of the same data on each
       dynamometer  which the contractor shall deliver under this contract. Each set of 4WD
       dynamometer  roll(s) shall be tested in the 2WD dynamometer configuration.

       The testing shall be conducted on a dynamometer with a vehicle using load curves and a
       test inertia weight specified by EPA. A minimum of five sequential UDDS - 505 tests shall
       be run for each test specified.

       The data required under Sections 4.2.1 and 4.2.4 shall be logged at a sample rate of 20Hz
       and stored in a disk file by the system computer for the first 505 seconds of the UDDS.

       The collected data shall be supplied to EPA for review and evaluation.  Statistical analysis
       of the replicate tests shall be performed by EPA to quantify the performance characteristics
       of the dynamometer/vehicle system operating under transient driving schedules.  The
       contractor shall correct all performance deficiencies that are found to be statistically
       significant relative to the other dynamometers produced and tested.

       Real Time Performance Monitor

       The dynamometer controller software shall perform the following analysis of the force
       error profile. Statistics on the values of the force error versus reference force and velocity
       shall be generated.  The dynamometer software shall report the minimum, maximum,
       average, standard deviation, and number of values collected for the force error for each ten
       mph speed interval during the test phase. The contractor shall state the calculation
       frequency and cutoff speed used for data acquisition. This technique shall be used to
       monitor all tests.
                              	Page 27	         6/5/91   4:50 PM

-------
Specifications for Electric  Chassis Dynamometers
 System performance shall be verified through the analysis of the force error signal The
 equation for the force error signal is as follows:

                   Em   =100*(Fm-Fr)/Fr


                      where:
                            Em  = Force Error Signal
                            Fm  = Measured Force
                            Fr  = Reference Force

 Measurements shall be made during each vehicle UDDS • 505 seconds sequence performed
 in this section.

 The average force error signal over the UDDS - 505 seconds shall be within ± 1% o"cr the
 entire speed range.
                               Page 28	6/5/91   4:50 PM

-------
3.
4.
                                                Appendix A
              Electric  Dyno Acceptance  Cross  Reference
Ambient Conditions Operation
a.   Narrative
Wheel Base Adjustment
a.   Within ±0.08'
Roll Balance
IW Determination
                                      3.
                                     4.
                                      5.
Speed Measurement Accuracy
 a. ± 0.0.5 MPH
Acceleration Measurement
a.  0-10 MPH/see Range
b.  t 0.01 MPH/sec Accuracy
Elapsed Tune
a.  ±0.01 seconds
Torque
a.  ± 0.2 ft-Mrain 1000 samples/sec)
b.  ±0.1% hysteresis
c.  ±0.1% zero shunt drift
d.  ±0.1% Repeatability
   ±0.1% Linearity
                                      e.
                                      ResponM
                                      a.  < 100 msec to 90%
1. Align Vehicle Procedure
2. Warm-Up
3. Coastdown/Acceleration
  a. Any from 010 10 MPH/sec
     OR Max Avail power
     (1.3.6 MPH/sec Accels)
  b. Base Inertia Verification
4. From Panel by Operator
5. Steady Stales Parasitic Losses Stability
   a.  Shall remain < 10.1 HP (ALL Speeds)
                               Tests Performed With a Vehicle
1. Inertia Simulation
  a.  Parasitic Losses Compensated
  b.  2000 & 5500 Ibs IW
     ( 1. 3.6 MPH/sec)
  c.  M»F/(dV/dt)
2. Acceleration Me
  a. Include Zero
  b. Within 1001
3. Response
  a. < 100 millisec lag to 90%
                                         1. Road Load Simulation Accuracy
                                           a. Repeauole ± 1%
                                         2, Access coefficients within
                                           10
                                         1. Rofl Synchronization
                                           ±0.1 MPH ALL Tests
                                         2. Restraint System
                                     1. Road Load plus Inertia Simulation
                                      a. ±1% of Value Set
                                     1 Max Velocity 80 MPH
                                     3. Min Velocity   5 MPH
                                     4. Min Interval 3 MPH
                                     5. Data Display
                                       a. Upper A Lower Speeds of Range
                                         and Interval
                                       b. Elapsed Tune
                                       c. Caked Coeffieats
                                       d. Actual Power Absorbed
                                          1. Test Distance
                                             a. ±1 Point in 2000
                                          2. Positive Load Repeatability
                                          3. Negative Load Repeatability
                                          4. Error Signal Verification

-------
           Appendix B • Figure 1   Dynamometer
           Response Rise and Settling Time Illustration
Rise Time
                •Settling Ti
                              Elapsed Time
          Appendix B • Figure 2
          Steady State Dynamometer Load Curves
 J3
t in.
100-
90.
80.
70.
60
50
40
30









	 • 	 '







^

9^






X
V
s






/,
V
f





>

/





J
/
/






//
Y








                                                     • Dynamometer Load Curve #1
                                                      F = 39.504 + 0.11258V * 1.5581e-2V*2
• Dynamometer Load Curve #2
 F = 26.752 - 6.1254*-5V * 22903e-2V*2
                           Speed(MPH)

-------
        Appendix C -  Figure 3
        Force  verses Acceleration  (dV/dt)
e
a
o
    Ideal Calculated Force (Set Inertia Weight)
• "^™"  -1% Minimum Limit
     +1% Maximum Limit
         Actual Measured Force
                          dV/dt
        Appendix C  - Figure 4
        Example of Mean Force Value Graphs
   V)
   I.
   4)
   
-------
                                  Appendix D
                 Symbols  and  Specification Terminology
SYMBOLS

    A
    a
    B
    b
    C
    c
    D
    F
    FE
   FEF
    g

    M
    n
    P
    r2
    S
   sin 9
    t
    dt
    At
    V
    VE
    dV
    DV
    W
    0)
   dV/di
   du/dt
                                                     UNITS
Constant rolling resistance parameter
Constant friction characteristic
Speed proportional rolling resistance parameter
Speed proportional friction characteristic
Speed squared (wind) resistance parameter
Speed squared friction characteristic
Parameter for braking and miscellaneous forces
Thrust parallel to road or tangential to roll
Force Error
Force error fraction
Gravitational acceleration
Effective mass
Number of data points
Power transmitted through roll surface
Regression coefficient
Distance roll surface moved since distance counter reset
Sine of hill angle above (+) or below (-) horizontal
Time
Derivative of time
Finite time interval
Speed over road or roll surface
Speed error
Derivative of speed
Finite change of speed
Gross weight of vehicle including passengers
Angular velocity
Linear acceleration
Angular acceleration
           N, Ib
           N, Ib
       N/kph, Ib/mph
       N/kph, Ib/mph
    N/(kph)2, lb/(mph)2
    N/(kph)2, lb/(mph)2
       dimensionless
           N, Ib
           N, Ib
       dimensionless
9.807 m/sec2 or 35.32 kph/sec
32.17 ft/sec2 or 21.93 mph/see
           N, Ib
          kW.hp
       dimensionless
           m, ft
       dimensionless
            sec
            sec
         kph, mph
         kph, mph
         kph, mph
         kph, mph
           N, Ib
          rads/sec
       m/sec2, ft/sec2
         rads/sec2
Subscripts
     a
     c
     d
     g
     i
    m
     o
     R
 1, 1-2, 2-3
Average
Device which provides load in a complex chassis roll system
Correction for gravitational and engineering units:
Multiplied by 35.31 kph/sec in SI
OR
Multiplied by 21.93 mph/sec in Imperial system
Inside control loop
Measured
Outside control loop
Road equivalent
From point 1, 1 to 2, 2 to 3, etc.

-------
                                    Appendix  E

               Glossary  of  Acceptance  Criteria Terminology
Overshoot
Percent Overshoot
Delay Time


Rise Time (Tr)



Settling Time (Ts)




Time Constant (t)



Transport Lag (Tj)


Reaction Tune
Response Tune
The overshoot is the maximum difference between the transient
and steady-state output of a system in response to a unit step
input. Overshoot is a measure of relative stability and is often
represented as a percentage of the final value of the steady-state
output
  where:
          ss
                                           peak value

                                           steady state or final value of c(t)
The time delay is defined as the time required for the response to a
unit step function input to reach 50 percent of the final value.

The rise time is customarily defined as the time required for the
response to a unit-step function input to rise from 10 to 90 percent
of the final value.

The settling time is defined as the time required for the response to
a unit-step function input to reach and remain within a specified
percentage (frequently 2 to 5 percent) of its final value.

The predominant time constant is an alternative measure of settling
rime.  The envelope of the transient response decays to 37 percent
of its initial value in t seconds.

The transport lag is the delay in the onset of a change in feedback
as a response to a change in system output
The system reaction nmg j$ defined as the minimum rime lag
between an input change and the resultant change in system output
and is the direct summation of the unrelated, forward transport
lags in the system. Reaction time is sometimes incorrectly
referred to as Response Time.

The response time is defined as the lag between an input change
and the time the response rises to 90 percent of the final value.

-------
     RESPONSE CHARACTERISTICS OF A SECOND ORDER SYSTEM TO A UNIT STEP FUNCTION
      Overshoot
Unit step input
       Response tune
System reaction lime
Cftponentu!
envelope of
the transient
response
                                        Rise unit   I uiie constant
                                                                                                             TJ
                                                                                                             •o
                                                                                                             A
                                                                                                             a
                                                                                                             a.
                               DcUy in i ic
            Stilling nine u> wnliin

            t K% of dual value

            »•-- 2'Jt 01 *»%

-------
                 Engineering   Operations   Division   Test   Procedures

                                         Gas Laboratory
Col A     Col B
	     	    TP 101   Preparation of Gravimetric Binary  Gas Mixtures
	     	    TP 105A  Gas  Naming
	     	    TP 403   Gas  Correlation
	     	    TP 502   Gas  Cylinder Change
                                      Chemistry  Laboratory
	     	    TP 106B  Analysis  of Alcohols Extracted from Gasoline
	     	    TP 108A  Vapor  Pressure of Gasoline and Gasoline-Oxygenate Blends
	     	    TP 109   Test for  Lead-in-Gasoline by Atomic Absorption Spectrometry
                                   Calibration  and Verification
	     	    TP 202   Dynamometer Calibration - Frictional Horsepower
	     	    TP 204   Gas  Analyzer Calibration Curve Generation
	     	    TP 205   Span Point Change Notice
	     	    TP 207A  Dynamometer Calibration - Road Load Power Control Electronics
	     	    TP 210   Critical  Flow Orifice Calibration
	     	    TP 211   Calibration, Operational Verification, and Preventive Maintenance of the
                            Leeds  and Northrup Ambient Temperature Monitoring System
	     	    TP 213A  Calibration and Verification of Digital Barometers
	     	    TP 214   Calibration, Operational Verification, and Preventive Maintenance of General
                            Eastern Dew-point Meters
	     	    TP 215   Dry  Gas Meter Calibration
	     	    TP 302A  Dynamometer Calibration Verification
	     	    TP 303   Analyzer  Monthly Curve Verification
                                   Vehicle  Emission Laboratory
	     	    TP 701B  Vehicle Inspection and Acceptance
	     	    TP 702D  Vehicle Fuel Exchange
	     	    TP 703C  Vehicle Preconditioning (Video Drivers Aid)
	     	    TP 704C  Diurnal Heat Build  (No Evap)  Test
	     	    TP 705B  Diurnal Evaporative Emission (Heat Build) Test
	     	    TP 707C  Sample Collection of the Urban Dynamometer Exhaust Emission Test  (Video
                            Drivers Aid)
	     	    TP 708C  Sample Analysis of the Urban Dynamometer Exhaust Emission Test
	     	    TP 709C  Hot  Soak  Evaporative Emission Test
	     	    TP 710B  Sample Collection of the Highway Fuel Economy Test (Video Drivers Aid)
	     	    TP 711A  Sample Analysis of the Highway Fuel Economy Test
	     	    TP 712A  Quick  Check Coastdown
	     	    TP 713B  Sample Collection, Continuous Hydrocarbon Analysis,  and Particulate
                            Collection of the Light Duty Diesel Test
	     	    TP 714A  Diesel Particulate Filter Handling and Weighing
      Please   complete  the   back   section  before   returning   this   form

-------
 Engineering  Operations  Division  Procedure  Documentation  Request


Please type or  clearly print your name, mailing address, and business phone  number in
the  area provided below.


Please  register my  name  on  the Quality  Control  External Mailing.  I  wish  to
receive  future  documentation  for  the  procedures  checked  on  the  front  of
this form.


     Name:      	


     Address:  	
     Phone:     Area Code  (

-------
       >*
             UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                            ANN ARBOR. MICHIGAN  48105
                                May 23, 1986
                                                                     OFFICE OF
                                                                  AIR AND RADIATION
SUBJECT: Calibration and Maintenance Services

FROK:
TO:
David W.  Perkins,  Supervisor
Calibration and Kaintenance Group

James D.  Carpenter,  Chief
Facility  Support Branch
    Attached  is  a  summary  of  the  services  currently  provided  by  the  Gas
Analysis Lab.  It  covers  the service,  tolerances,  frequency and it identifys
the group to whom these  services are provided.

    Also attached,  are updated versions of diagnostic and  other  test equipment
checks performed  by the  Calibration and Kaintenance Group.

    If you have any questions or comments please contact me.
Attachments

-------
                                              GAS LAB SERVICES
      AREA
Provide NBS and  Gravimebric  standards


Provide Secondary  standards



Provide working  gasea

Provide specialty  gases

Provide pure propane for CFO Kits

Provide FID fuels

Provide N2



Provide zero grade air
 FREQUENCY

2 years or
as required

Renamed every
year or as
required

As required

As required

As required

As required

As required
As required
  TOLERANCE
±0.52


±0.3*



+1.0%



less than 0.5$ contamination

+2% of 40-60# blend

less than 1 ppmC hydrocarbon,
1 ppm CO, 400 ppm C02 and
0.1 ppm NO contamination

18 - 2\% 02,less than 1 ppmC
hydrocarbons, 10 ppm CO, 400 ppm
C02 and 0.1 ppm NO contamination
GROUP COVERED

  TPB, TEB(EOD),
  SDSB(HD)

-------
                                                                                                           -2-
      AREA
Test Equipment Checks

           FREQUENCY
I.    Analysis System Checks

      A.  Blended Cas
          Cross-check Bag (SAC)
              Daily
      B.   CH^ Sample Correlation
      C.   NOx Analyzer Converter
          Efficiency Check
      D.   NO/NOx Flow Balance
          1.   Check the NO and NOx response
            with a known .concentration of
            NO/NOx

      E.   CH4 Peaking and Characterization
          1.   CH4 SAE procedure J-1151A
             2 Weeks
             Weekly
             4 months
             3 months
Analysis Systems

      TOLERANCE
GROUP COVERED
   Response based on standard
   deviation (sigma) levels
   listed in QC comments.
   Includes all laboratory
   analysis sites.
   Any reading outside of 3
   sigma - immediate shut down.
   Rerun of analyzers affected
   after repair.
   Two of three readings outside
   of 2 sigma - Investigate within
   1-2 days.  Rerun of analyzers
   affected after repair.
   Four of five reading outside of
   1 sigma - Investigate within
   3-4 days.  Rerun of analyzers
   affected after repair.
   Trends or biases - investigated
   as time permits and at scheduled
   monthly curve verifications.

   Response based on the criterion
   listed above.
  TPB
       minimum conversion of-
   N02 to NO.  Investigation
   required below 95$ level.
   NO should read
   less than NOx,
   +1 ppm from tag


   Outlined in procedure
  TPB,  TEB (E&D),
  SDSB  (HD)
  TPB,  TEB  (E«D)
    SDSP (HD)

-------
                                                                                                          -4-
      AREA
TEST EQUIPMENT CHECKS - Analyzers

         FREQUENCY           TOLERANCE
II.   Analyzers
      A.  HC
          1.  Calibration Gases

              a.  Zero - HC free air
              b.  Major - Air
              c.  Minor -

          2.  Types of PIDs

              a.  Cold PIDs
                  l) Bag Measurement
                  2) SHED Measurement
              b.  Heated FIDs
                  l) Diesel Measurement

          3.  Types of Fuels
    a.  H2/N2 Bag
    b.  H2/He Diesel & SHED

4.  Flow

    a.  4 scfh bypass

5.  Verifications


6.  New Curves
                                                 Monthly
                                                 As needed
                        Per Proc. 303
                        Per Proc. 204 A1
  GROUP COVERED
                                                   TPB, TEB (E&D),
                                                   SDSB (HD)
                                                   TPB, TEB (BSD),
                                                   SDSB (HD)
                                                   TPB,  TEB (E«D),
                                                   SDSB (HD)
                                                                                           TPB, TEB (E«D),
                                                                                           SDSB (HD)
TPB, TEB (BAD),
SDSB (HD)

TPB, TEB (E*D),
SDSB (HD)
1.  Per final draft issued 6/1/82.

-------
                                         TEST EQUIPMENT CHECKS - Analyzers
                                                                                                           -5-
       ARFA
                                        FREQUENCY
     TOLERANCE
GROUP COVERED
               a.   Curve  Fit Deviations^
               b.   Degree  of Fit
               c.   Number  of data  points

               Special  checks
               a.   Methane Response
      B.  C02

          1.  Calibration Gases

              a.  Zero - N2
              b.  Major - N2
              c.  Minor - C02

          2.  Optical Filter
3.
4.
              a.

              Cell Length

              a.  0.3 inch

              Flow
                                       Monthly
                                                      Secondaries +1% of point.
                                                      On-line working gas + \%
                                                      of Nominal concentration
                                                      Ave. Dev +0.5% of point
                                                      3rd
                                                      7 or more including zero.
1.10 to 1.20?
TPB, TEB (E&D),
SDSB (HD)
                                                                                    TPB,  TEB  (BSD),
                                                                                    SDSB  (HD)
                                                                                    TPB, TEB  (BSD),
                                                                                    SDSB (HD)
                             TPB, TEB (E&D),
                             SDSB (HD)
                             TPB, TEB (ESD),
                             SDSB (HD)
2.  In special  cases or ranges tolerances can exceed  these limits, but still meet Federal Register  tolerances on
non-certification sites.
3.  Ratio of the response to a 50 ppm CH^ cylinder.  	Response in C^Hfl x .3	
                                                             C}?4 Concentration of the cylinder

-------
                                                                                                           -6-
      AREA
           5.  Verifications


           6.   New Curves

               a.   Curve Fit Deviations^
               b.   Degree  of Pit
               c.   Number  of data  points
               d.   Nonlinearity

          7.   Special  C(>2 Curves
               Monthly  Updates*

          CO  (LCD  & HCO)

          1.   Calibration Gases

               a.   Zero -  N2
               b.   Major - N2
               c.   Minor - CC-2

          2.   Optical  Filters

               a.   HCO  (MSA)
                   1)   CaF2
               b.   LCO  (Bendix)
                   l)   Optical and Band
                       Pass Filter
TEST EQUIPMENT CHECKS - Analyzers

         FREQUENCY           TOLERANCE
         Monthly
         As needed
         As needed
Per Proc. 303
Per Proc. 204A1

Secondaries +1% of point.
On-line working gas +_ 1$
of Nominal concentration
Ave. Dev K).5^ of point
3rd
9 or more including zero.
Less than 15.0$

•••0.1 defections
  GROUP COVERED

  TPB, TEB (ESD),
  SDSB (HD)

  TPB, TEB (E«D),
  SDSB (HD)
TPB
                                                     TPB, TEB (BSD),
                                                     SDSB (HD)
                                                     TPB, TEB (ESD),
                                                     SDSB (HD)
1.  Per final draft issued 6/1/82.
2.  In  special  cases or ranges tolerances  can  exceed  these limits,  but still meet Federal Register tolerances on
non-certification sites.
4.  Per EPCN No. 046 4/2/82

-------
       AREA
TEST EQUIPMENT CHECKS - Analyzers

         FREQUENCY           TOLERANCE
                                                                                                           -7-
GROUP COVERED
           3.  Cell Length

               a.  HCO (MSA)
                   1)  3.5 inch
               b.  LCD (Bendix)
                   l)  11 1/8 inch

           4.  Flow

               a.  6 ecfh (HCO & LCO)

           5. Verifications


           6.  New Curves

               a.  Curve  Fit Deviations^
               b.   Degree of Fit
               c.   Number of data points
               d.   Nonlinearity
                   HCO * LCO
       D.   NOx
           1.   Gases
               a.   Zero -  HC  free  air
               b.   Major - N2
               c.   Minor - NO
         Monthly        Per Proc. 303
         As needed      Per Proc. 204A1

           	         Secondaries +1% of point.
                       On-line working gas +_ 1%
                       of Nominal concentration
                       Ave. Dev +0.5$ of point
                       9 or more including zero.

                       Less than 15.0$
                                                     TPB, TEB (BSD),
                                                     SDSB (HD)
                                                     TPB, TEB (BSD),
                                                     SDSB (HD)
TPB, TEB (E&D),
SDSB (HD)

TPB, TEB (E
-------
       AREA
           2.   Plow

               a.   2.0 1pm

           3. Verifications

           4.   New  Curves


               a.   Curve Fit  Deviations^
              b.   Degree  of Pit
              c.   Number  of data  points

      E.  CH4

          1.  Gases

              a.   Zero -  HC free  air
              b.   Major - Air
              c.   Minor - CJfy

          2.  Fuel

              a. H2/He

          3.  Flow

              a.   3.5 scfh

          4. Verifications
TEST EQUIPMENT CHECKS - Analyzers

         FREQUENCY           TOLERANCE
          Monthly

          As needed
Per Proc. 303

Per Proc. 204A1
                        Secondaries +1% of point.
                        On-line working gas +_ \%
                        of Nominal concentration
                        Ave.  Dev +0.5# of point
                        2nd
                        7 or  more including zero.
                                                                                                           -8-
                              GROUP COVERED

                              TPB,  TEB  (E*D),
                              SDSB  (HD)
TPB, TEB (E&D),
SDSB (HD)
TPB, TEB (E&D),
SDSB (HD)
                                                     TPB, TEB (E«D),
                                                     SDSB (HD)
          Monthly
Per Proc. 303
                                                     TPB, TEB (E
-------
                                                                                                           -9-
                                       Test Equipment Checks - Analyzers

      AREA                                       FREQUENCY           TOLERANCE    ,              GROUP COVERED
          5.  New  Curves                          As needed     Per Proc. 204A1               TPB,  TEB (E&D),
                                                                                              SDSB  (HD)
              a.   Curve Fit Deviations2            	         Secondaries +1# of point.
                                                                On-line working gas +_ 1%
                                                                of Nominal concentration
                                                                Ave. Dev +0.5% of point
              b.   Degree of Fit                    	         2nd
              c.   Number of data points            	         7 or more including zero.
1.  Per final draft issued 6/1/82.
2.  In  special  cases or ranges tolerances can exceed  these limits, but  still meet  Federal Register  tolerances
on non-certification sites.

-------
                                   Test Equipment Checks - VAST Diesel Site
                                                                                                          -10-
      AREA
FREQUENCY
TOLERANCE
GROUP COVERED
III.    VAST Diesel Site

      A.  Blower (over Room 532)
        1.  Check oil level
      B.  Pump Operation
        1.  Check sample and fluid
            pump operation
   Weekly
   Weekly
      C.  Bulk Stream Filter
        1.  Check the differential pressure    Weekly
            across the filter on the 700 cfm
            range

      D.  A004 Operation
        1.  Check A004 zero, span, sample      Weekly

      E.  A016 Operation
        1.  Check A016 zero, span, sample      Weekly

      F.  Temperatures and Oven
        1.  Check the system temperatures      Weekly

      G.  Tunnel Inspection
        1.  Visually inspect the tunnel        6  Months

      D.  Motors on Pumps  and Circulators
        1.  Oil each motor and pump bearing    3  Months

      E.  Meter Calibration
        1.  Check fuel dispensed with          6  Months
            5-gallon standard

      F.  Temperature Calibration
        1.  Check fuel temperature with        6  Months
            temperature standard
 Add or change
 as needed
                    Less  than  6" 1^0 drop
                    +0.2  deflection


                    +0.2  deflection


                    As  posted


                    Clean as needed
                    + 0.1 gal
                    + 2°F
   TPB
                               TPB
                               TPB
                               TPB
                               TPB
                               TPB
                               TPB
                                                   TPB
                               TPB
                               TPB

-------
                              Test Equipment Checks - VAST Diesel Site
                                                                                                    -11-
AREA
FREQUENCY
TOLERANCE
G.  Fuel Filters
  1.  Replace filters in dispenser       6 Months

H.  Process Fluid
  1.  Check level                        6 Months
  2.  Check inhibitor level in fluid     Yearly

I.  Process Tank Bottoms
  1.  Draw off sediment from four        Yearly
      process tank bottoms

J.  Liquid Hydrocarbon Detectors
  1.  Calibrate and test for proper      Yearly
      operation

K.  Diesel Particulate Dry Gas
    Meter Calibration
  1.  Verification                       Monthly
                    1/2  to 7/8 full
                   +0.5# Dev. from best fit
                   line.  Slope +0.5^ from
                   active slope.
GROUP COVERED
                                                   TPB
                               TPB
                                                   TPB
                                                   TPB
                               TPB, TEB (E&D)
  2.  Tylan Adjustment
   As needed
                               TPB

-------
                                                                                                     -3-
                               Test Equipment Checks - Analysis Systems

AREA                                     FREQUENCY           TOLERANCE                  GROUP COVERED
F.  CO Analyzer H20/C02 Interference
    1.  Injec.t'3$ C02 bubbled through       Yearly        Federal Register                TPB,  TEB (E&D)
        room temperature water using                      tolerance = + \%                SDSB  (HD)
        the LCO and HCO analyzers                         of full scale" or +3 ppm
                                                          on ranges below 300 ppm

G.  Replace FID batteries                   Yearly               	                   TPB,  TEB (E«D),
                                                                                          SDSB  (HD)

-------
                                                                                                           -12-
                                         Test Equipment  Checks  - Alarms


       AREA                                       FREQUENCY           TOLERANCE                GROUP COVERED
IV.   Alarms
      A.  Toxic Gas Warning System
        1.  Force cal and sample 50 ppm           Weekly            +_ 5 ppm                  TPB,  TEB (E#D)
            CO check one site                                                                SDSB (HD)
        2.  Sample a bag of 25 ppm NOx and        6 Months          +_ 5 ppm                  TPB,  TEB (E#D)
            50 ppm CO from each pick-up                             ~~                        SDSB (HD)
        3.  Random check two sites                2 Weeks           _+_ 5 ppm                  TPB,  TEB (E&D)
                                                                                             SDSB (HD)
      B.  Combustible Gas Alarms
        1.  Check calibration of meters with      Yearly           Meter set 25$ of LEL,      TPB - SHEDS  &
            a bag of 5250 ppm propane             (Change          (Alarm set 20#            fueling area
                                                  transducers       of LEL)
                                                  every 2 yrs)

-------
                                                                                                     -13-
                                 Test Equipment  Checks  -  Soak Area


 AREA                                       FREQUENCY           TOLERANCE                GROUP COVERED
Soak Area

A.  Check soak area temperature recorder    2 Months         +_ 1°F                        TPB

B.  Check Laboratory Barometers

  1.  Calibrate barometers                  monthly          j^.03 "HG                     TPB,  TEB(E
-------
                                                                                                           -14-
                                      Test Equipment Checks - Fuel System

	AREA	             FREQUENCY     	TOLERANCE	     GROUP  COVERED

VI.   Fuel System

      A.  Temperature Controls
        1.  Check fuel temperature                Daily at         45-52eF Test              TPB
                                                  startup          45-708F Prep

      B.  Visual Check, Indoor, and Outdoor
        1.  Check reteniton dike and pits         Weekly                 	                TPB
            for debris and water
        2.  Check for leaks at fittings           Weekly                 	                TPB
        3.  Manually cycle pneumatic valves       Weekly                 	                TPB

      C.  Heat Pump Air Filters
        1.  Visually inspect and change           2 Weeks                	                TPB
            if needed

-------
                                         Test  Equipment  Checks - CVS's
                                                                                                           -15-
      AREA
VII.  CVS

      A.  Tracer Gas Injection
      B.  Venturi Cleaning and Operational
             Checks
        1.  Visually inspect venturi
        2.  Check pressure and temperature
            transducers and Vmix computer
        3.  Check CVS dilution filters
          CVS Maintenance
        1.  Change sample filter elements
        2.  Clean probes, check fittings
            and lines
        3.  Check cyclonic separators
        4.  Visually check exhaust pipe
            gaskets and boots
        5.  Pressure check exhaust pipe
        6.  CPO Kits.  Verify active
            coefficients
FREQUENCY
 Weekly
 TOLERANCE
 Yearly
 Yearly

 Yearly
 Weekly
 Monthly

 Monthly
 Weekly

 Yearly
 Yearly
+2.Q% recovery.  Failure
require two additional
propanes within +1.8^.
Includes diesel heated
FID bag and continuous
integrated samples.
Clean if necessary
+2% of calculated

Less than 1" H20 drop
Probe vacuum less
than 12" Hg

Replace as necessary
  0.5*
GROUP COVERED
   TPB
  TPB,  TEB (E«D)
  TPB,  TEB (E*D)

  TPB,  TEB (E«D)
  SDSB  (HD)
  TPB
  TPB

  TPB
  TPB

  TPB
  TPB,  TEB (E«D)
  SDSB  (HD)

-------
                                         Test Equipment Checks  -  SHED's
                                                                                                           -16-
      AREA
FREQUENCY
 TOLERANCE
                          GROUP COVERED
VIII. SHEDS
      A.  Air Plow and Visual Inspection
        1.  Check mixing air flow rate
        2.  Visually inspect for leaks
        5.  Safety check the door and cable

      B.  Background Check
        1.  Check the background at the
            beginning and end of a 4-hour
            period, with the door closed.

      C.  4-hour Retention
          SHED Volumetric Check
          SHED SAC
 Yearly
 Yearly
 Yearly
 Yearly
 Monthly
 Monthly
 Weekly
600-1000 CFM
  0.4 grams/4hrs
•^4% Retention of
injected propane for
a 4-hour period.  Rerun
retention after repairs
are completed.

+2% Measured versus
calculated volume
(based on FID response).

Any reading outside
of the analysis sites,
three sigma.
                            TPB
                            TPB
                            TPB
                            TPB
                            TPB
                                                                                               TPB
                                                                                               TPB

-------
                                                                                                          -17-
      AREA
IX.   Dynamometers

      A.  Dynamometers Calibration
          Verification Procedure
          TP-302A
Test Equipment Checks

           FREQUENCY
      B.   Dyno Maintenance
        1.  Check mag plugs
        2.  Clean screens in water lines,
            fittings and lines
        3.  Lube bearings and couplings
        4.  Check bonding on rolls

      C.   H20 Softeners
        1.  Check with soap test
      D.   QC Timers
        1.   Check set points 4.50 and 5.50
            volts and the 5.00 volt drivers aid
            cal  signal

      E.   Dew Point Meters
        1.   As outlined  in Procedures
            TP 211 and TP 214 Procedures
       2.   Clean mirrors
            Weekly
            Monthly
            Monthly

            6  Months
            Monthly
            6  Months
            (Replace
            yearly)
           4 Months
           Weekly and
           Monthly
           30 days
Dynamometer

       TOLERANCE
      +1 second  -  actual
      versus  theoretical
      coastdown  times.  +0.2
      HP thumbwheel  versus
      indicated.   +0.1 second
      QC timer versus master
      timer.   Rerun  procedure
      for area affected after
      repair.
    Replace  if  needed
    Replace  if needed
     If  less  than a 50$
     reduction in hard
     water content, replace
     softner
    +0.01 volts
GROUP COVERED
  TPB
  TPB
  TPB

  TPB
  TPB
  TPB,  TEB (E«D)
  TPB
    Per  test procedure
  TPB

  TPB

-------
                                                                                                     -18-
                                Test Equipment Checks - Dynamometer

AREA	       FREQUENCY     	TOLERANCE	     GROUP COVERED

P.  Tire Gauges
  1.  Check on site tire gauge with         6 Months         +_ 2 psi                      TPB
      master gauge

G.  Raw Exhaust Analyzers
  1.  HC, CO, and C02 Span Check            2 Weeks          _+ 5% Full Scale            TPB
      with bottles

-------
EOD TEST PROCEDURE
TITLE
Critical Flow Orifice Calibration
ORIGINATOR
David Munday, Mechanical Engineer, Calibration and Maintenance
RESPONSIBLE ORGANIZATION
Calibration and Maintenance
TYPE OF TEST REPORT
Computer Generated
REPORT DISTRIBUTION
Calibration and Maintenance
Page 1 of 20
NUMBER
TP 210A
IMPLEMENTATION DATE
02-03-92
DATA FORM NO.
Form 2 10-01
COMPUTER PROGRAM
CFO Calibration Program
SUPERSEDES
TP210
REMARKS/COMMENTS

REVISIONS
REVISION
NUMBER

REVISION
DATE

EPCN
NUMBER

DESCRIPTION

IMPLEMENTATION APPROVAL
Test Procedure authorized on 02-03-92 by EPCN #102

-------
Revision:  0
Date: 02-03-92
                            Critical Flow Orifice Calibration
 TP210A
Page 2 of 20
                                   TABLE OF CONTENTS
                    1.   Purpose	3



                    2.   Test Article  Description	3



                    3.   References	3



                    4.   Required Equipment	3



                    5.   Precautions	5



                    6.   Visual Inspection	5



                    7.   Test Article  Preparation	5



                    8.   Test  Procedure	7



                    9.   Data Input	8



                    10.  Data Analysis	11



                    11.  Data Output	12



                    12.  Acceptance  Criteria	12



                    13.  Quality  Control  Provisions	13





                         Attachment A, CFO Calibration Schematic	15



                         Attachment B, Brooks Vol-U-Meter System	16



                         Attachment C, CFO Kit/Cart Information	17



                         Attachment D, CFO Calibration Data, Form 210-01.... 18



                         Attachment E, CFO Calibration Report	19



                         Attachment F, MTS CFO Implementation Report	20

-------
Revision:  0
Date: 02-03-92
                             Critical Flow Orifice Calibration
 TP210A
Page 3 of 20
   I.   Purpose

        The purpose of this procedure is to calibrate the Critical Flow Orifice (CFO) Kit for verifying
        Constant Volume Sampler (CVS) performance.


   2 .   Test Article Description

        Critical flow orifices are used for propane tracer gas injections.


   3.   References

        3.1     "Instruction Manual for the Critical Flow Orifice Kit Model 210;" Horiba Instruments
               Inc.; November 1978

        3.2     Letter from Horiba Instruments, Inc., to MSAPC QA Staff, August 1979

        3.3     "Brooks Vol-U-Meter Operating Instructions," Models 1052 through 1058; Brooks
               Instrument Division, Emerson Electric Company, 407 West Vine Street, Hatfield, PA
               19440; December 1977; Revision A

        3.4     Code of Federal Regulations. Vol. 40; Revised as of July 1, 1990; Parts 86 to 99,
               Section 86.119

        3.5     Memo; David L. Munday; November 5, 1991; Subject: "Equations for CFO Calibration'


   4.   Required Equipment

        The following is a list of the equipment used to perform a CFO calibration:

        4.1     Instrument grade propane

        4.2     Conoflow single stage regulator; 0-125 Ib spring, non-relief type

        4.3     Shutoff valve

-------
Revision: 0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 4 of 20
        4.4    The following components are contained in the CFO kit (see Attachment A, page 15):

               4.4.1    Precision pressure gauge; 0-100 psig, 8-inch diameter scale or larger, graduated
                       in 0.2-psig increments

               4.4.2    Thermometer, 0-120 °F, graduated in 0.5 °F increments

        4.5    The following components are contained in the Brooks Vol-U-Meter System (see
               Attachment B, page 16):

               4.5.1    Brooks Vol-U-Meter Control Box

               4.5.2    Valves; 3-way solenoid activated; two required

               4.5.3    Connection tubing and large, non-restricting vent and dump lines

               4.5.4    Back-pressure manometer; 0-4 inches of water, graduated in 0.5-inch
                       increments

               4.5.5    Brooks Vol-U-Meter, Model 1057; 3500-cc capacity (this is known as the
                       Brooks Prover)

        4.6    Seeka F5 optical sensors; two required

        Note:  One sensor is mounted at the 500-cc mark and the other is mounted at the 2000-cc mark
               (see Attachment B, Figure 2, page 16).

        4.7    DCI Timer with toggle switch

        4.8    Mensor Digital Pressure Gauge (central barometer), Model  11900; 0-32 inches of Hg,
               graduated in  0.001-inch increments.

        4.9    Vertex Floor Scale, Model 2158; equipped with Toledo Indicators, Model 8146

        Note:  The scale is located in the large soak area.

        4.10   CFO Kit/Can Information (see Attachment C, page 17)

        4.11   Form 210-01, "CFO Calibration Data" (see Attachment D, page 18)

        4.12   "CFO Calibration Report" (see Attachment E, page 19)

        4.13   "MTS CFO Implementation Report" (see Attachment F, page 20)

-------
Revision:  0
Date:  02-03-92
                               Critical Flow Orifice Calibration
 TP210A
Page 5 of 20
   5.   Precautions

        5.1    Cylinders containing compressed gases are used for this procedure. The technician must
               be familiar with the "EPA Laboratory Safety Manual" sections dealing with the safe
               handling, storage, and use of compressed gas cylinders.

        5.2    The gas cylinders and equipment must be checked for leakage, damage, and cleanliness.

        5.3    Use the Brooks Vol-U-Meter only with approved gases (see the operating manual for
               details).

        5.4    Although CFO kits have orifices for use with CO, pure CO should not be used because
               of its extremely toxic properties.  For safety reasons, EPA does not permit CO injections
               as a routine practice.

        5.5    The CFO kit must be in the gas lab prior to the start of the calibration for a minimum of
               20 minutes to ensure the kit is at room temperature.

        5.6    After each adjustment is made to the targeted pressure, the flow rate is allowed to stabilize
               for a minimum of two minutes.

        5.7    The precision pressure gauge is graduated in 0.2-psig increments but must be read to the
               nearest 0.1 psig.


   6.   Visual  Inspection

        6.1    Inspect all fittings with a leak detection fluid when the system is pressurized to 85 psig
               (see Section 7 for details).

        6.2    Verify that the CFO kit precision pressure gauge reading is zero when the shutoff valve is
               closed.

        6.3    Verify that the Brooks Vol-U-Meter back-pressure manometer reading is zero on the left
               side of the u-tube when the Control Box is in the "off" position. If it is not zero, release
               the set screws on the sliding metal scale and adjust it so the zero mark lines up with the
               bottom of the meniscus (on the left side).


   7.   Test Article  Preparation

        1.1    Disconnect the rosette from the cylinder pressure line.

-------
Revision:  0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 6 of 20
        7.2    Using the Vertex floor scale, weigh the CFO kit/can (CFO kit, propane cylinder, and
               cart).  Record the CFO total weight on Form 210-01.  The CFO Calibration Program
               calculates the net weight of the propane in the tank by subtracting the tare weight
               (displayed on each kit/can combination) from the total CFO kit/can weight. (See
               Attachment C, page 17 for details.)

               For a valid calibration, the net weight of the propane in the tank must be greater than 25
               Ibs. If it is not, replace the propane cylinder.

        7.3    Ensure that the DCI timer and the Brooks Vol-U-Meter Control Box are plugged into an
               electrical outlet.  If not, plug them in and allow the equipment to warm up for a minimum
               of two hours.

        7.4    Push the Brooks Vol-U-Meter Control Box button to the "off position.

        7.5    Connecl-the cylinder pressure line to the Brooks Vol-U-Meter Control  Box inlet pressure
               fitting.

        7.6    Adjust the regulator to 85 psig and allow the pressure  to stabilize for a minimum of two
               minutes*

        7.7    Push the Brooks Vol-U-Meter Control Box button to the "flow" position.

        7.8    Verify that there are no fluctuations in the piston movement and back-pressure manometer
               reading.  If fluctuations exist, notify the Calibration and Maintenance (C&M) Manager.

        7.9    When the piston reaches the top optical sensor, turn the cylinder valve counterclockwise
               to the "closed" position.  The system will now be pressurized.

        7.10   Inspect all fittings with a leak detection fluid.

        7.11   Push the Brooks Vol-U-Meter Control Box button to  the "off position.

        7.12   On Foira210-01, Section A, record all the required data. The previous calibration date
               and active coefficients are stored in the CFO folder. The CFO  folder is stored in the Gas
               Lab. The cylinder number, purity, and vendor are located on the tank.

-------
Revision:  0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 7 of 20
   8.   Test  Procedure

        A total of 24 data points are collected for a CFO calibration. Each data point consists of a
        measured supply pressure, within the 60 to 95 psig range, and an elapsed time reading. The
        target pressure starts at 60 psig and increases to 95 psig, in 5-psig increments, then decreases
        from 95 to 60 psig in 5-psig increments.

        To provide random confirmation data, the operator then sets 60, 75, 85, 70, 90, 95, 80, and 65
        psig.

        For each of the target pressures, perform the following steps:

     Sequence                          Description

        100      Turn the cylinder valve clockwise  to the "open" position.

        101      Push the Brooks Vol-U-Meter Control Box button to the "off  position.

        102      Adjust the regulator to set the supply pressure to within ±0.4 psi of the target pressure,
                 e.g., 60 psig must be 59.6 - 60.4 psig, 75 psig must be 74.6 - 75.4 psig, etc., for all
                 target data points.

        103      Allow the set pressure to stabilize for a minimum of two minutes. The stabilized
                 pressure must be within ±0.4 psig  of the target pressure.

        104      Read the precision pressure gauge to the nearest 0.1 psig.

        105      On Form 210-01, Section B, record the observed pressure under the column Actual
                 psig.

        106      When the Brooks Vol-U-Meter piston has descended to the bottom of the chamber,
                 push the DCI toggle switch to the right to stop the timer. Reset the rimer to zero by
                 pushing the toggle switch to the left.

        Note:   If this is the start of the calibration  process, the piston will already be at the bottom of
                 the chamber.

        107      Push the Brooks Vol-U-Meter Control Box button marked "flow."  This directs the
                 flow into the Brooks Vol-U-Meter, causing the piston to rise.

-------
Revision: 0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 8 of 20
     Sequence                          Description

        108     Verify that the Brooks Vol-U-Meter back-pressure manometer reading is 1.5 inches of
                water. If it is not, notify the C&M Manager.

        109     The DCI timer will start when the optical sensor is activated by the top edge of the
                piston reaching the  500 cc mark on the steel scale.

        110     Continue to flow the gas until the piston reaches the upper optical sensor (2000-cc
                mark). The DCI timer will automatically stop when the top edge of the piston reaches
                this point, thus indicating the elapsed time to flow 1500 cc.

        111     Push the Brooks Vol-U-Meter Control Box button marked "off."

                On Form  210-01, under the column marked At seconds (XX.XXX), record the
                elapsed time obtained from the timer readout.

        Note:   The At must be recorded before the Brooks Vol-U-Meter piston reaches the lower
                optical sensor (timer automatically resets). If the time has not been recorded prior to the
                piston reaching this point, repeat Steps 102 through 111.

        112     Repeat Steps 102 through  111 for each of the 24 calibration target pressures listed on
                Form 210-01 and record the required data. Each target pressure must be set in the
                order shown on Form 210-01.

        113     When all of the required data points have been collected, complete Form 210-01,
                Section C.

        Note:   See the Data Processing Flow Chart on page 9.


   9.   Data Input

        9.1    The technician opens  the CFO Calibration Program (on the C&M Macintosh computer)
              and enters the data recorded on Form 210-01.

        9.2    When all data has been entered, use the scroll bar and move the screen view to the right
              and preview the "CFO Calibration Report."

        9.3    The technician verifies that the "CFO Calibration Report" does not contain any acceptance
              criteria flags. If flags appear, see Section 12 for corrective action.

-------
Revision: 0
Date: 02-03-92
                              Critical Flow Orifice Calibration
                              TP210A
                              Page 9 of 20
                                 Data Processing Flow Chart
           Collect raw data using
             CFO Cal Data Form
          /Input the raw data
       /     T, P  and AT
            Data processing using
           CFO Calibration Program
                  (Excel)
             Examine output of
              CFO Cal  report
   Meets
 acceptance
criteria and
    QC
No
      Yes
                                             Computer operations
                                        updates coefficients & generates
                                        MTS CFO Implementation Report
                                       Examine MTS CFO Implementation
                                          & CFO Calibration Reports
                                                               Laboratory Automation
                                                                diagnoses errors in
                                                                coefficient data base
                                                             Yes
                                                       No
                                          CFO Cal. Data Form, Report
                                           MTS CFO Implementation
                                                documented

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Revision: 0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 10 of 20
        9.4    The technician saves the file by pressing the "Save Report" button. This will
               automatically save the data to the CFO Calibration folder on the hard drive and assign the
               file name as "CFO Cal Kit # NNNNN MM/DD/YY." The NNNNN will contain the kit
               number, and the MM/DD/YY will have the date that the data were entered into the
               computer.

        9.5    The technician then prints the "CFO Calibration Report" by clicking on the "Print
               Report" button.

        9.6    A technician, other than the one performing the CFO calibration, verifies that the data in
               the "CFO Calibration Report" and Form 210-01 are the same.

               If no corrections are needed, the technician signs and dates the "CFO Verification
               Report." The report is taken to the C&M Manager.

               If corrections are needed, they are identified on the report and it is returned for corrective
               action to the technician who performed the CFO calibration. The technician makes the
               corrections and repeats Steps 9.1 through 9.5.

        9.7    The C&M Manager then signs and dates the  "CFO Calibration Report," indicating that the
               coefficients can be updated on MTS.

        9.8    The technician inserts a blank 4-inch floppy diskette into the Macintosh drive. He/She
               opens the CFO Calibration folder and copies the file named 1011D-CFOCAL onto the
               floppy.

        9.9    At the computer input/output window, the technician completes a job request form.
               He/She then places the job request form, the  4-inch floppy diskette (with the electronic
               copy of the 1011D-CFOCAL file), and the signed paper copy of the "CFO Calibration
               Report" into an envelope.

               The envelope is then placed in the input basket. Computer operations will check that the
               C&M Manager has signed the report before implementing the MTS coefficients.
               Implementation of the new coefficients on MTS makes them available to the Tracer Gas
               Injection Program (1011S-TGI).

-------
Revision:  0
Date: 02-03-92
                             Critical Flow Orifice Calibration
 TP210A
Page 11 of 20
        9.10  Computer operations will generate an MTS CFO Implementation Report (see attached
              sample) containing the following information:

              Kit#

              Coefficients A, B, and C

              Entered By

              Implementation Date

        9.11  The envelope containing the 4-inch floppy diskette and paper copies of the "CFO
              Calibration Report" and  the "MTS CFO Implementation Report" are placed in the output
              basket where they can be picked up by the technician.

        9.12  The technician verifies that the data in the "CFO Calibration Report" and "MTS CFO
              Implementation Report" are the same. If no corrections are needed, the technician signs
              and dates the "CFO Calibration Report."

              If corrections are  needed, they are identified on the "MTS CFO Implementation Report"
              and it is taken to the Laboratory Automation Group for corrective action.

        9.13  When Steps 9.1 through 9.12 have been completed, the technician opens the CFO
              Calibration Program and pushes the "Update Data Base" button.  This  will update the
              CFO calibration data file named "1011D-CFOCAL" with the new coefficients.


   10.  Data  Analysis

        10.1  The "CFO Calibration Report" is examined for acceptance criteria flags, (f flags appear,
              see Section 12 for corrective action.

        10.2  The data in the "CFO Calibration Report" and Form 210-01 are compared independently
              by two technicians.

-------
Revision:  0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 12 of 20
        10.3   The "CFO Calibration Report" is reviewed and signed by the C&M Manager authorizing
               that the coefficients can be updated on MTS.

        10.4   The technician compares data in the "CFO Calibration Report" and "MTS CFO
               Implementation Report" to ensure that they are the same.

               If no corrections are needed, the technician signs and dates the CFO Calibration Report.


   //.  Data Output

        11.1   The "CFO Calibration Report," "MTS CFO Implementation Report," and Form 210-01
               are filed in the C&M CFO folder.

        11.2   The technician notifies the C&M midnight shift that the CFO kit has been calibrated and is
               ready for use.


   12.  Acceptance  Criteria

        The data must meet the following six criteria to be valid; a flag will  be displayed on the "CFO
        Calibration Report" if the data do not meet the criteria.

        12.1   The net weight of propane in the tank must be greater than 25 Ibs. prior to the start of the
               calibration. If not, Flag #1 appears on the spreadsheet and the calibration is void.
               Replace the propane cylinder, return to Section 7, complete a new Form 210-01, and
               repeat the calibration procedure.

        12.2   The difference between the start and end back-pressure readings must be 0.0 inches H.,0
               (a reading other than zero indicates friction in the Vol-U-Meter tube).  If it is not zero,
               Flag #2  appears on the spreadsheet and the calibration is void. Notify the C&M
               Manager, return to Section 7, complete a new Form 210-01, and repeat the calibration
               procedure.

        12.3   The difference between the start and end barometric pressure readings must be less than
               or equal to 0.12 inches Hg. If not, Flag #3 appears on the  spreadsheet and the
               calibration is void.  Return to Section 7, complete a new Form 210-01, and repeat the
               calibration procedure.  If after a second calibration attempt the data are not within this
               limit, notify the C&M Manager.

-------
Revision:  0
Date: 02-03-92
                               Critical Flow Orifice Calibration
 TP210A
Page 13 of 20
         12.4   The difference between the start and end CFO kit thermometer temperature readings must
               be less than or equal to 2.0 °F. If not, Flag #4 appears on the spreadsheet and the
               calibration is void. Allow the kit temperature to stabilize for a minimum of two hours,
               return to Section 7, complete a new Form 210-01, and repeat the calibration procedure.
               If after a second calibration attempt the data are not within this limit, notify the C&M
               Manager.

         12.5   The percent of point deviation from the best  fit curve must be within ±0.3% . If not,
               Flag #5 appears on the spreadsheet and the out-of-tolerance data points (actual psig and
               At seconds) may be rerun one more time. Cross out the bad data with a single line and
               initial the area. Open the CFO Calibration Program and make the necessary changes. If
               the flag persists, the calibration is void.

               12.5.1  Clean the CFO kit ruby orifice fitting in a sonic  bath.

               12.5.2  Return to Section 7, complete a new Form 210-01,  and complete the calibration
                       procedure.

               12.5.3  If after a second complete calibration attempt the data are not within the
                       specified tolerance, replace the ruby. Return to  Section 7, complete a new
                       Form 210-01, and complete the calibration procedure.

         12.6   The previous calibration date entered into the computer must  match the previous
               calibration date stored in the data base.  If not. Flag #6 appears on the spreadsheet
               indicating  that the coefficients are inactive. Look up the previous calibration date in  the
               CFO folder and verify that the correct date has been recorded on Form 210-01.  If the
               calibration date is recorded correctly, a computer problem may exist or a report may  be
               missing in the CFO folder; notify the C&M Manager.


   13.  Quality  Control Provisions

         13.1   The fittings are inspected with a leak  detection fluid.

         13.2   The CFO kit precision pressure gauge is verified to read zero when the shutoff valve is
               closed.

         13.3   The Brooks Vol-U-Meter back-pressure manometer is verified to be reading zero (for the
               left side of the u-tube) when the Control Box is in the "off position and the piston  is at
               rest on the bottom.

-------
Revision: 0
Date: 02-03-92
                              Critical Flow Orifice Calibration
 TP210A
Page 14 of 20
        13.4   If the DCI timer and the Brooks Vol-U-Meter Control Box are not plugged in, they are
               allowed to warm up for a minimum of two hours.

        13.5   The piston movement and back-pressure manometer reading are verified to ensure that
               there are no fluctuations.

        13.6   The flow rate is allowed to stabilize for a minimum of two minutes after each adjustment.

        13.7   The net weight of the propane in the tank must be greater than 25 Ibs.

        13.8   The CFO kit temperature is allowed to stabilize for 20 minutes prior to performing the
               calibration.

        13.9   When the piston is moving, the back-pressure manometer must read 1.5 inches of water.

        13.10  Actual pressure must be within ± 0.4 psig of the target pressure.

-------
o-
c
T: j
 R
                              CFO
                              Kit
                 LEGEND
C	Cylinder, propone
R	Regulator, non-relief type
V	Valve, shutoff
CFO	Critical Flow Orifice kit
P	Pressure gouge, precision
T	Thermometer, kit
QD	Quick Disconnect
CB	Control Box, Brooks Vol-U-Meter
5V 1,2	Solenoid Valve, three-troy
VM	Vol-U-Meter, Brooks
BPM	Bock-Pressure Manometer
TFM	Totalizing Flow Meter
           (Tube/Piston)
                                             CB                 VM
                                                 (See Figure 2)
                       Figure 1    CFG Calibration Schematic

-------
               OFF(VENT)
FROM CFO
t
         Brooks Vol-U-Meter
         Control Box
                                              V
                                                                     2OOO cc
                                         Brooks Vol-U-Meter
                          Back Pressure
                          Manometer
                                                                           Seeka F5
                                                                           Optical Sensor
                                                                           Optical Sensor
                                                                           Bracket
                                                                           Volume Scale (cc)
                                                          DCI Timer
                                                         I  xxx.xxx"!

                                                         RESET C3C> STOP
                                                                     500 cc
                                                                        Toggle
                                                                        Switch
                                                                 Seeka F5
                                                                 Optical sensor
                OFF(VENT)                      FLOW

                      Figure 2  Brooks Vol-U-Meter. Control Box and DCI Timer

-------
Date: 02-03-92	TP210A Attachment C                  Page 17 of 20
                                  CFO Kit/Can Information
        The propane weight is determined by subtracting the CFO kit/cart tare weight, displayed on each
        kit/can combination, from the CFO kit/cart total weight. The propane weight must be greater
        than 25 Ibs. for a valid calibration.
        The following items contribute to the CFO kit/cart total weight:
        1. CFO kit
        2. Propane cylinder with valve, regulator, and propane gas
        3. Portable can
        The following items contribute to the CFO kit/can tare weight:
        1. CFO kit
        2. Empty propane cylinder with valve and regulator
        3. Portable can
        Listed below are the tare weights of the CFO kits currently in use. Note that the CFO tare
        weights differ from kit to kit.
             Kit Number        Empty Propane       CFO Kit/Can        Tare Weight
                                Cylinder (Ib)             (Ib)                 (Ib) ~

            038625                   95                  183                278
            086942                   95                  180                275
            181102                   95                  150                245
            181103                   95                  150                245
            106380                   95                  182                277

-------
Date: 02-03-92
TP210A Attachment D
Page 18 of 20
Section A:
Technician's Name:
CFO Kit Number:
Current Date:
Date of Previous Calibration:
Calibration Stan Time:
Start CFO Kit Thermometer Temp
Section B: Collect 24 calibration
Target psig
(D 60
(2) 65
(3) 70
(4) 75
(5) 80
(6) 85
(7) 90
(8) 95
(9) 95
(10) 90
(11) 85
(12) 80 A
(13) 15(f~^
(14) 70\^— -.
(15) 65 v
(16) 60 ^.
(17) 60 \>
(18) 75
(19) 85
(20) 70
(21) 90
(22) 95
(23) 80
(24) 65
Section C:
Calibration End Time:
End CFO Kit Thermometer Temp:
Rubv Cleaned YES
Comments:
CFO Calibration Data
Cylinder #:





points in
Actual
(D
(2)
(3)
(4)
(5)
(6)
(7)
<*><
(9) X
r^
WOK
W3)
\V
\ ) 05)
^(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)

NO

Cylinder Vendor:
Cylinder Puritv:
CFO Total Weight:
Start Back Pressure:
°F Start Barometer:
the order listed below. /
*\
psig, (XX.X) At second
/? (1)
/ v
A\(2)
„ \\H
/r\\ V\ ,
^ ;/ $y
A \T ,1
\\\ \\ m
\\\\ \7
X \\\\ )/ (8)
v\\\\\ \V (9)
\\ \ N \ )/
\\ X \ ^ (10)
\\ -^ (11)

"V (13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
End Back Pressure:
°F End Barometer:
Ruby Replaced



Ib
inches H-,O
//-\ inches Hz
u
dsUM-XXX)
\T />
\\^/
\v
;/




















inches H-,0
inches Hz
YES NO

Form 21 0-01:02-03-92

-------

1
CH) Kit No: I0636O

CFOKit
Number
106360

IS'

,
1
2
3
4
5
6
7
0
10
11
12
13
14
15
16
17
IS
10
20
21
22
23
24
Actual
PSIG
60.0
650
700
750
aoo
aso
000
QSO
QSO
000
aso
800
7SO
700
650
600
600
7SO
aso
700
ODD
QSO
800
650




START
END
AV&. '
FLAGS
Technician
Name
Parker

Bock
Pressure
CH201
1.5
1.6
16
-
^^7
^FLA^//
•v
••
«5
<5
UUmJJIK: oc Limt Rags ire present
This CFQ Kit has problems. This is nsmple report.


^
/ 1
1
16
'2
3
14
20
4
13
IS
5
12
23
6
11
19
7
10
21
*
0
22



Delta
Vol
(DC)
1500

FLAS

Acliial
rtu;


CFQ Total
3QO

era
Fare Veiojrt
277
Propane
Weigh*
(Iba)
23
* 1

Delta t
(SEES)
/^0> 134061
^/76C/ 133.864
/ ,60 1 33626
^r^SS
Pro oe-

Date af
Previous Calibration
8/1/41

Coefficients
A= 256I13E-06
B= 7.442A7E-D3
C= -1336I8E-02

RUBY
CLEANED
REPLACED
VE&^JO
Nb

P,*-^1^
0530202
0531112
0532011
0571227
0560822
057 2644
Iff ^ 11 7.01 4\ 0607547
^-^ICr 1I&5SB\ 0600715
\r70 ^mM4^VO 606171
^TS/
ao
ao
ao
as
as
as
00
00
00
05
05
OS
DATA VERIFIED ftY:
COf FFICIEHTfi OK
TO IrPlEMEHT:
4O(i33l J 6650241
^1 01021 -/ SJ65 2000
103.084 0680646 \
102711 ^06Q21ST^
102003^-^ Ofid0256
QtA32^'
07.755^
07.7fl6\\
02.053 '^
02.775
8B.4HI
8B507
8B3fl7


^ 0.726660
0.727242
0.726037
^QCT^TO
0*33176
0*33230^
0*34321 \
^•J^'+B'P^+C
0530606
0530606
0530606
0571006
057 1006
0571006
0610871
0610071
0610871
0650200
0650200
0650200
0680364
0680364
0689364
0727703
JJ1727703
^^.7«5a77\
0*33515


OOCnFKIEMTfi VERIFIED ftV:



HSe±Oan-30-1«fl2 I3:J4 A

Date
ii/e/rQi

Near
Coefficients
B= 0.43046E-D3
C- -1.21324E-OI

Sfriff
-0088
0088
0258
0)048
-0218
0208
-0548
-0.108
-0448
-0018
0288
028
0)068
0.428
0.148
-0.158
-0088
-0.128
-0.148
OJQ58
-0038
-0028
-0048
0.108
FLAG£


«5
«S
fs
<*



DATEJ
DATE:
DATE:


Date: 02-03-92 TP 21 OA Attachment E Page 19 of 20

-------
Date: 02-03-92
TP210A Attachment F
Page 20 of 20
                           MTS CFO Implementation Report
          Implementation Date:

-------
EOD TEST PROCEDURE
TITLE
Gas Analyzer Calibration Curve Generation
ORIGINATOR
Linda Hormes
RESPONSIBLE ORGANIZATION
Laboratory Engineering Branch, Calibration and Maintenance Group
TYPE OF TEST REPORT
Analyzer Calibration Curve Analysis
REPORT DISTRIBUTION
C&M, Analyzer Sites, QC, and Data Validation
Page 1 of
12
NUMBER
TP204
IMPLEMENTATION
11-14-79
DATE
DATA FORM NO.
LB-205
DB-AA-601
COMPUTER PROGRAM
1251C-CALB
SUPERSEDES
N/A
      REMARKS/COMMENTS
           REVISIONS
REVISION
NUMBER
(1)
REVISION
DATE
12/15/88
EPCN
NUMBER
EPCN 70
DESCRIPTION
This EPCN authorized use of the Horiba NDIR CO/CO2 analyzers.
  IMPLEMENTATION APPROVAL
Test Procedure authorized on 11/14/19

-------
Revision: 0
Date: 11-14-79
                       Gas Analyzer Calibration Curve Generation
 TP204
Page 2 of 12
                                 TABLE OF CONTENTS
                    1.   Purpose	3
                    2.   Test Article Description	3
                    3.   References	3
                    4.   Required Equipment	3
                    5.   Precautions	4
                    6.   Visual Inspection	4
                    7.   Test Article Preparation	4
                    8.   Test Procedure	7
                    9.   Data Input	9
                    10.  DataHandling	,	11
                    11.  Data Review and Validation	11
                    12.  Acceptance  Criteria..	;... 11
                    13.  Quality Control Provisions	12
                    14.  Documentation	12

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'Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 3 of 12
   1.   Purpose

        The purpose of this procedure is to generate analyzer calibration curves for all ranges of all
        analyzers used by Light Duty, Heavy Duty, and Evaluation and Development  These curves are
        then used in the monthly analyzer calibration verifications (TP-303) which are done to assess
        analyzer curve stability.  A new curve must be generated whenever an existing curve is found to
        be out of tolerance, when a new analyzer is placed into service, when two or more secondary
        standard cylinders have been replaced, or when the top secondary standard cylinder is named or
        replaced. NOTE: Whenever a new curve is generated, a Span Point Change Notice must be
        completed.  Refer to Test Procedure 205, Span Point Change Notice.


   2.   Test Article Description

        All gas analyzers used for measuring vehicle exhaust and evaporative emissions


   3.   References

        3.1     Federal Register. Vol. 42, No. 124; June 28,1977; Sections 86.121-78 to 86.124-78

        3.2     EPA memo, Subject: Light Duty Testing Operations Tolerances; T. Hudyma; April 14,
               1977

        3.3     EPA Laboratory Safety Manual


   4.   Required  Equipment

        4.1     Calibrated digital voltmeter (DVM) with .01 volt resolution or better

        4.2     Secondary standard calibration cylinders for the appropriate gas and range being
               analyzed. See Step 7.13 for the method of selecting the correct cylinders. All secondary
               cylinders must have undergone Test Procedure 403, Gas Correlation, before they may be
               used as calibration gases.

        4.3     Portable calibration line of Teflon covered with braided stainless steel for introducing the
               calibration gases into the analysis system

        4.4     Form AA-601, Exhaust Gas Analyzer Data Form

-------
Revision:  1
Date:  12-15-88
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 4 of 12
        4.5    Form LB-205, Span Point Change Notice


   5.   Precautions

        5.1    The technician performing the calibration must be familiar with the Laboratory Safety
               Manual, especially Chapters 2 through 6, which deal with the safe handling of
               compressed gases.

        5.2    Cylinder carts must not obstruct doorways at the analysis sites. Doorways must remain
               closed to insure effectiveness of the fire extinguishing system.

        5.3    The technician must insure that there is no leakage of toxic gases and that the analyzer is
               properly vented to the exhaust ventilation system.

        5.4    Any time a new curve is generated or updated, a span point change notice must  be filed
               and the new span point posted at that analysis site as soon as the point is known. No
               official testing may be done until the new span point is posted.


   6.   Visual  Inspection

        Inspect the portable calibration line for cracks, bends, worn spots, etc.


   7.   Test Article Preparation

        1.1    Verify that the analyzer is operating according to the specifications given in the instruction
               manual and/or in-house analyzer specification sheet.

(1)      7.2    Verify that the analyzer is set in the proper operating configuration:

               NOx analyzer (TECO 10A):      OZONE - "ON"
                                            POWER - "ON"
                                            NO-NOx - "NOx"

               Methane analyzer  "CONTINUOUS CYCLE"
                               (Bendix 8295)       timer switch - "AUTO"
                                                  valve switch - "AUTO"

-------
Revision:  0
Date:  11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 5 of 12
               Values for pressure, temperature, and flow rates which must be observed are posted at
               the individual sites and on the curve printout Refer to the instruction manual and/or the
               in-house analyzer specification sheet for more detailed instructions, or consult with the
               Team Leader.

        7.3    Check that the strip chart recorder has sufficient paper and is inking properly.

        7.4    Check the calibration label on the calibrated DVM to insure that the due date has not been
               exceeded. If it has, the DVM must be recalibrated before the curve generation can
               proceed.

        7.5    Allow the strip chart recorder sufficient warm-up time (minimum of 20 minutes).

        7.6    Check the electrical zero of the strip chart by shorting the input terminals and adjusting to
               zero ±. 1 % of full scale.

        7.7    Attach the calibrated DVM to the analyzer output jack.

        7.8    Using the on-line working gases, zero and span the instrument on the appropriate
               multiplier range to verify that the strip chart recorder reading and analysis bench DVM
               reading equal the calibrated DVM reading ± .2% of full scale. If this tolerance is
               exceeded, make the necessary adjustments to the recorder or bench DVM and repeat the
               zero and span check.

        7.9    While performing Step 7.8, verify that the analyzer output noise level is less than ± .5%
               of full scale. Noise is defined as short-term cyclical variation of a signal from some
               average value.

        7.10   While performing Step 7.7, verify that the analyzer output drift does not exceed ± .2% of
               full scale per two minutes. Drift is defined as long-term directional change of value.

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 6 of 12
        7.11   Record the following data on the strip chart:

               Analyzer vendor
               Date
               Test site number
               Operator's name and ID number
               Gas analyzed and dilutent gas (e.g., CO/N2)
               Full scale (100%) voltage
               Sample flow rate
               Monitor set point on magnehelic
               Zero gain setting
               Span gain setting
               Air pressure (hip and GC analyzers)
               Fuel pressure (FID and GC analyzers)
               Sample pressure (FID and GC analyzers)
               Fuel type (FID and GC analyzers)
               Standard laboratory range
               Full scale concentration value of range being analyzed
               Analyzer property ID number

        7.12   At analysis sites where a calibration port IS provided, turn off the span gas flow to the
               untested analyzers by closing the valves of the appropriate gases located in the master gas
               control box at the site.  This prevents waste of span gases. Switch the analyzer being
               used to the  OFF mode and select SPAN for the on-site analyzers not being tested. This
               prevents waste of calibration gases.

               At analysis sites where a calibration port is NOT provided, switch the analyzer to the
               SPAN mode.

        7.13   Select the proper secondary standards to be used as data points in the curve. The curve
               should include these cylinders whose concentrations will produce the following
               approximate deflection reading at the range being calibrated:

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 7 of 12
               Nonlinear Analyzers                   Approximate Chart Deflections
               (NDIR - minimum of 8 data points)                   95
                                                                80
                                                                70
                                                                60
                                                                50
                                                                40
                                                                25
                                                                15

               Linear Analyzers                      Approximate Chart Deflections
               (FID, HFID, Chemil,                               90
               GC minimum of 6 data points)                       75
                                                                60
                                                                45
                                                                30
                                                                15

               If enough cylinders are not available to meet these requirements, consult the Team Leader
               for further action.  More cylinders may be used in the curve to provide Quality Control
               data on gas concentration uniformity.

               All secondary standards must have black sticker labels giving the EPA-named
               concentration.


     .   Test Procedure

     Test Sequence                     Test  Description

        101     Using the portable calibration line, connect the top secondary cyUnder to be used in the
                curve to the appropriate instrument gas input port.

        102     Adjust the instrument gas flow rate and pressure as closely as possible to the rates
                posted at the analysis site.  Continue to monitor them throughout the procedure.

        103     Zero the instrument using the on-line zero gas adjust the zero potentiometer until a
                stable and accurate zero is obtained.

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 8 of 12
     Test Sequence                     Test Description

                A stable reading is defined as one minute of measurement in which the drift variation is
                not more than ± .2% of full scale from the set point and the noise variation is not more
                than + .5% from that same set point The numerical value of the reading is the
                operator's estimate of the average reading occurring during the measurement period.
                The calibrated DVM is used for all measurements.

        104     Span the instrument by connecting the highest concentration secondary cylinder to the
                analyzer and adjusting the span potentiometer until the DVM reading reflects the percent
                of the actual concentration compared with the full scale of the range being analyzed.
                For example, if the range is 0-250 ppm and the top bottle is 230 ppm, adjust the DVM
                reading to 92% of full scale (230 ppm = 92% of 250 ppm). Or the span reading from
                the previous curve may be used again if the top bottle has not been renamed or
                replaced.

        105     Zero the instrument and allow the reading to stabilize. If the original zero does not
                return within + .3% of full scale, adjust the potentiometer until it does and repeat Step
                104.  Indicate the measurement area on the strip chart.

        106     Span the instrument using the highest concentration secondary cylinder and allow the
                reading to stabilize without adjusting the potentiometer.  If the DVM reading does not
                match the original span reading obtained in Step 104, repeat Steps 105-106. For each
                reading taken, write the cylinder number, the FJA-named concentration, and the
                observed DVM reading on the strip chart near the measurement area. Circle the DVM
                reading.

        107     Run the curve.

                Introduce the sequence of secondary calibration cylinders to be used as data points in
                the curve, in descending order of concentration. Obtain a stable DVM reading for each
                without adjusting the potentiometer.

        108     Zero the instrument

                After the lowest concentration standard has been recorded, reintroduce the zero gas and
                obtain a stable reading. If the reading has drifted more than ± .3% of full scale from
                the reading obtained in Step 105, repeat Steps 101-108.  If the tolerance limit is still
                exceeded, the drift problem must be corrected before the curve can be completed.

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 9 of 12
     Test Sequence                    Test  Description

        109     Respan the instrument

                Reintroduce the highest concentration standard for a reference span point. If the
                reading has drifted more than ± .3% of full scale from the reading obtained in Step 106,
                repeat Steps 101-108. If the tolerance limit is still exceeded, the drift problem must be
                corrected before the curve can be completed.

        110     Introduce the working span gas and obtain a stable reading without adjusting the
                potentiometer. Record the reading on the strip chart where it occurs along with the
                actual concentration and cylinder number. (This step provides information for TP-
                205.)

        111     Zero the instrument

                If the zero point has drifted more than ± .3% of full scale, repeat Steps 103-110.  If the
                zero point is still out of tolerance, the drift problem must be corrected before the curve
                can be completed.

        112     After testing is completed, turn the site span gases back on if they have been shut off.


   9.   Data Input

        9.1    The operator writes the cylinder number, the EPA-named concentration (found on the
              sticker tape attached to the cylinder), and the observed DVM reading on the strip chart
              near the measurement area. Zero and span points are indicated as such. The on-line
              working gas is identified as "WG." All DVM readings are circled.

        9.2   The operator completes Form AA-601 for each range analyzed.

              9.2.1    Lines 1-3, Instrument Identification, are completed using the codes on the back
                       of the form.

              9.2.2    Line 4, Limits, is completed.  The deflection limits define the upper and lower
                       limits of valid deflection readings on the DVM. The range change limits define
                       the upper and lower deflection readings on the DVM that signal the need for a
                       range change to computers on real-time systems.

-------
Revision: 0
Date:  11-14-79
                         Gas Analyzer Calibration Curve Generation
                                                                TP204
                                                                Page 10 of 12
        9.3
         On Line 5, Operator's Comments, the range being analyzed is given in % or
         ppm. The reason for the curve generation is given (e.g., analyzer maintenance,
         new top cylinder, old curve out of tolerance, etc.). Any special operating
         instructions or comments about the test must appear here.
         Columns 1-11 of Line 7 are completed using the codes on the back of the form
         as follows:
          Cols. 1-2      "zero-span type" - always "01" (no software zero and span)
          Cols. 4-5      "curve form" - "01," which forces the curve through zero
          Col. 8        "degree of fit" - depends on the linearity of the analyzer,
                        usually "2" for NOx, methane and "3" for CO, CO2, and HC
          Col. 11        "weight factor" - always "2," which minimizes percent of
                        point  deviations
          Col. 23        "X" in "to be filed"
9.2.5    Lines 10-29 are concerned with the cylinders involved in the analysis.
          Cols. 1-12     the cylinder numbers are listed
          Col. 14        applicable only if a gas blender was used
          Col. 16        "X" if the cylinder is "to be named" (working gases)
          Cols. 20-32   not applicable
          Cols. 34-44   the known or nominal concentration is listed for each cylinder
          Col. 46        "X" if the cylinder is to be used as a calibration data point
                        (secondary standard cylinders)
         All such cylinders must have a known concentration value.
          Cols. 48-55   the DVM readings written on the strip chart are entered
The operator completes Form LB-205 for each range analyzed. Refer to TP-205.

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 11 of 12
   10.  Data Handling

        10.1   The completed Form AA-601 is submitted for processing.

        10.2   The printout, Analyzer Calibration Curve Analysis, is obtained after processing.


   11.  Data Review and Validation

        11.1   The technician examines the Analyzer Calibration Curve Analysis for each analyzer range
               and determines the validity of the curves.

               11.1.1   All figures in the column under "curve fit deviation" marked"% point" must be
                       within ± 1% for the curve to be valid. The "average deviation" found at the
                       bottom of this section may not be more than + .5%.

               11.1.2   Percent deviations should be random with respect to +/- signs. If like signs are
                       clustered in the center and/or at the ends of the curve, the degree of fit may have
                       to be increased by one order. Consult with the Team Leader in such cases.

               11.1.3   If inflection points are flagged in the printout, these must be investigated by
                       Quality Control before the curve is accepted.

               11.1.4   The percent of nonlinearity should not be more than 10% for all analyzers
                       except NDIRs. If the nonlinearity of an NDIR exceeds 15%, it is investigated
                       by the Team Leader before the curve is accepted.

                       If the curve is valid, the procedure is complete and a Span Point Change Notice
                       must be generated. Refer to TP-205.

                       If the curve is not valid, refer to the attachment, Troubleshooting Flowchart for
                       Invalid Analyzer Curves, for corrective measures.


   12.  Acceptance Criteria

        12.1   All zero and span rechecks must fall within ± .3% of full scale of the original readings.

               The curve must be valid according to the criteria set in Section 11.1.

-------
Revision: 0
Date: 11-14-79
                         Gas Analyzer Calibration Curve Generation
 TP204
Page 12 of 12
   13.  Quality  Control  Provisions

        13.1   All analytical instruments must be properly warmed up and in a test-ready mode prior to
               use.

        13.2   All DVMs used in the procedure must have undergone a routine calibration within the
               past 90 days.

        13.3   At least eight data points should be used in curves for nonlinear analyzers. At least six
               data points should be used in curves for linear analyzers.  If these numbers cannot be
               met, the Team Leader is consulted before the curve is run.


   14.  Documentation

        14.1   Copies of the Analyzer Calibration Curve Analysis are signed and dated by the
               Calibration and Maintenance Supervisor and distributed as follows:

               One copy is retained by Computer Operations for update purposes.

               One copy is stored in the Calibration and Maintenance active curve file, replacing the old
               curve if applicable.  The old curve is stored in the inactive file.

               One copy is kept in a file at the analyzer site. The old curve is destroyed.

               One copy is sent to Quality Control through Computer Operations.

        14.2   The Span Point Change Notice is submitted to Data Validation for verification and
               distribution.

        14.3   The strip chart is filed in Calibration and Maintenance under the analyzer site number and
               date of completion.

               A copy of Form AA-601 is filed under the analyzer site number and date of completion
               in Calibration and Maintenance.

-------
TP204 -  Gas" Analyzer  Calibration  Curve Generation
Strip Chart-Documentation-
          r ANAL ID No., tf..% *2:. REC TYPE.
          ,: MINOR.££	MAJOR. .«*.... VPS./#..._
            ZTTO...^..-- Sf^ANTTT.-.•..•-.-•;-. TUNE.
            FID PRESSURE
            AIR	FUEL	SfAPL-
            WaTYPE....	CURVE REQ-.
                                                    !"-

-------
                            EXHAUST GAS ANALYZER CALIBRATION DATA FORM
                                                                         USE 0 FOR ZERO
                                                                           aroR tETTE
IXJTnUMENT
 t.NTIFICATlON
COMMENTS
                                                                   Tpn  I IJ I I I  IJ  I I I  IJ  I I I  I j I  I I IJ I I  lol'j

                                                                         ' '..I ' ' I  '.J  I M  IJ  I I I  IJ I  I I IJ I I  H.|

             17I71or.(pffl  H l"[J1oin»lorM
             tV      to     10      10*
nrwTfftrrrfrf T.j HUI"B iTT'nnrfh iT7T!j uTa 111 11111111111 j 11 i°n
 *&      tv     io' .     ti      4V      ailoo'     i»      oo Ioil     ,01  ••^•* 'sji •	(7*
                                           L«
                                           ,T*
                                           n
                                       L.OWC H LIMIT
                                                                            FULL-4CALC
                                                                            ieo%| VOLTAOI
                                                                                        mTTTTTTTITI I | I  I I  I I II I8!'
                                                                                            _^     _j     _,      -^     _
            OPERATOR'S COMMENT- THIS COMMENT WILL ONLY BE PRINTED ON THG CALIBRATION REPORT.
    T| I I  I IJ I  I I I.J I I  I I.J I I  I IJ I  I I IJ I I'l IJ  I I I  IJ  I I I  IJ I  I I IJ I I  I IJ I I I  IJ  I 11  IJ  I I I  IJ I HTfTT
            HIE COMMENT '
  11111 i  111111 1111111111 i  M n 1111  MI  1111111 M 11111  ji 111111 1111 M  11  n 11 M n i  IT
      P     io1      if     ti<  ~  il"     til     iJ      4|'      il|      •«     I*      if      •••      10'     »•'
pi7iioifpa3a|:iii •ijTi'lj rfbj'iTiTjTT'i g^yj,",^-^-"-^^^"-
 CYLINDER NUMflER         *  *u > -1
                                                                                                                     R
SPAN BlENO CYL.
Oil. RLtNOCYL.

UP TO TO
CYLINDERS AND
 i ENDS
                                                                             n IB 11111   rri M i
                                                                               Otf      H      •*     «•'
              Hill] MI
             |..<.i| II» -OAT* f ROM THE PREVIOUS CALIBRATION WILL K U8ED If BLANK.
                                                                      NOTE: RIGHT JUTTIFY ALt NUMCHIC FIILM: LEFT JUSTIFV All ALPHANUMERIC FIELDS.

-------
1NSTRUHCNTS t
SUBSTANCE
HYDROCARBON
CARBON
MONOIIOE
CARBON
OIOIIOE
DUDES or
NITROGEN
01TGEN
SMOKE
SULFATE
UO_JU
INST
HCAN
COAN
C02A
NOIA
0104
SMN
SLFA
iStsLsi
CALIBRATION
trpr
CONCENTRATION
02 COBRECTION
CONCENTRATION
CONCENTRATION
CONCENTRATION
CONCENTRATION
ORAcirr
CONCENTRATION

SIGNAL
Jiii-
MCAN-C
fHCAN-02
COAN-C
C02A-C
NOIA-C
OIGA-C
SMKN-OP
SLFA-C
        -
CABO 1  (CULS  '-».
c«fln T  ICOLS  ]T-3
                                                                                  58-19. 4B-49. S«-S«I
                                                                CODE  EQUIVALENCE

                                                                 01    PASCALS - NT/SO "fTES
                                                                 0?    BABrES - O'NCS/SO CM
                                                                 0]    PARS
                                                                 04    MILLIBARS
                                                                 OS    CM KG 10 OtC Cl - TORR
                                                                 0«    «M MG 10 OCG Cl
                                                                 97    CM "20 It, OCG C)
                                                                 08    MM M20 14 OtG C)
                                                                 0*    CM OIL (l.'S SGI
                                                                 10    MM OIL 11.75 SGI
                                                                 10    ATMOSPMEBES
                                                                 It    IN HO 02 DIC n
                                                                 22    IN N20 14 OCG Cl
                                                                 21    IN OIL (1.75 SGI
                                                                 2*    PSIA
                                                                 25    PS10
COM  EQUIVALENCE

 28   e-l.000.000 PPM
 2T   0-  500.000
 2A   0—  250tOOO
-B-!
21 1
22
tl-
2«
1»
1*
IT
l»
IS
|4
11
12
11
.«
~Q9
0«
OT
0»
05

01
02
01
- 100(000
SOiOOO
1- 25.000
10(000
s.ooo
2(500
ItOOO
500
250
100
so
25
10
5
2.5
1.0
.5
.25
.10
.05
.025
.010
.005
.0023
)' .0010
                          -100 PCT
                          - 50
                          - IS.  0-25

                          - 10
                          -  5
                          -  2.5
                          -  1.0
                              .5
TFRB HO SPUN KITM SIOUL
        »NO PRESSURE CORRECTION
                                                                CUBVg fBPM
                                                                C1QQ T fCQLS 4-«il

                                                                CODE  EOUI«*LENCt

                                                                 • 1   POLTNOMUL VITH * nRO INTERCEPT
                                                                 02   POLVNOHI1L "ITH > NONZERO INTERCEPT
                                                                 01   CURVEtLL TYPE FIT.  HISTORIC OMLT--NOT
                                                                        SUPPORTED
                                                                nreBrr nr m
                                                                C.BB T I COL HI
                                                                CODE  EQUIVALENCE
                                                                 1-*
                                                                      fit * POLYNOMIAL OF DEGREE t-».
                                                                        (USE I FOR LINEAR ANALTZER5
                                                                        AND » »R NOIR>
CODE  EOUIVlLENCC

ttOt  B«0 >N«LTSIS
HR10)  H>G >N1LTSIS - MICH  INSTRUMENT
L8»0  S«0 MtLTSIS - LOW INSTRUMENT

MOO»  MOOiL *N>LVSt5
HMOO  MO04L ANALYSIS - HIGH  1NSTBUMCNT
LHOR  MWAL ANALYSIS - LOU INSTRUMENT

MAST  MASTER ANALYSIS
MMST  MASTER ANALYSIS - HIGH INSTRUMENT
LMST  MASTER ANALYSIS - LOK  INSTRUMENT
61S_lIEIS
CAM 9  iCOl
UTTCMTTHia fACTBg
gAfln t  fpoi  in

CODE  EQUIVALENCE

  I   MIGHT THE SQUARE Or THE DEVI
        or THE CURVE FROM THE DATA
        WITH A >EIGMTINC FACTOR OF
  2   VEIGHT THE SQUARE OT THE OEVI
        or THE CURVE rROM THE DATA
        VtTM A WEIGHTING FACTOR OF I/T
        .
Ifi-BE-tlLCO.
CABP T trot ?^l
ENTER * LETTER •«" ir TMf CALIBRATION
SHOULD BE riLED AS A PENDING CALIBRATION.
OTHERVISE NO RESULTS. MILL 6E SAVED.
                                                                      FMFNT TYPF
                                                                      in*p? icm < tfa.  I*,  im
CODE  EQUIVALENCE

 Oil  CAB10N EQUIVALENT
 «I2  METHANE
 01*  PROPANE

 021  CABDON MONO! IDE
 022  CARDON OIOIIOE

 Oil  NOI
 012  NO

 0*1  SULFUR
 0*2  S02
 0*1  504
 04*  H2S
 0»S  H2SO*

 051  SMOKE

 Oil  OIYGEM
 062  020NC

 OT1  AIR

 0(1  NITROGEN

 0*1  HELIUM
ENTE* » LETTER "«" IN Bat or TMOCE COLU-NS
TO INDICATE HHE1MER GAS IS FROM A RLCNO. A
KNOW) CYLINDER. OR A CYLINDER TO BE NA»CO.

         COLUMN
CODt  ABBREVIATION  OAS
          BLEND

          KHOMN
           CYL.

           CYL.
          TO BE
          NAMED
                                                                                    BLEND FRON T«0 CYLINDERS

                                                                                    KNOKM CYLINDER CONCENIRAt10^


                                                                                    UWNOdtt CYLINDER TO BE ~»-<0
CM IBBflTtOI DATA POINT
CiffQ^ IQ'if? if PL 4&I
ENTCT A LETTER "«• FOR EVERY MfASUBEMfNY
THAT REPRESENTS A RHUM DATA POINT FOW CO«»uMNG
A CALIBRATION CURVE OR NAMING CYLINDERS.

-------
•••• PRJCFSSfDJ  10103130  06-OS-74
                                               ••• AhALY/r.H CALIHKAT10N CURVE  ANALYSIS •••
                                               •••                                      •••
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CALIBRATION OATF   J  6- *-79
TEST SITE NUMBER   I   A?If,
GAS ANALYZE I       ICO
niLl'FNT G\S        INtTROQF.N
cnurfnt-Mri'iN UK'IT:   w
         i AH  RAt>C«F. I    ?n
         ID ^0    i  I V2S
                              ANALYZER VENDOP
                              INSTKUMFNT NAMF
                              EPA UECAL ID  NO
                              STr.NAL LEAn
                              MABfinlAHr
                              CAI M (iA
                              Hi FNOt.K OECAL
                                             TD
CO/IN-C
  MB AC,
SAMPLE FLOW PATE
"ONITOH StT POINT
/tRO GAIN SETTING
SPAN GAIN SFTTING
IUNF KFAIUNG
f la A IH PRF.SSIMF.
FID fULL PRtSSUHF
FID SAMP PRESSURE
4.0
0.0
0.0
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SCFH      VALID  DFFL.   IJPPFR LIMIT
          VALIL  DKH-.   LUWLR LIMIT
          RAtlG(.  CHAIlGt IJPPLR LIMIT
          RANbt  C-(A'IOt LO.LR LIMIT
          FULL-StsLL (IOC1.) OEf L .
          FULL-bCALfc (HIO>1 VULrAOF:
          FULL-SC41L (lOOi) CONC.   I
                                                                                                                              110.000
                                                                                                                              .10.000
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n.n
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0.1
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CONCFNT^ATIONS
Cvi. INnEK
(Ml FN>VD) CALClM.nTFIi
n.o
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440.6 44V.rt
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ANALYZFP SIGNAL ICALIRHATIUNI cuxvf FIT DEVIATIONS
Mt/VbUKEO COKKECTEU
X X


94.600 94.ISOU
HU.900 HO. 900
71.100 71.100
SS.400 5S.40U
44.200 44.200
3n.f>00 30.hOO
H CYLIMDtM
HO. 900 94.nOO 90.6011
1 LINCAR FIT
1 CALC. CONC.
1 (LC)
1 2tr<.J.O
1 CUHVK FIT 1
i CALC. CONC. i
1 (CfJI |
1 2239.9 |
CUNCt NTRATIO'4
PAIIOS
NC/CC LC/CC
0.'<'»9S2 1 .00 1 3/

-------

*»*»»n*oott it 01
• *»
••• A^ALV/r.H
• •*

• ••••••••**•'
F'lO f.'l 13 AI T|M» : 4: 0 «'.»L»ZFH VFN'inR :>«SA
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TfsT siu •J-II-HF> : A?I(, ff« I'ECAL in NO I09s4t
r,AS *•:»!. r>F • :CO SIGNAL Lf AO COAN-C
FUlL-'-CAL- Cf.'lC : 2540.? M»"-J,AWt PANOF
CO'lCf -iT^MI'lf UMt: PPM H<-tOt HHHI.
ST«-intt-'i ' AH PAII-.F: ?n OPERATOR in NO 13935
fjuATio'.s A-'O corFFirifMTs
X = < 1
r M
f «l IH't tlOli oliAfcfl) a II. i)

>«»«>i»»*g»»i«t«* ••••••••»•«•• AAAAA
••• AA A
CALIHHATION CURVE ANALYSIS ••• AAAAAA
••• AAAAAA

ZE'JO SPAN TYPE I 1
ClIKVE FORM 1 1
DEC.KEE FIT 1 3
MEIGHIING FACTOR 1 2
132
(A5»K » A4»X • A3»X » A^"X • Al )
C C C C
Al 0.0
H2 0.1>y*9?70E»U«!
A3 0.44t>430!4E-Ol
',4 0.14*S09/E-OJ
a5 0.0
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                                222
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                           AA  ItliZtt
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66
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:»Ll?t'4U1" I'-L'LF _ PE^CrM FHLL-iC/VLF CH1WT OrFI ECT I IN 1'b PH'-I LO/NITPOGEN _' .
0 . (; . 0 1
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473.71 33.
4VS.SI 34.
517.4) 31.
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SBJ.9| 3P.

-------
TROUBLESHOOTING FLOWCHART  FOR INVALID ANALYZER CURVES
                          ! SEE TEAM
                          I LEADER TO
                          j LOCATE PRO-
                          , BLEM

-------
                       SPAN  POINT CHANGE  NOTICE
                                     NEW SPffl BOTTLE''
tu
Oi
Qi
r .
w



cc.
( "~t
— 1
o






n-
LU
o
o
3
UJ




QI v xv\u X
ANALYZER SITfc NUMBER /
GAS TYPE \ /
RANGE NUMBER X\
/ ^v
CURRENT SPAN CYLINDER NUMBER
EPA TAG/CONCENTRATION
/
POSTED SPAN SET POINT

NEW SPAN CYLINDER NUMBER
'
EPA TAG CONCENTRATION ; Y3
CHECK RESPONSE / XO
UPPER CHART D^FL. BRACKET 12
LOWER CHART DEFL\ BRACKET U
v^
UPPER CONCENTRATION BRACKET Y2
LOWER CONCENTRATION BRACKET n
Y2 - Yl / \ AY
CALCULATED BOTTLE CONC. \ YO
YO = Yl + (AY/AX) (XO - XI)
% DIFFERENCE = YO - Y3 v inna,
(MUST BE <±1«)
NEW SPAN SET POINT X3
X3 = XI + (AX/AY) (Y3N^ Yl)
x


'\


-

j




\




'

^



^
«
•\



-




\
^-^
•


!
'















/

,.


;


















1
j
i

!
    CALCULATED BY:
    VALIDATED BY:
                                                     \
DATE/TIME EFFECTIVE:   /'	

NOTE:  If nd data i,s available for the old span bottle, \he new bottle-most be
      checked-tfsfng secondaries.  See-form LB205B.     \
     X2 = the next higher chart deflection  to XO on the curve cal-ibration table
     XI = the next lower chart deflection to XO on the curve calibration table
     Y2 = the next higher cone, corresponding to X2 on the curve calibration  table
     Yl = the next lower cone, corresponding to XI on the curve calibration table
                                                                             LB205A

-------
EOD TEST PROCEDURE
TITLE
Dynamometer Calibration Verification
ORIGINATOR
Don Paulsell
RESPONSIBLE ORGANIZATION
Calibration and Maintenance, Light Duty Diagnostics
TYPE OF TEST REPORT
Computer Report, Data Base Analysis
REPORT DISTRIBUTION
File hard copy in diagnostics; data and results are in computer file.
Page 1 of 12
NUMBER
TP 302A
IMPLEMENTATION DATE
8/16/82
DATA FORM NO.
Form EOD 302-01
COMPUTER PROGRAM
LCS E.DCHECK, DYPLOT
SUPERSEDES
TP302
REMARKS/COMMENTS
The three test procedures which deal with calibration and verification of Clayton chassis dynaometers are:
TP 202, Dynamometer Calibration - Fricu'onal Horsepower
TP 207 A, Dynamometer Calibration - RLPC Electronics
TP 302A, Dynamometer Calibration Verification
REVISIONS
REVISION
NUMBER

REVISION
DATE

EPCN
NUMBER

DESCRIPTION

IMPLEMENTATION APPROVAL
Test Procedure authorized on 08/16/82

-------
Revision: 0
Date: 8-1642
                         Dynamometer Calibration Verification
 TP302A
Page 2 of 12
                                 TABLE OF CONTENTS
                   1.   Purpose	3
                   2.   Test Article  Description	3
                   3.   References	3
                   4.   Required Equipment	3
                   5.   Precautions	4
                   6.   Visual Inspection	4
                   7.   Test Article  Preparation	5
                   8.   Test  Procedure	5
                   9.   Data Input	9
                   10.   Data Handling	9
                   11.   Data Review  and Validation	10
                   12.   Acceptance  Criteria	10
                   13.   Quality Control  Provisions	11
                   14.   Documentation	12

-------
Revision: 0
Date: 8-1642
                            Dynamometer Calibration Verification
 TP302A
Page 3 of 12
   1.   Purpose

        This procedure is used to verify several aspects about the calibration of a Clayton ECE-50
        dynamometer in fulfillment of the requirements of 40 CFR 86. The verification involves making
        simple checks on the control and display functions and performing several coastdowns at
        different inertia weight and horsepower settings. It is assumed that the electronics have been
        calibrated as specified in the Clayton manual and TP 207A and that the dynamometer has been
        calibrated using TP 202.


   2 .   Test Article Description

        2.1    A direct drive, variable inertia (1000-6875 in 125-pound increments) chassis
              dynamometer (Clayton ECE-50) with automatic road load power control capability and
              digital display of horsepower and speed

        2.2    The original Clayton circuit has been rewired so that the indicated horsepower is based
              solely on front roll speed and torque, but the front/rear roll speed indication is still
              selectable.

        2.3    Some dynamometers have been modified to display a 5-volt reference signal for driver
              trace recorders and speed displays.


   3.   References

        3.1    Federal Register. Vol. 42, No. 124; Tuesday,  June 28,  1977; 86.116-82  (d)(3), 86.118-
              78 (b)

        3.2    Clayton Instruction Manual R-8713

        3.3    "Proceedings of the Quality Control Symposium on Dynamometers" - June 27,1977,
              held at EPA

        3.4    Engineering Operations Division files on dynamometers


   4.   Required Equipment

        4.1    Dyno calibrator vehicle - 4000 point, V-8, fitted with lifting jacks and recording
              equipment

-------
Revision:  0
Date: 8-16-82
                            Dynamometer Calibration Verification
 TP302A
Page 4 of 12
        4.2    Master coastdown timer and cabling, plus the 60-tooth gear speed sensor assembly

        4.3    Extension cords, as required

        4.4    Data Sheet (Form EOD 302-01)


   5.   Precautions

        5.1    Inflate the drive tires to 45 psig to protect against damage from heat and distortion.

        5.2    Align the vehicle on the dynamometer rolls and attach the cable winch loosely enough to
               allow the vehicle to rise to its full lift height

        5.3    Operate the cooling fan within 12 inches of the vehicle radiator.

        5.4    Vent the vehicle exhaust to the building exhaust system.

        5.5    The coastdowns should be run right after warm-up of the dynamometer to insure that the
               bearing friction remains stable.

        5.6    The cable between the master coastdown timer and the dynamometer electronics box must
               be securely connected to insure good electrical contact.

        5.7    Verify the action of the vehicle lift while the car is stopped. It should raise quickly but
               lower slowly.

        5.8    Always verify that the cable, chocks, and electrical lines to the vehicle are disconnected
               before the vehicle is removed from the dyno.


   6.   Visual  Inspection

        6.1    Verify that the speed and torque meters read 00.0 when the car is off the dynamometer
               and the roll brake is not applied.  Have C&M check and adjust the voltages or meters if
               the readings exceed ±. 1.

        6.2    Other visual inspections are performed as part of the test procedure.

-------
Revision: 0
Dale: 8-16-82
                            Dynamometer Calibration Verification
 TP302A
Page 5 of 12
   7.   Test Article Preparation

        7.1   Place the coastdown vehicle on the dyno and set the MECO brake switch on to enable the
              lift; connect the 60-tooth gear, torque and speed signals, and the 115 VAC power plug.

        7.2   Chock the front wheels and attach the winch cable loosely.

        7.3   Verify the proper operation of the vehicle lift jacks, coastdown timer, and totalizing
              counters.

        7.4   Verify that the vehicle factor pot is set to a value of zero.

        7.5   Verify that the master timer is triggered by the Clayton tach signal and that the speed
              counter totalizes the "digital" tach signal from the 60-tooth gear.


   8.   Test Procedure

        Eight inertia weights are verified twice a month. Four weights and horsepowers are done each
        week as shown in Table A and on the data sheet The rear roll friction is verified weekly as part
        of the warm-up process.

     Sequence                         Description

        101     Obtain a blank data sheet (Form EOD 302A-01) for the dyno being tested.

        102     Enter all data and obtain the calibration thumbwheel values needed for the coastdowns.
                These are on the dyno calibration tables and/or on a lookup table in the calibrator
                vehicle.

        103     Review the recent data for the dynamometer to highlight aspects which may require
                close observation or need to be noted in the comments.

        201     Engage the 6875-pound inertia and set the thumbwheel to the value shown in the
                current version of Table A.

-------
Revision:  0
Date: 8-16-82
                           Dynamometer Calibration Verification
 TP302A
Page 6 of 12
     Sequence                         Description

        202     Place the speed selector to FRONT.

        203     Lower the dyno lift brake and slowly turn the rollers to verify all flywheels are
                engaged.

        204     Accelerate to a steady 50 mph and maintain this speed to warm up the PAU and
                flywheel bearings. Perform Steps 205-210 during this warm-up period.

        205     Dial the four thumbwheel values shown on line 2 of the data sheet and record the
                indicated horsepower at FR=50 mph.

        206     Set TW= 10 and set the timer module to MANUAL/STOP. Reset all counters to zero.
                Resume and maintain the speed a FR=50±. 1 mph.

        207     Switch the Count/Stop switch to COUNT for about 10 seconds. On the data sheet,
                record the torque, speed, and time counts, as well as the IHp meter reading. Reset the
                timer module to AUTO/STOP.  Verify that the set points are dialed to 45 and 55.

        208     Verify the operation of the coastdown timer module four times during the last 5 minutes
                of warm-up by performing a dyno coastdown (vehicle lift activated). The 6875-pound
                inertia is used; the thumbwheel setting is selected to give AHp equal to 13.5. The
                thumbwheel can be selected from the dyno calibration or the current version of Table A.

        209     Record the coastdown time for each run on line 3 of the data sheet. This time should be
                approximately 31 seconds.

        210     If the difference in times (MAX-MEN) is less than .3 seconds, the dynamometer is
                stable and the inertia coastdowns may begin. If not, perform additional coastdowns to
                see if four consistent values can be obtained. If the tolerance cannot be achieved,
                continue testing but report the condition to C&M and VA&T.

        211     Change the coastdown timer trigger input from the Front Roll to the Rear Roll tach
                banana jack on the dyno.

        212     Accelerate to 60+ 2 mph, hold that speed for about five seconds, and activate the
                vehicle lift, allowing the dyno to coast down by itself to 30 mph.

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Revision: 0
Date: 8-16-82
                           Dynamometer Calibration Verification
 TP302A
Page 7 of 12
     Sequence                         Description

        213     Record the RR coastdown time on line 3 of the data sheet and the value of RRFHp Cal
                from the current version of Table A.

        214     Listen for abnormal noise during this coastdown and verify that the coastdown timer
                trigger points are functioning within + . 1 mph of 55 and 45.

        215     Lower the vehicle and stop the dyno.

        216     Raise the dyno lift and engage the 4000-pound inertia.  Set the thumbwheel to a value
                of 10.0.  Change the coastdown input to the Front Roll tach banana jack and set the
                master timer selector to AUTO/STOP.

        217     Trace the template ramp-up and ramp-down profiles (0-60 @ 2.5 mph/sec separated by
                a 1-minute cruise at 60 mph) on a driving trace. Thread the driver's aid to prepare for
                the transient PAU performance test

        218     Set the low trigger point at 5 mph. Leave the high trigger at 55 mph.

        219     Lower the dyno lift. Accelerate to 50 mph FR to verify the horsepower and inertia
                operation.  Stop the vehicle.  Reset the counters.

        220     Turn on the driver's aid chart feed. When the ramp trace is reached, accelerate the
                vehicle at the constant rate to 60 mph, staying within + 2 mph at any point in time.

        221     Switch the Auto/Manual switch to MANUAL to hold the counts until they can be
                recorded on line 4 of the data sheet

        222     Maintain about 60 mph, switch to AUTO,  and reset the counters.

        223     When the ramp-down trace is reached, decelerate at the constant rate to a complete stop.
                Record the counter readings.

        224     Shut off the driver's aid.  Reset the low trigger point to 45 mph.

        225     Remove the driver's trace so it can be stapled  to the data sheet later.

-------
Revision: 0
Date: 8-16-82
                            Dynamometer Calibration Verification
 TP302A
Page 8 of 12
     Sequence                          Description

        300    INERTIA CQASTDOWN TESTS

        301     For each inertia coastdown shown in Table A, perform the following steps:

        302     Stop the vehicle and raise the roll brake.

        303     Select the inertia weight and set the thumbwheel horsepower determined from the
                current version of Table A. Inertia weights are to be run in the sequence specified in
                Table A for the respective weeks.

        304     Lower the roll brake and verify the inertia flywheel engagement.

        305     Accelerate to 50 mph as indicated on the speed meter and note the indicated horsepower
                at a steady 50 mph.

        306     Record the indicated horsepower on the data sheet

        307     Accelerate to 60 mph and maintain speed until the readings stabilize. Set to
                AUTO/STOP and reset all the counters to zero.

        308     Activate the vehicle lifting device, maintaining dyno speed until the tires clear the
                rollers; then release the accelerator pedal.

        309     Allow the inertia assembly to decelerate through the 55-45 speed interval.  Note the
                indicated horsepower as the inertia speed passes 50 mph.

        310     Record this indicated horsepower on the data sheet.

        311     Record the times from the master and quick check timers on the data sheet If the
                master timer does not work, record the quick check timer data in the master time
                column and indicate the switch in the comments on Line 1.

        312     Repeat Steps 302 - 312 for each inertia included on the schedule specified in Table A.

        313     Lower the vehicle, stop the dyno, and raise the lift brake.

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Revision: 0
Date: 8-16-82
                            Dynamometer Calibration Verification
 TP302A
Page 9 of 12
     Sequence                          Description

        314     Perform the visual check of the 1-second tolerance (master-theoretical) and submit the
                data for computer processing as specified in Section 10. Validate the results as
                specified in Section 12. Repeat any points that exceed the tolerances.

        315     If all results are acceptable, disconnect all electrical wires and restraints from the
                vehicle.

        316     Verify that the lift pads are fully retracted, turn off the MECO brake switch, and remove
                the vehicle from the dyno site.


   9.   Data Input

        9.1    Verify that all entries on the data sheet are complete and within the ranges of
              reasonableness. Data not collected can be blank or zeros.

        9.2    Submit the data sheet to Operations for processing by the LCS program E.DCHECK.


   10.  Data Handling

        10.1  The attached flow chart illustrates how the data are processed and stored.

        10.2  Data sheet entries should be keypunched and batch processed on LCS.

        10.3  The report will be printed and the data stored. The report consists of three pages - the
              data echo, the verification report, and a quality control summary. These are shown in the
              attachments. Read/Write errors on the data file are also indicated by a record dump in the
              QC summary.

        10.4  The results also are written to an LCS file for statistical and graphical analyses, obtainable
              by typing BREAK, then "$RUN DYPLOT" on a production "Prod" DecWriter.

-------
Revision: 0
Date: 8-16-82
                           Dynamometer Calibration Verification
 TP302A
Page 10 of 12
   11.  Data  Review and Validation

        11.1  All entries and calculations are checked by Data Control for reasonable results. If entry
              errors are detected, the data is corrected and reprocessed.

        11.2  Data Control verifies that the acceptance criteria of Section 12 are met

        11.3  Any data or results on the printout that do not meet the criteria are either flagged on page
              2 under Quality Control Comments or circled in black ink by Data Control. This printout
              is used for the copy distribution.


   12.  Acceptance  Criteria

        The following criteria are checked by the technician responsible at the time the procedure is
        performed. These criteria represent Federal Register compliance. If either of them cannot be
        met, the dynamometer is immediately removed from service, and may not be used until C&M has
        resolved the problem and verified the acceptability of the dynamometer

        12.1  Verification Data Coastdown Time Difference (Master/Theoretical):  (Step 311) This
              value must not exceed + 1.0 second. Any value outside these limits should be
              reconfirmed by the technician performing the verification.

        12.2  Verification Data IHp (3) Steady 50 mph:  (Step 306) All values must be less than or
              equal to ± 0.2 Hp of the thumbwheel setting.

              The following criteria are checked by Data Control after the data are processed and are
              either flagged under Quality Control Comments or circled if they are exceeded. Copies of
              the data report are distributed to the C&M and VA&T Supervisors for evaluation. The
              C&M Supervisor is responsible for resolution of the indicated problem(s) as soon as time
              permits. The dynamometer remains in use until the investigation is complete.  At that
              time, the C&M Supervisor will document the justification for deviation or remove the
              dynamometer from service.

        12.3  Warm-up Thumbwheel Check:  (Step 205)  The differences between IHp @ 50 readings
              and the thumbwheel settings should not exceed + 0.3. The average difference should not
              exceed ± 0.2.

-------
Revision:  0
Date: 8-16-82
                           Dynamometer Calibration Verification
 TP302A
Page 11 of 12
        12.4  PAU Hysteresis Check: (Steps 220-223) The hysteresis between ramp-up and ramp-
              down data should not exceed 1 mph, 1 ft-lb, or 0.4 Hp.

        12.5  Warm-up Coastdown: (Step 209)  The difference (MAX-MIN) in coastdown times
              should not exceed 0.3 seconds.

        12.6  50 mph Speed Check. 6Q-Tooth Gear  (Step 207) The front roll speed calibration should
              agree within + 0.2 mph of the 60-tooth absolute measurement. If die speed calibration is
              acceptable, the torque and Hp differences from theoretical should be ± 1 ft-lb and + 0.4
              Hp, or approximately ± 4%.

        12.7  Rear Roll FHp Check: (Step 213) This value should not be less than 0.150 FHp and not
              greater than 0.350 FHp.

        12.8  Verification Data IHp & 50 mph During Coastdown: (Step 310)  These values should
              not exceed ± 0.2 Hp of the indicated horsepower at a steady 50 mph and should not
              exceed + 0.3 Hp of the thumbwheel setting.

        12.9  Master/Quick Check  At Difference: The quick check timer on the site should agree with
              the master timer within ± 0.1 second.


   13.  Quality  Control Provisions

        13.1  The acceptance criteria in Section 12 are monitored by the Quality Control Group for
              trends and offsets. If a significant offset is noticed, QC immediately brings it to the
              attention of C&M, who must take corrective action to restore the central tendency of the
              data to near the zero line. If the four-month average of the verification coastdowns
              exceeds ± 0.5 seconds, C&M will investigate the trend.

        13.2  The general behavior of each dynamometer is presented at the monthly diagnostic meeting
              and priorities for corrective action are set at that time. Any outstanding deviations (Steps
              12.3-12.9) are also discussed.

        13.3  Corrective actions must be reviewed and approved by the C&M Supervisor before the
              dyno site is released for testing. Verbal notification of approval should be made to the
              VA&T Supervisor. A written description of the corrective action should be sent to
              VA&T and QC for documentation purposes.

-------
Revision:  0
Date: 8-16-82
                           Dynamometer Calibration Verification
 TP302A
Page 12 of 12
        13.4   After any repair that does not require a full calibration (TP 202 or TP 207A), this
              procedure or the applicable pans should be repeated before the dyno is accepted for
              testing.
   14.  Documentation

        14.1   The monthly summaries are copied and distributed to VA&T, C&M, and Quality Control.
              The data sheet, printout, and ramp trace are filed in a dyno file folder as specified.

        14.2   Corrective actions must be documented in sufficient detail to provide a "before" and
              "after" comparison of dynamometer performance. Quality Control must receive a copy
              for audit purposes.

-------
                          DYNAMOMETER   CALIBRATION   VERIFICATION   DATA  SHEET
       GENERAL

       INFORMATION
       SOmph FR

       
-------
TABLE A - DYNAMOMETER VERIFICATION TEST DATA (AS  OF 07/01/82) AND FLYWHEEL  ENGAGEMENT CHART
                                                                         TP-302A
DYNO
SITE
CAL DATE
MM-DD-YY
AVG.
RRFHP

THUMBWHEEL HP SETTINGS FOR PREP AND VERIFICATION COASTDOWNS
        FLYWHEEL
        ENGAGEMENT
        CHART
                             IW =
                            AHP =
                            t.At
D001
D002
D003
D004
D005
D006
D007
D207
D208
D209
08-14-81
02-23-81
05-19-82
10-30-80
03-27-8O
09-26-81
01-30-80
03-23-81
06-25-80
08-09-79
.308
.262
.169
.239
.235
.257
.301
.195
.272
.341
2K2
2*1
IK
TRIM
500
250
125
16875
13.5
30.927
10.6
10.2
10. 8
10.4
10.2
9.9
9.5
10.5
9.7
9.8
PREP
X
X
X
X
X
X
X
5000
15.2
19.977
12.9
12.7
13.1
12.8
12.9
12.4
12.2
12.7
12.2
12.2
4000
12.2
19.911
10.2
9.9
10.1
10.0.
10.1
9.5
9.4
9.9
9.4
9.4
3500
10.6
20.052
8.8
8.4
8.6
8.8
8.5
8.1
7.9
8.7
8.0
8.1
3000
9.2
19.803
7.5
7.1
7.5
7.5
7.4
7.1
6.8
7.5
7.1
6.8
FIRST & THIRD WEEKS
X
X

X




X
X
X




X

X
X



X

X



2500
7.6
19.977
5.9
5.5
5.6
5.8
5.6
5.2
5.2
5.7
5.3
5.2
2250
6.9
19.803
5.2
5.0
4.8
5.2
5.0
4.5
4.5
5.1
4.7
4.5
2125
6.5
19.850
4.8
4.6
4.6
4.9
4.7
4.2
4.1
4.7
4.5
4.0
2000
6.0
20.243
4.4
4.2
4.2
4.5
4.3
3.8
3.8
4.4
4.1
3.8
SECOND & FOURTH WEEKS


X
X
X




X
X

X



X
X


X


X
X




-------
                  Dynamometer Verification Data Processing
  Perform
  TP-302A
Fill in the
data sheet.
Submit to
Operations.
                                     I
                                  Operations
                                  inputs  via
                                  batch on  LCS
 Report
Run  E.DCHECK
on LCS
I
   Dynamometer Verification Summary
                                 Store
                                 Results
                                 on
                                 D.DCHECK
"Break" then
 $RUN DYPLOT
 on LCS PROD
 Decwriter
Enter the
dates for the
plot period
requested.
Reports/plots
 Process
 data

-------
07/02/83
09:3;:3C
R.UCHECK
    SYS1KMS KEAl.-l]
                                                 PHI   ••    ••   ••   IM   ••   ••
                                                 IMt:  MONfflTTPb.l^*^ Y *^ff!)D  ^^m  PjJf^  5^^
                                          ******************************************
                                          **  DYNAMOMETER C AL IliK»T ION VERIFICATION «*
                                          **             INPUT DATA ECHO           **
                                          **      SITE:  0007    DATE:  b-3o-82     •»
                                          t*****************************************

GENERAL
INFORMATION


SUE
***«
D007 •
DATE
MO DY YR
*»-**-**
6-30-62*
TIME
Hh MN
* * : **
5:30"
bAHO-
MtTER
***,**
2B.9H *

ID
**** *
17211
                                                                       COMMENTS
                                                                       *************************************************
                                                                       UbEO UC TIMER •
       50KiPH FH
          TW=10.0
           .**.*
           10.0 .
                                     WAKM-UP  ANU  CHECK
                                          TW VS  1HP
        Tw=5.0
         **.*
          5.0 •
Tw=15.0
 »*.»
 15.0.
                                                      **.*
                                                      10.0
      **.*
       0.0
                     SPEEU CHECK TKslO.O
                      60 TOIUH GEAR
         GEAR        TOKljUfc
         COONTS      COUNTS     OtL T
         ******.     ******.    **.***
           1«90J.«      9517.C     9.613.
                                IHP
                                • *.«
                                10.0'
       MHM-OP
       COASTOOWNS
          TW
          *V.«
                              ****.
                              6tt75..
              f)EL Tl
              **.***
              31/713,
      DEL T2
      **.***
      31.706 .
UEI. 13
•*.«**
31.712.
OEL T<*
**.***
31.616.
DEL T(KR)
***.***
 31.153*
FHP CAL
* . * **
0.301«
       SPEED TORUOE
       PAU
       HYSTERESIS
                      **.*
                      10.0'
                                          RAMP-OP  hi  a. 5 MPH/SEC
              GEAR
      IW      COONTS
      ****.   ******.
      "4000..
                                  ( 5-55 I-.PH  )
                                     TllHUIIE
                                     COUNTS      lit I.  T
                                     **»***.     **.***
                                       10003;     20.415.
                                                                 HAMp-OOWN 3 2.5 MPH/SEC
                          (  55-5
                GEAR        TUHuUt
                COUNTS      COUNTS
                ******.     ******
                                                       DEL T
                                                       **.**•
                                                       20.025
       VERIFICATION
       DATA

[.«
« *** .
5000.'
flOOO.'>
3500.'
3000..

AHP
**.*
15. 2«
I. .2"
10. 6»
S.2.

TW
* * . *
12. 2«
9.<4«
B.O.
6.6«
HP a>
50 SS
** . *
12.3 •
9.1 '
tt.O •
6.9 -
HP a
50 UC
** .» .
12.3.
9.5.
8.1-
7.0 .
MAS (EH
DEL T
**,***
19,«'40*
19.930*
19.fl<40«
19.790.
OCHECK
DEL T
**.***
19.«<4U*
19.930*
19.B«0 *
19.790 t

-------
07/02/B2
            09:31:30
                        R.DCHECK
                                       SYS
                                         ******************************************
                                         «* DYNAMUMETEW CALIBRATION VERIFICATION  «»
                                         **          VERIFICATION REPORT          **
                                         **     SITE: ooo/    DATE:  6-3o-»2      *•
                                         ******************************************
GENERAL INPUT DATA
******************
DATE:  6-30-62   BAROMETER: 26.96 INHG

OPERATOR in: 17261  DYNO SITE: D007
COMMENIS: USED UC llMER

PROCESSED: 07/02/H2  09:29:20

ALL DATA AND RESOLTS HAVE BEEN VERIFIED
FOR CORRECTNESS AND ACCEPTABILITY
       VERIFIED B» ti^JilijU.1
       FILE ONE COPY IN THE DIAGNOSTICS
       DOCUMENTATION FILE AND DISTRIBUTE THE OTHERS
                                                     WARM-DP AND CHECK
                                                     *****************
                                                           IHPii  DIFF     HUFF
                                                     Tw    "SOSb  l»iP-rw   IHP-TW
10.0
5.0
15.0
10.0
1 (I . 0
5.0
ib.o
10.0
0.00
0.00
0.00
0.00
0.000
0.000
0.000
0.000
                                                     AVE
                                                            0.00
                                               0.00
                                                                              2.5 MPH/SEC iwa 4000 TW=  10.0
                                                                              PAII HYbTEKESIS CHECK
                                                                              *****************************

                                                                                         SPEED   TOKUUh   IHP
RAMP-UH
RAMP-DOWN
DIFF
AVE
TMtOK
OIFF (A-T)
X01FF
31.b24
32.060
0.556
31.602
30.000
1.802
6.007
13. 244
13.362
0.130
13.313
12.000
1.313
10.S43
3.069
3.177
0.067
3.133
2.6t><4
0.469
17.609
WARM-UP
TW=  9.5
*********
DEL Tl =
DEL T2 =
DEL 13 =
DEL T4 =
MAX-MlN =
MEAN =
ST DEV =
XCV =
                Iw= 6B75
                ********
                 31.713
                 31.7B6
                 31.742
                 31.816
                  0.1030
                 31.764
                  0.0442
                  O.U91
REAR ROLL  IW=155
*****************
DEL T =    31.152
FHP CHK =   0.302
PHP CAL =
OEL FHP =
XUEL FHP =
                                          50-MPH SPEED CHECK
                                          TW=10.0, faO-TUOTH GEAR
                                          ***************************
                                                 SPt EO
TORUDE  IHP
0.301
0.001
0.366



AVE
THEUH
UIFK
XOIFF

50.602
bO.UOO
CoTTo^
iTToTr

26.7hO
27.6^5
(-0.270
-0.999

10.0
10.2
-0.2
-2.2
                UUALITY-COIMTROL  COMMENTS
                (»S KEFEK  TO  TP-302A CwITEHIA)
                ****************************************
                5)50MPH CHK,  i'DIFF CSHU>.2;TO«0>1; IhH>.4)
       DYNAMOMETER VEHIF1CAIION DATA
       *****************************
       1W
             AHP
                  HP i)  HP «'  MASTER  UCHECK  DUF
                  50SS  50UC  OEL T   OEL 1   OtL T
                                                                     OIFK     X01FF
                                                             THEOR   MASTER-  MASTER-
                                                             UEL T   IhfcuR    THtOH
       5000  IS.2  12.2  12.3  12.3  19.B40  I
       4000  12.2   9.4   9.4   9.5  19.930  14.930
       3500  10.6   0.0   B.U   tt.l  19.H40  19.B40
       3000   9.2   b.6   6.9   7.0  19.790  19.790
o.ooo
0.000
0.000
o.ooo
If. 977 .
19.911
20.052
19.803
-0.137
0.019
-0.212
-0.013
-0.666
0.093
-1.059
-0.1)67
                                           AVERAGES   0.000
                                                               -0.066    -0.430

-------
0*7/02/82
09:31:30
            H.UCHECK
                                  SYSTKt-.!)
                                            PNOD
                                                        PAGE
                                         A*****************************************
                                         ** UYNAI«<)ntTEK  CAl.I'IKAT ION  VERIFICATION **
                                         **  flJIJK MONTH  lUJALlfY  CUN1KOL  SUMMARY  **
                                         **      siu:: 0007    DATE:   b-30-82    **
                                         ******************************************
AVERAGE OIFF
DATE
MM-OO-YK
3- 3-62
3-10-82
3-17-82
3-24-82
3-30-82
a- 8-62
4-22-82
4-26-82
5- 4-62
5-12-82
5-19-82
5-26-62
6- 3-82
6-11-82
6-16-62
6-23-82
6-30-82
RH
FHP
0.296
0.267
0.315
0.309
0.305
0.320
0.307
0.298
0.2h«.
0.316
0.000
0.304
0.420
0.305
0.290
0.321
0.302
OIFF
IHP-TW
-0.020
-0.050
-0.050
0.000
0.000
0.000
o.oou
-0.050
-0.070
0.050
o.uoo
-0.050
-0.020
o.ooo
-0.050
0.050
0.000
XDIFF
IhP-1*
-0.30
-0.50
-0.50
0.00
0.00
0.00
0.00
-0.50
-0.60
0.50
0.00
-0.50
-0.30
0.00
-0.50
0.50
0.00
PAU
SPEED
-0.60
-0.40
0.47
0.21
-0.7»
-0.04
0.00
0.11
-0.11
0.54
0.00
-0.07
0.00
0.00
0.00
0.38
0.56
OIFFtOOwN-UH)
lOKUUfc
-0.163
-0.286
0.565
0.345
-O.i50
0.144
0.000
0.038
O.OH3
0.382
0.000
0.235
0.000
0.000
0.000
0.446
0.136
IMP
-0.11
-0.10
0.17
0.10
-0. 15
0.03
O.UO
0.02
0.01
0.14
0.00
0.05
0.00
0.00
o.oo
0.13
0.09
6H/5
KEAN
31.0H3
29.968
31.302
31 .026
30.95b
30.703
30.876
30.HU5
30.416
30.779
0.000
31.047
30.h38
30.773
31.214
30.985
31.7b4
b" FH
SPEfcU
-0.006
-0.019
0.036
0.042
0.116
0.1»b
0.104
0.060
0.049
0.060
0.000
0.034
0.020
0.000
0.000
0.060
0.602
UIFF CHECK
TUKUUE
-0.261
0.000
-0.314
-0.317
-0.214
-0.1/2
0.175
-0.277
-0.279
-0.267
0.000
-0.364
-0.365
0.000
-0.351
-0.181
-0.270
IMP
-0.100
0.000
-0.100
-0.100
-0.100
0.000
0.000
-0. 100
-0.100
-0.100
0.000
-0.100
-0.100
0.000
-0.100
-0.100
-0.200
TIMtK
M-OC
-0.059
-0.066
-0.066
-0.064
-0.056
-0.073
0.000
-0.075
-0.074
-0.067
-0.081
-0.100
-0.092
-0.103
0.088
0.076
0.000
OIFF
M-1HEUR
0.254
-0.105
0.619
0.023
0.177
-0.221
-0.207
-0.069
-0.206
0.072
-0.263
0.436
-0.263
0.048
0.021
0.260
-0.086
X01FF
M-ThEOR
1.273
-0.530
3.100
0.112
0.665
-1 .106
-1.038
-0.445
-1.041
0.362
-1.317
2.192
-1.320
0.241
0.105
1.301
-0.430
       AVERAGES
       ********

       N =
       MIN
       MAX

       AVERAGE

       STO OEV
        16      10      10
     0.267  -0.070   -0.80
     0.420   0.050    0.50

     0.310  -0.026   -0.29

     0.031   0.032    0.33
   12      12     \
-------
                                                                                                                                       25.105
in water, the water in the exhaust gas must not be allowed to condense.
The NO2 sample train must be heated to about 175°F.
  Exhaust gas samples (such as those collected in bags), which have been
allowed to stand for a few minutes or longer, will contain larger concentra-
tions of NOi than tail pipe exhaust samples which were analyzed immedi-
ately, because upon  standing the NO oxidizes to NO>.
    C2.1 Theory—The principle of operation of the ultraviolet analyzers
is based on the differential  absorption  of light energy at 4000 A  where
NO] has a strong absorption band. Light is supplied by a tungsten filament
lamp with  calibration  accomplished with  known  low concentrations of
NO2 in stainless steel cylinders. Extreme caution must be used in achieving
a clean sample system for calibration and exhaust analysis.
    C2.2  Interference—No response is obtained from an NO2 ultraviolet
analyzer with a 13.5 in cell for the following gases:
                        12%  CO2 + 5%  CO
                        567 ppm hexane
                        1000 ppm propane
    Water saturated Nj
  There is a slight interference from NO.  Approximately 1  ppm NOj is
indicated  for each 130 ppm of NO.
CONSTANT  VOLUME  SAMPLER  SYSTEM  FOR  EXHAUST
EMISSIONS  MEASUREMENT—SAE  J1094a
    SAE Recommended  Practice
Kr|Mirl til Anhuntilivr KlIllsMont (:*>inillllltT;i|)|IliAr(l Jtillr 1H7 I ,imlii>MI|ilrlrlv Irv isi-d l>\ Auloinnlivr Km

  Scope—This SAE  Recommended Practice describes  uniform laboratory
techniques  for employing (he constant  volume sampler  (CVS)  system  in
measuring various constituents in the exhaust gas of gasoline engines installed
on passenger cars and light trucks. The techniques described relate particu-
larly to CVS systems employing positive displacement pumps. In some areas
of CVS practice, alternate procedures  are given as a guide toward develop-
ment of uniform laboratory techniques.
  The report includes (he following sections:
     I. Introduction
     -'. Definitions
     3. Test Equipment
       3.1 Sampler
       3.'2 Bag Analysis
       3.3 Modal Analysis
       3.4 Instrument Operating Procedures
       3.5 Supplementary Discussions
       3.6 Tailpipe Connections
       3.7 Chassis Dynamometer
     4. Operating and Calibrating Procedure
       4.1 Calibration
       4.2 Operating Procedures
     5. Data Analysis
       5.1 Bag Analysis
       5.2 Modal Analysis
       5.3 Background
       5.4 Fuel Economy
     6. Safety
   /. Introduction:  Development  of CVS System—Constant volume sampler
(CVS) systems have been used since the late 1950s. The engine exhaust to be
sampled is diluted with ambient air so that the total combined flow  rate of
exhaust and dilution air  mix is nearly constant  lor all engine operating
conditions. The CVS system is sometimes called a variable dilution sampler.
Recently constant volume sampler systems have been abbreviated PDP-CVS
or CFV-CVS.  The PDP-CVS system is the older system that uses a positive
displacement pump to maintain a constant total flow. The CFV-CVS  system
uses a critical flow venturi to maintain a nearly constant total flow. Some of
the newer CFV systems no longer use  a heat exchanger to bring the  mix of
engine exhaust and dilution air to a constant temperature, but instead moni-
tor the mix temperature continuously in order to calculate  the total  flow
accurately.  These CFV systems  are not constant volume samplers, but since
they are used  to measure emissions, the units are discussed here.
   Hydrocarbons in the dilution air were  recognized from the first as a prob-
lem in the CVS procedure. Studies were initiated on the feasibility of  remov-
ing the unwanted hydrocarbons. As a result, the installation of charcoal filters
in the dilution air system was chosen as the most practical solution. Charcoal
does not remove any of the hydrocarbon materials, but it does stabilize their
concentration level during a given test and thereby permit the collection of an
accurate background sample.
   2. Definition!—The following definitions apply to the term indicated as the
term is used in this recommended practice.
     2.1 Analytical Train—A general  term to  define the entire system re-
quired to sample and analyze a particular constituent in exhaust gas. Typi-
cally, this train will include items such  as tubing, condenser, paniculate filter,
sample pump, analytical  instrument, and flow meter.
     2.2 Calibration Curve—Normally, the dependent vai iable^, the concen-
tration of the  calibration  gas, is plotted  as a function  of the  independent
variable x, the instrumental voltage. For nonlinear analyzers, a polynomial of
degree no greater than the fourth power is used. Sufficient data points  should
           :\|ilil I'l
                                                                                          H. Kill ....... 1 1 h.ilivi-
be used to adequately define the analyzer response. The calibration curve
should agree to within 1% of the measured data point.
    2.3 Calibration  Frequency — Analyzers  should be  checked  at  least
monthly to determine if significant change has occurred in the calibration. In
addition, the calibration should be verified when a problem  is suspected and
when large gain shifts are observed.
    2.4 Calibrating Gas — A gas mixture of accurately known concentration
which  is  used  periodically to calibrate the analytical instruments. Usually,
calibration requires a number of mixtures of different concentrations. Cali-
brating gases are usually divided into groups such as NBS standard reference
gases, golden standards, primary standards, and working gases. The naming of
the working gases should be traceable to the NBS standard reference gases.
    2.5 Chassis Dynamometer — A laboratory power absorption unit capable
of simulating to a limited degree the road operation of a vehicle. The dyna-
mometer should possess the capability to simulate the inertia and road load
power developed by a vehicle.
    2.6 Chemiluminescent (CL) Analyzer — An instrument which measures
nitric oxide by measuring the intensity of chemiluminescent radiation from
the reaction of nitric oxide with ozone. The addition of a converter will permit
the measurement of the  oxides of nitrogen.
    2.7 Chock — A block or wedge that prevents movement of the wheels of a
vehicle.
    2.8 Coastdown — The procedure used to determine the  total horsepower
absorbed by a  dynamometer at 50 mph (80 km/h). The time required for the
rolls to coast down from 55-45 mph (88-72 km/h) is observed.
    2.9 Constant Volume Sampler (CVS)— A  device for collecting samples
of diluted exhaust gas. The exhaust gas is diluted with air in a manner that
keeps the total flow rate  of exhaust gas and dilution air constant throughout
the test. The device permits measuring mass emissions on a  continuous basis
and also, through use of a second pump, allows a proportional mass sample to
be collected.
    2.10 Converter— A  thermal or catalytic: reaction device which usually
precedes the chemiluminescent analyzer  and converts oxides of nitrogen to
nitric oxide. The  converter may also convert ammonia and other nitrogen
containing compounds to nitric oxide.
    2.11 Counter — A mechanical and/or electrical  device that totalizes the
number of revolutions of the CVS for each test phase.
    2.12 Curve Fitting — See calibration curve, Lagrangian fit, polynomial fit.
    2.13 Detector — That component in  an analytical instrument which is
sensitive  to a particular  gas.
    2.14 Dilution Air — Ambient air which is passed through filters to stabi-
lize the background hydrocarbon concentration and which  is used to dilute
the vehicle exhaust.
    2.15 Dilution  Factor — Based  on stoichiometric equation for fuel with
composition CH1SS, the dilution factor is defined as:
                      _ 13.4 _
                      CO2 + (HC + CO) x  10-4
where CO2 is  equal to the concentration in  dilute  exhaust sample in mole
percent, HC in ppm carbon equivalent, and CO in  ppm corrected for water
vapor and CO2 extraction.
    2.16 Dilution  Ratio — The  ratio of  CVS  volume to exhaust volume,
usually found  by dividing the undiluted  exhaust CO.2 concentration by the
dilute  CO2 concentration.
     2.17 Driver Aid— An instrument used  to guide the  vehicle driver  in
operating the vehicle in accordance with  the specified acceleration, decelera-
tion, and cruise operating modes of a specific driving procedure.
    2.18 Exhaust  Emissions — Substances  emitted  to the  atmosphere from

-------
25.106
any opening  downstream from the exhaust port of a motor vehicle  engine.
    2.19 Fifth  Wheel—A calibrated  wheel, axle and tachometer generator
assembly that can be used  to determine  the true speed of the vehicle (by
towing the wheel  assembly), or true speed of the dynamometer rolls (by
permitting the  rolls to drive the fifth  wheel assembly).
    2.20 Filter Cell—That  portion of the NDIR instrument which  is  tilled
with a particular gas in order to reduce interference signals.
    2.21 Flame loni/alion Detector (FID)—A hydrogen-air tlame detector
that  produces a signal proportional to the mass  How rate of  hydrocarbons
entering the Maine per unit  time.
    2.22 Hang-Up—The absorption-desorption of sample  (mainly higher
molecular weight hydrocarbons) from the  surfaces of the sample system that
can cause  instrument response delay and lower concentration at the analyzer.
followed by higher readings in subsequent tests.
    2.23 Heat  Exchanger—An air-to-air or  air-to-water heat exchanger.
which is used  to  control the temperature of  the dilution  air-exhaust gas
mixture.
    2.24 Horsepower
  '-'.24.1 ABSORBED HORSEPOWER—Total horsepower absorbed by the  absorp-
tion unit of the dynamometer and  by the  frictional components of the dyna-
mometer.
  2.24.2 ABSORBED HORSEPOWER AT 50 MPII (80.5 KM/H)  ROAD LOAD—The
dynamometer setting values for various inertia  weight vehicles published in
the* Federal Register.
  2.24.3 FRICTIONAL  HORSEPOWER—Horsepower absorbed by  the  frictional
components of  the dynamometer.
  2.24.4 INDICATED HORSEPOWER—Horsepower values  indicated  by  the
horsepower meter of the dynamometer.
  J.24.5 INDICATED HORSEPOWER AT 50 MPII (80.5 KM/H)  ROAD LOAD—The
dynamometer setting values, determined by calibration,  that  correspond to
the dynamometer setting values published in the Federal  Register.
    2.25 Inertia Weights—A series of rotating disks used on a chassis dyna-
mometer to simulate to the nearest 125, 250, or 500 Ib (57, 113, or  227kg)
increments of the test weight of a vehicle  during accelerations  and decelera-
tions.  The inertia weights have no effect during steady states.
    2.26 Lagrangian Fit—A computer technique used to  interpolate polyno-
mial curves generated from  a set of data points (calibration points).  ;V data
points are  required to  generate a  curve  to N —  I  deg.  A feature  of this
technique is that the interpolated curve goes through each data  point exactly.
    2.27 Laminar Flow Element (LFE)—A flow rate measuring device that
has a  linear relationship between How rate and pressure drop.
    2.28 Light-Duty Vehicle—A motor vehicle designed for transportation of
persons or property on a street or  highway and weighing 6000 Ib (2722 kg)
gvw or less.
    2.29 Loaded Vehicle Weight—The curb weight of a light-duty  vehicle
plus 300 Ib (136kg).
    2.30 Mixing Device—A device that is used in the main flow stream of a
CVS  to promote mixing of the exhaust gas with the dilution air.
    2.31  Mode—A particular operating condition (for example, acceleration.
cruise, deceleration, or idle)  of a test cycle.
    2.32 Nondispersive Infrared (NDIR) Analyzer—An  instrument to de-
termine carbon  monoxide, carbon dioxide, nitric oxide, and hydrocarbons in
exhaust gas.  Now  primarily being used  lor carbon  monoxide and  carbon
dioxide determinations.
    2.33 Normalizing Gas (Span Gas)—A single calibrating gas blend rou-
tinely used in calibration of each analytical instrument.
    2.34 Optical Filter—That portion of the NDIR instrument which elimi-
nates  wavelength regions where interference signals are obtained.
    2.35 Oxides of Nitrogen—The sum total of the nitric oxide and nitrogen
dioxide in a sample expressed as nitrogen dioxide.
    2.36 Ozonator—An electrical  device  that generates ozone from  oxygen-
or air.
    2.37 Parts  per Million Carbon—The mole  fraction of  hydrocarbon
measured  on  a  methane equivalence basis.
    2.38 Polynomial Fit—A technique of generating a calibration curve from
a set  of points.
    2.39  Positive Displacement Pump—A CVS blower, gas pump,  or con-
stant  displacement pump that delivers a metered amount of air  per revolution
measured  at inlet conditions.
    2.40 Probe—A sample  line inserted into the exhaust  stream of a vehicle
or engine in such a manner as to obtain a homogeneous or well-mixed exhaust
sample.
    2.41 Reference  Cell—That portion  of the NDIR  instrument  that  is
usually filled  with  air (sometimes nitrogen) and provides the reference signal
to the detector.
    2.42 Remote Filter Box—Particular CVS design that has the dilution air
filters and mixing chamber housed in a separate cabinet which can be  located
close  to the tailpipe of the test vehicle.
     2.43 Sample Cell—That portion of the NDIR instrument which contains
the flowing sample gas.
     2.44 Stratification—Variation in concentration of a sample stream when
samples are taken at different points on a cross section  of the mixed  CVS
stream just ahead of the CVS positive displacement pump.
     2.45 Tailpipe Pressure—The static pressure measured  at the tailpipe
when a CVS is connected to a test vehicle.
  3. Tett Facilities and Equipment
     3.1 Sampler—CVS systems can exist in a variety of physical configura-
tions, but all of them permit measuring emissions of vehicles.
  3.1.1  BASIC EQUIPMENT—The principal component of a CVS is either the
positive displacement pump (PDF) of the older models or the critical flow
venturi (CFV)  of more recent  designs.  The  positive displacement pump
consists of a pair of symmetrical  rotating, two-lobe impellers driven in oppo-
site directions and encased by a housing. A critical  flow venturi CVS has a
CVS compressor unit that is used in conjunction with the critical flow venturi.
Fig.  1 shows  a sketch of a CFV-CVS.
     3. I.I.I A dilution air filter system consisting of a paniculate (dust) filter,
a charcoal filter, and  a second  paniculate filter  which  removes airborne
particles, stabilizes hydrocarbons, and traps charcoal particles.
     3.1.1.2 A flexible coupling to the tailpipe  of the test  car  brings in undi-
luted exhaust gas to the mixing  chamber.
     3.1.1.3 A mixing chamber combines the  automotive exhaust from the
test car and the dilution air into a homogeneous (nonstralilicd) mixture.
     3.1.1.4 A heat exchanger is used to control the temperature of the ex-
haust gas dilution  air  mixture.  The  heat exchanger should be capable of
controlling the  temperature of the dilute exhaust gas ±; 10°F  (5.6°C) during
testing. In some models of CVS, a temperature controller regulates both the
flow of cooling water or hot water (from a hot water heater) through the heat
exchanger  to control mixture temperature. In other  models of CVS, the
dilution air is preheated so that the temperature controller regulates the flow
of cooling water through the heat exchanger in order to control the mixture
temperature.
     3.1.1.5 A secondary heater  system maintains  the heat  exchanger at  a
temperature to  prevent  water condensation.
     3.1.1.6 A sampling system  transfers the exhaust-air mixture from the
positive displacement pump inlet to  the bag  at a constant  flow rate. The
minimum sample  flow rate  should be 10 ft:1/h (0.28 m3/h).  Each sampling
system consists  of fiberglass filter, a diaphragm type pump,  a How  control
valve, and a flow  meter or other gas measuring device. All of the surfaces in
contact with the sample air or  air-gas mixture are stainless steel or other
nonreactive material.
     3.1.1.7 A similar sampling system collects dilution air from a point just
downstream of  the air  filter and transfers it  to a separate bag.
     3.1.1.8 An evacuation and purge pump to remove the excess sample from
the bags and purge the bags with clean air.
     3.1.1.9 A set of bags (sample and background) and appropriate controls
is needed  for each of the test phases.
  3.1.2  SUPPLEMENTARY EQUIPMENT—In addition to  the above basic equip-
ment, the following items can be added  for operating convenience:
     3.1.2.1 A muffler located  after the CVS pump  to reduce the noise.
     3.1.2.2 A four-speed motor, transmission, or other suitable  means for
driving the positive displacement pump will  permit  a  choice of different
dilution ratios.
     3.1.2.3 An optional remote control operating station  containing the
counter, the operations logic module,  and  the various control function
switches and indicator lights that permit convenient operator control at  a
distance from the CVS  console.
     3.1.2.4 Optional modal analysis at the analytical bench during the filling
of the bag is  made possible through the use of a separate  sampling probe(s).
One probe is used if continuous modal analysis is conducted using undiluted
exhaust.1 The second probe in this case is used to monitor  diluted CO.j which
is used as a tracer gas to determine engine flow. Tail pipe sample should either
be returned to the CVS bulk stream if the amount withdrawn is a significant
fraction of total exhaust flow (greater than l'7<), or the loss in tail pipe sample
should be corrected mathematically.
     3.2 Analysis  Instrumentation—Bag Analysis
  3.2.1  SCHEMATIC—Fig. 1 is a sketch of the sampling and analysis train that
is a typical flow schematic for the bag analysis of engine exhaust using the
CVS.
  3.2.2  COMPONENT DESCRIPTION—The following components are* suggested
for the CVS bag sampling and analytical systems for the analysis of carbon
monoxide (CO), hydrocarbons (HC), nitrogen  oxides (NOX), carbon dioxide
(CO2), and oxygen (O2):
  'Two probes are required if continuous modal analysis is conducted using undiluted
exhaust.

-------
                                                                                                                                          25.107
                                                      FIG.  t-GFV-CVS SAMPLER UNIT
    3.2.2.1 NDIR analyzers for measurement ol CO and CO., with cells of
appropriate length for concentration ranges being measured. Typical ranges
are shown  in Table I.
    3.2.2.2 Chemiluminescent  (CL) NO analyzer or equivalent NDIR NO
analyzer are both equipped with a. bypass and NO2 to  NO converter for the
measurement of NOS  with concentration range selection as shown in Table  1.
    3.2.2.3 FID for measurement of HC. The instrument employed should be
capable of measuring HC for ranges shown in Table 1.
    3.2.2.4 Oxygen analyzer for measurement of O2 with range of measure-
ment  as shown in Table 1.
    3.2.2.5 Values V,2 used to direct the sample or purge air to the analyzers.
    3.2.2.6 Valves V,,  V4, Vg (optional).  V9, and  V,0  used  to  direct the
sample, zero gas, or span gas streams to the analyzers.
    3.2.2.7 Filters F, and  F.2 for removing paniculate materials  from the
sample  prior to analysis. A  glass fiber filter of at  least 7 cm diameter  is
suitable.
    3.2.2.8 Pumps P, and P2 to move the sample through the system. Pumps
should have stainless steel or aluminum chambers with diaphragms and valves
made from or covered with an inert material, such as Teflon. Free air capacity
should be approximately 40 ft3/h (1.1 nv'/h). Pumps P., for bypass How of
Chemiluminescent analyzer and vacuum pump P4 (optional depending upon
the design of the Chemiluminescent analyzer) for evacuation  of the Chemi-
luminescent reactor chamber.
    3.2.2.9 Needle valves N,, NH, N7, and N,, to regulate sample gas flow to
the analyzers.
    3.2.2.10 Needle valves N2, N5, N8, and N12 to regulate span gas flow to
the analyzers.
    3.2.2.1! Optional valve V9 used to direct CO2 span gas through the
water bubbler for checking the performance of drier and absorber system or to
check the  H2O and  CO2  interference  rejection  characteristics of the CO
analyzer. Needle valve N20 is used to regulate CO2 flow.
    3.2.2.12 Needle valves N3, N6, N9, N13, and N)5 to regulate zero gas flow
to the analyzers.
       TABU 1—TYPICAL LOW RANGES FOR  ANALYSIS OF HC, CO, CO,,
             NO,, AND O, IN SPARK IGNITION ENGINE EXHAUST


HC
CO
1975
1976
CO,
Dilute CO,
02
Ranges
CVS Bag Sample
0-30 ppmC
0- 1 00 ppm
0-250 ppm
0-10 ppm
0-2.0%
—
0-21%
Undiluted Exhaust Gal
0-500 ppmC
0-0.3%
0-2500 ppm
0-250 ppm
0-15%
0-5%
0-10%
     3.2.2.13  Flow meters FL,, FL2, FL3, and FL4 to indicate span gas, zero
gas,  and sample flow to the analyzers.
     3.2.2.14  Water trap T,, if necessary, to partially remove  water and a
valve N14 to  allow the trap to be drained.
     3.2.2.15  Optional2 sample conditioning columns CR, and CR2 contain-
ing ascarite to remove CO2 from the CO analysis stream, and WR, and VVR2
containing indicating CaSO4 or indicating silica gel to remove the remainder
of the water. Equivalent drying techniques such as diffusion driers may be
used.
     3.2.2.16  Optional valves V6 and V7 to permit switching from exhausted
absorbing columns to fresh columns.
     3.2.2.17  Optional water bubbler W, to allow saturation of CO, span gas
to check the  efficiency of the absorbing columns in the CO system.
     3.3 Analysis Instrumentation—Modal Analysis (Undiluted Exhaust Gas)
  3.3.1 GENERAL—Fig. 3 is a schematic drawing of the sampling and analysis
train that is  recommended  for the modal analysis of spark ignition engine
exhaust using the CVS. The system  is very similar to that required  for bag
analysis, with the exception that water traps are required on all instrument
sampling streams and an additional CO2 analyzer is required. In addition,
instruments  of only approximately '/,„ the sensitivity of  those  used for bag
analysis are needed. This system is based upon measuring continuously undi-
luted exhaust gas concentrations of HC, CO, NO,, and CO2 and the diluted
exhaust CO2 concentration.
  The undiluted and diluted exhaust CO., concentrations are used to calcu-
late a dilution factor which, in conjunction with the total diluted volume, can
be used to calculate the vehicle exhaust volume. With the calculated exhaust
volume and  the undiluted exhaust concentrations, the modal mass emissions
of each pollutant can be calculated as described in paragraph  5.2.2.
  3.3.2 COMPONENT  DESCRIPTION—The  following  components are  recom-
mended for the analytical systems for the modal analysis of CO,  HC,  NO.,
CO2, and O2.
     3.3.2.1 NDIR analyzers for  measurement  of CO and CO2 with  cells of
appropriate  length  for the  concentration ranges being  measured.  Typical
ranges are shown in Table 1.
     3.3.2.2 The CO2 analyzer for the measurement of CO2 in the diluted
exhaust stream can be modified to the extent that  the reference cell  is replaced
with a second sampling cell through which dilution air  is passed during
sampling. This feature will automatically correct the measured CO2  in the
diluted exhaust  for the amount of CO2 in the dilution air.
     3.3.2.3 Chemiluminescent (CL) NO analyzer equipped with a bypass
                                                                            2The criteria for CO interference by CO2 and water is given in the Federal Register,
                                                                          Vol. 39, No. 101, May 23, 1974: "A CO instrument will be considered to be essentially
                                                                          free of CO2 and water vapor interference if its response to a mixture of 3% CO2 in Nz,
                                                                          which has  been bubbled through  water at room temperature (68-86° F), produces an
                                                                          equivalent  CO response, as measured on the most sensitive CO range, which is less than
                                                                          1% of full scale CO concentration on instrument ranges above 300 pptn CO or less than
                                                                          3 ppm on instrument ranges below 300 ppm CO."

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25.108
          FIG. 2-BAG SAMPLING AND ANALYSIS TRAIN

and a NO; 10 NO convener for the measurement of NO, with the concentra-
tion range selection as shown  in Table  I.
    3.3.2.4 FID for measurement of HC. The instrument should be capable
of measuring HC for  the ranges shown in Table  I.
    3.3.2.5 Oxygen analyzer for measurement of O., with range of measure-
ment'shown in Table I.
    3.3.2.6 Valves V, and V,., used  to direct (he sample of purge air to the
analyzers  or to purge air to the blowout traps.
    3.3.2.7 Valves V,, \\, V,,, V10. V14, and V,,, used to direct the sample.
zero gas. or span gas streams to the analyzers. Valve V4 is used to direct the
span gas to the O.j sensor.
       FIG.  3—MODAL SAMPLING AND ANALYSIS TRAIN
     3.3.2.8  Filters F,,  F.,. K.,. and F,  for removing the  paniculate  from the
sample prior to  analysis. A class tiber typo of at  least  7 cm in diameter is
suitable.
     3.3.2.9  Pumps P,, P.j, P.,, and P., to move the sample through the system.
Pump P5 for bypass How of the chemiluminescent analyzer and vacuum pump
PU (optional dependent on  design of chemiluminescent analyzer) for evacua-
tion of the chemiluminescent reactor chamber. Pumps should have stainless
steel or aluminum chambers with diaphragms and valves made from  or
covered with an inert  material,  such  as Teflon. Free air capacity should  be
approximately 40 fr'.'h (1.1 nr'/h).
     3.3.2.10  Needle valves N.J, N;l. N,,,. N,._,, N,-, and N1!t to regulate sample
gas flow to the analyzers.
     3.3.2.11  Needle valves N,. Nrt, N,,. N,a. arid N.,., to regulate span gas flow
to the analyzers.
     3.3.2.12  Optional valve  V'.,, used to direct CO., span  gas  through the
water bubbler  for checking  the performance  of  the absorbers in the CO
analyzer stream. Needle valve N,, (optional) is used to regulate CO._,  flow.
     3.3.2.13  Needle valves N5, N7. N,,. N,v N;,,, and N.j, to regulate zero gas
flow to the analvzers.
     3.3.2.14  Flow meters KM,.  KM... KM.,. KM.,, KM,,,  and KM(i to indicate
span gas,  zero gas. and sample flow to the analyzers.
     3.2.2.15  Water traps T,, F... and T-, to partially remove  water and valves
N.,,. N1.,,,.  and N.JI; to  allow the  traps  to be drained.
     3.2.2.16 Optional sample conditioning columns OR, and CR.j containing
ascaritc in remove CO.,  from the CO analysis stream,  and WR,  and WR,
containing indicating CaSO, or  indicating silica gel to remove the remainder
of the water. Ascaritc produces water when it removes CO..  from the stream.
Equivalent  drying techniques such as  diffusion driers may  be used.  The
volume of the conditioning columns must be sufficient to be effective for the
duration of the lest. Some operational ranges  for continuous  analysis may not
require  water and CO., removal. Some  new CO instruments do  not  have
water or CO., response.
     3.3.2.17  Optional valves V,,,  and  V'.,0  to permit  switching  from the
exhausted absorbing columns to fresh columns.
     3.3.2.18 Optional water bubbler W, to allow saturation of CO.. span gas
to check the efficiency of the absorbing columns in  the CO system.
     3.3.2.19 Needle  valves N,,   NB,  N,,,  and  N|(i to  regulate ihc  bypass
sample Mow.
     3.4 Instrument Operating Procedures—Follow the instrument  manufac-
turer's start-up and operating procedure for the particular type instrument
being used. In addition, the following minimum calibration and instrument
checks should be included.
   3.4.1  INITIAL—The  following  instrument checks should  be  accomplished
prior to making emission measurements  with the  instruments:
     3.4.1.1  Optimise h'lD Resptmse
   (a) Set burner fuel and air settings  as  prescribed by the  manufacturer.
Present burner  fuel  composition  now recommended is tiO'v-  He,  40r'i  H...
However, best composition for burner fuel is now being investigated. Ignite
the  burner and set  sample flow. Wait until the  analyzer  stabilizes before
proceeding. Optimize the  KID  as suggested  in SAK Procedure J25-I (June,
 1971).
   (b) Determine the optimum  burner  fuel flow for maximum response. A
blend of 60'/< He and 40" H., is  recommended for use as the burner fuel. The
use of other fuels could produce  a correlation problem.  Introduce propane in
N.j at a  concentration level  of  approximately 300 ppmC for undiluted gas
analysis and propane in air for bag  analysis.  Vary the burner fuel flow to
obtain ihc peak response. Normally, there is a plateau  in the region of peak
response.  Select a flow in  this region which  results  in  the least variation in
response with minor  fuel flow variations.
   (c) Determine optimum airflow. Set the burner fuel flow  as determined in
paragraph 3.4.l.l(b)  and vary airflow to obtain maximum response. If the
airflow  is too high, excessive noise may result.
   (d) If the airflow is significantly different from  that used  in paragraph
3.4.1.1(b), repeat step (b) with  the new  airflow.
     3.4.1.2 Determine Oxygen Response of FID Analyzer—Variations in the oxy-
gen content  of the sample can  affect the FID  response. This  effect must be
determined and minimized.
   (a) CVS bag analysis
     (I) Set  flows as determined in paragraph  3.4.1.1 and ignite the burner.
Wait for stabilization.  Normally, the burner is operated  continuously to avoid
the  stabilization problem.
     (2) Zero the analyzer on HC  free air.
     (3) Determine the  oxygen  response by introducing propane  gas  at a
concentration of approximately  30 ppmC in the following diluents:  100% N2,
95% N2/5% O2, 90%  N,/IO% O,, 85% N,/15% O,,  and 100% air.
     (4)  Using the propane in the air gas as the baseline for  no O2 correction,
plot a curve of the  oxygen  correction  factor versus the percent O2 in the
sample:

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                                                                                                                                          25.109
                 O2 correction factor = 1.0 —
(A - B)
   B
                                                                                                                     CHEMILUMINESCENCE »N»LY2ER
where: A = HC response in N2/O2 blends
       B = HC response in air
    (5) Check the effect of O2 using a propane concentration of 50 ppmC. If
it is significantly different from the 30 ppmC correction data, establish a curve
and apply the O2 correction on a prorated basis as a function of HC concen-
tration.
    (6) If the O2 correction factor is less than 0.96 over the normal O2 range
encountered in  CVS sampling, see paragraph 3.5.2.
    (7) It is recommended that a different detector be obtained if the oxygen
correction factor is  less than 0.90 for  the  O2 range found in CVS samples.
  (b) Modal Analysis—Undiluted Exhaust Gas
    (1) Set flows as determined in  paragraph 3.4.1.1 and ignite  the burner.
Wait for stabilization. Normally, the burner is operated continuously  to avoid
the stabilization problem.
    (2) Zero the analyzer with N2.
    (3) Determine  the oxygen response by  introducing propane gas at  a
concentration of approximately 300 ppmC in the following diluents: 100% N2,
95% N2/10% O2, 85% N,/15% O2, and 100% air.
    (4) Using the propane in N2 (0% O2) as the baseline for no O2 correction,
plot a curve of the oxygen correction factor versus  the  percent O2 in the
sample, where:
                          HC response with propane in 100% N,
        O, corr factor =
                         HC response with propane in O2 blends
    (5) If the O.j correction factor  is greater than  1.05 over the range of
0-10% O2, see paragraph 3.5.2.
    (6) It is recommended that a different detector be obtained if the oxygen
correction factor is greater than 1.10 for the O2 range found in the undiluted
exhaust gas samples.
    3.4.1.3 Dtlermint Linearity of FID Response
  (a)  Set up the FID as determined in paragraphs 3.4.1.1 and 3.4.1.2. Set the
sample flow rate at a low  value (approximately 5 ml/min) consistent with
good signal to noise ratio.
  (b)  Using propane in air, or N2, vary the concentration of HC over the
expected HC range. If the response is linear, a sample linear calibration factor
can be used. If the response is not linear, prepare a calibration curve.
    3.4.1.4 Optimize Performance of ND1R—After adjusting the analyzers for
optimum performance using the manufacturer's recommended procedures, a
calibration curve must be generated for the ranges of the instrument that will
be used.  All emission measuring instruments are comparative devices. The
generation of the calibration curves  using standard gases (paragraph 3.5.1)
should be as  accurate  as  possible. Since  many analyzers  are connected to
computers, a  variety of curve-fitting techniques are being used.  No specific
technique will  be recommended  here. Polynomial and Lagrangian  curve
fitting techniques are widely used. It is recommended to examine carefully an
accurate  plot of  the calibration curve  to verify that  a smooth curve was
generated, rather than  a curve  that has  only high correlation at the data
points.
    3.4.1.5 Optimize Performance of Ctiemitummescence  NO Analyzer—Using the
manufacturer's  recommended  procedures, adjust the  analyzer for optimum
performance.  In addition, determine the efficiency of the  NO2 to NO con-
verter, at the converter temperature recommended  by the manufacturer,
using the flow system shown schematically in Fig. 4. A  suggested procedure  is
given  in Appendix A.
  If the converter efficiency is below 90%, the converter temperature should
be increased and the efficiency rechecked. Converter temperature should be
set at a minimum required for near  100% conversion efficiency.
  Care must be used to prevent condensation due to pressure buildup  in the
NO, sample train between the sample pump and the analyzer. This has been
found to be a critical area of the NO, sample train, since condensation causes
a lowering of the measured NO, concentration and, therefore, an incorrect
NO, emission measurement.
  3.4.2 MONTHLY—The following checks  are to be made  monthly^or more
frequently if there is any doubt  regarding the accuracy of the analyses.
    3.4.2.1 Calibrate  the  NDIR analyzers using the same gas flow rates as
when  sampling exhaust.
  (a)  Allow 2 h  warmup of analyzers.
  (b)  Tune analyzer.
  (c)  Set zero and span using prepurified N2 and the 100% range calibration
gas.
  (d)  Recheck zero and repeat step 3.4.2. l(c), if necessary.
  (e)  Calibrate each analyzer with calibrating gases that are approximately
15,  30, 45, 60,  75, and  90% of each range used.  The concentration of the
standard gases should be known with at least ±2% accuracy. If the analyzer
proves to be non-linear, use an eight point calibration with a set of calibration
                                                       COMPONENT DESCRIPTION
                                                       Ci  O> supply connection
                                                       Ci  NO SUPPLY CONNECTION
                                                       C,  CHEMILUMINESCENCE ANALYZER CONNECTION
                                                       MV,  OXYGEN SUPPLY FLOW CONTROL VALVE
                                                       MV,  NITRIC OXIDE SUPPLY FLOW CONTROL VALVE
                                                       Vi  ON OFF FLOW SOLENOID VALVE
                                                       V.  CONVERTER BYPASS VALVE
                                                       FM,  FLOWMETER  TO MEASURE 0, FLOW RATE
                                                       FM,  FLOWMETER  TO MEASURE NO FLOW RATE
                                                       NO SUPPLY  150-250 PPM NO IN NITROGEN
                             FIG.  4—FLOW   SCHEMATIC   OF  CONVERTER
                                                      ANALYSIS SYSTEM
EFFICIENCY
                             gases spread approximately uniformly over the analyzer range in question.
                               (f) Compare values with previous curves. Any significant change reflects
                             some problem in the system. Locate and correct the problem and recalibrate.
                                 3.4.2.2 Check FID analyzer O., response and  HC response.
                               (a) Ignite the burner and then  set the fuel,  air. and sample flow  rates as
                             determined in  paragraphs 3.4.1.1 and 3.4.1.2.
                               (b) Introduce HC free air zero gas (CVS bag analysis) or N2 (Modal-undi-
                             luted exhaust gas analysis) and zero analyzer.
                               (c) Check O2 effect on  the response by introducing the calibration gases of
                             propane in air, propane in N2, and propane in 90% No/ 10'tf O;,.
                               (d) Compare the O2 response values with the previous curves. Any signifi-
                             cant change (:± 10%) indicates a change in the  burner operating characteris-
                             tics. Check the burner system and measure the Hows.  If the change in the
                             response cannot be resolved, establish a new O2 response  curve as per para-
                             graph 3.4.1.2.
                               (e) Check the calibration curve or response data as per paragraph 3.4.1.3.
                                 3.4.2.3 Calibrate chemiluminesccnt analyzer using same flow  rates as
                             when sampling exhaust.
                               (a) Set  the  sample flow and oxygen  flow to the recommended settings.
                               (b) Turn the ozone generator on and allow a 10 min warmup period.
                               (c) Using nitrogen, zero the meter on the most sensitive range or the  range
                             to be used by  means of the dark current suppression adjustment.
                               (d) Set the span, using  IOO'/! range calibration gas on the range to be used.
                               (e) Calibrate the analyzer with gases blended in N.j that are approximately
                             25, 50,  75, and 100% of the range being used.
                               (f) Check the  values with  the previous curves.  Any significant change
                             reflects some problem in  the  system. Locate and correct the problem and
                             recalibrate.
                               (g) Caution. The correct standby position for the NO, converter is depend-
                             ent  on  the converter type. See manufacturer's  instructions.
                               (h) Caution. Some NO2 to NO converters can be rendered useless for  many
                             hours if they are allowed to sample exhaust gas (even momentarily) from over
                             rich vehicles where high   levels of CO,  low levels of O2, and  free H2 are
                             produced.
                               3.4.3 WEEKLY—Check  the  converter  of the chemiluminescent  analyzer
                             using the procedure outlined  in paragraph  3.4.1.5.
                               3.4.4 DAILY—Prior to daily testing carry out the  following:
                                 3.4.4.1 NDIR Analyzers—Normally, power is left on the NDIR analyzers
                             continuously. Only the chopper motors are turned off. In some cases, more
                             dependable performance has been achieved by leaving the chopper motors on.
                               (a) Zero on  prepurified N2.
                               (b) Introduce span gas  and set  the gain to match the calibration curves.
                             Use the same flow rate for calibration, span gas, and exhaust gas to  avoid
                             correction for the sample cell pressure change. Use span gas having a concen-
                             tration  of the constituent  being measured that  will result  in 75-95% of full-
                             scale deflection.  If the  gain  has shifted significantly, check the tuning; if
                             necessary,  check the calibration.
                               (c) Check nitrogen zero and repeat steps 3.4.4.1(a) and 3.4.4.1(b), if neces-
                             sary.
                               (d) Repeat steps 3.4.4.l(a)  through 3.4.4. l(c) prior to each exhaust  gas
                             analysis.
                               (e) Span and zero should be rechecked after bag measurements.

-------
25.110
    3.4.4.2 FID Analyzer
  (a)  Ignite the burner and then set the fuel. air. and sample flow rales as
determined in paragraphs 3.4.1.1  and 3.4.1.2.
  (b)  Introduce zero gas (HC-free air  lor CVS analyzers. .V, lor undiluted
exhaust gas analyzers)  and zero analyzer.
  (c)  Introduce HC span gas (propane in HC-free  air for CVS analyzers.
propane in No for undiluted exhaust gas analyzers) of appropriate concentra-
tion to result in a response of at least 50'v of full-scale on the range anticipated
for  use. If the calibration  curve  and span value  disagree adjust  the  span
potentiometer of the FID. Sample How for zero and span must be the same as
that used  for analyzing exhaust sample.
  (d)  Repeat  steps 3.4.4.2(a)  through  3.4.4.3(c) prior to each  exhaust gas
analysis.
  (e)  Span and zero should be rechecked after bag measurements.
    3.4.4.3 C/iemiluminrsrent Analyzer—Normally power is left on continuously.
Operate converter in standby  mode as recommended by the  manufacturer.
Vacuum pumps arc normally kept on continuously on those model analyzers
using  vacuum pumps.  The ozonator should not  be left on continuously for
safety  reasons. Vacuum  pump and ozone problems can be  minimized by
replacing  the pump oil with pertluorinated polyether fluid.
  (a)  Turn on the sample  pumps.
  (b)  Set  CX (in some models air is used) and sample Hows using nitrogen.
  (c)  Turn on ozone generator and allow a 10 min warmup.
  fd)  With the converter in the NO mode, adjust  the dark current suppres-
sion to zero  the meter on the  most sensitive range or the range to be  used.
using prepunlied N...
  (el  Introduce span gas and set  gain to match the calibration curves. Use a
span gas having an NO concentration (hat will result  in 73-95''''  of full-scale
deflection.
  (f)  Check  dark  current  suppression  and  repeat steps 3.4.4.3(dl and
3.4.4.3(e)  if necessary.
  (g)  Span and zero should be rechecked after bag measurements.
    3.4.4.4 Oxygen Analyser
  (a)  Introduce oxygen-free nitrogen and set zero.
  (b)  Introduce air and set O2 span. This is usually done concurrently when
setting the zero on the FID analyzer.
  (c)  Sample flow  for zero and  span must be the same  as that used when
analyzing  exhaust  gas samples.
    3.5 Supplementary Discussion
  3.5.1  CALIBRATION GASES—There are several suppliers of calibration  gases
in the ranges used in this procedure.  These can be obtained wiih an analysis
accuracy of ±2'^ or better. Slated gas analysis  accuracies should be explicitly
defined in terms of traccability to  NBS standard reference gases or applicable
gravimelric standards.  It is recommended  that all working gases be renamed
using NBS standard reference  gases or  in-house primary reference gases. If a
reference gas cylinder value does not fall on a smooth calibration curve, then
that cylinder must  not be used.
  The CO and CO2 gas can be purchased as a  mixture in nitrogen. NO
calibrating gas should be diluted  with oxygen-free nitrogen and must not be
mixed either with CO or CO2. Propane calibrating gases  are purchased with
HC-free air  as the  diluent  for use in CVS bag analysis and with N2 as the
diluent for use in undiluted exhaust  gas analysis.
  Zero gas impurity concentration should not exceed 1 ppm for HC, 1 ppm
for CO. O.I  ppm for NO,  400 ppm (0.04%) for  CO2, and 3 ppm for H2O.
  3.5.2 REDUCING THE OXYGEN EFFECT ON RESPONSE—The oxygen correction
for FID should be reduced to attain the limits described in paragraph 3.4.1.2.
The oxygen effect on response for a particular FID burner  design may depend
upon  (a) the type of burner fuel  used, for example H2, 40% H2/60% N2, or
40% H2/60% He; (b) on the sample flow rate into the burner; and (c) the air
and fuel rate to the burner.
    3.6 Tailpipe Connections—To obtain a good constant volume sample of
exhaust gas it  is imperative that no leakage, either into or out of the sampling
system, occur at the tailpipe connection between the vehicle and  the  CVS
sampler. The CVS sampler must  be provided  with dual  inlets to accommo-
date vehicles with dual exhaust systems. When  a vehicle with a single exhaust
is being tested,  the second sampler inlet must be tightly capped to prevent
leakage.
  Piping between the sampler and the  vehicle  should be kept to a minimum
length and be of adequate diameter. (See Section 4  for more detail on this
subject.) The actual connection between the vehicle tailpipe and the flexible
tubing of  the  CVS can be  made  in one of two ways:
    (a) A flanged fitting such as a Marmon coupling. One end of this cou-
pling  is welded to the flexible  piping from the CVS and  a mating section  is
welded to the exhaust  pipe(s)  of each vehicle  to be tested.
    (b) A silicone rubber boot clamped to the  exhaust pipe and  inlet plumb-
ing to the CVS.
  The first  method, a flanged fitting, should be used  whenever possible.
However,  when fittings cannot be welded to each vehicle to be tested, the
silicon boot alternative has to be used. The main drawback of the silicone boot
is that the  hot exhaust gas causes rapid deterioration of the silicone. When
vehicles with advanced control devices are tested, the very hoi  exhaust gases
produced by these systems may cause the boot to crack internally after a single
test.
    3.7 Chassis Dynamometer
  3.7.1  PROCEDURE FOR  DYNAMOMETER ABSORBED  HORSEPOWER CALIBRA-
TION — The  following procedure  describes  one method for determining the
absorbed horsepower of a chassis  dynamometer. The measured absorbed
horsepower includes the  dynamometer frictional  horsepower as well as the
power absorbed  by the power absorption  unit. The dynamometer is driven
above the lest speed range to 60 mph (96 km/h). The device used to drive the
dynamometer (in most cases a vehicle) is then  disengaged from the dyna-
mometer and the  roll(s)  allowed to coast down.  The kinetic  energy of the
system is dissipated by the dynamometer friction and absorption unit.  This
method neglects the variations in roll bearing friction due 10 the drive axle
weight  of ihe vehicle  and also neglects  the  variations  in friction  due to
different inertia weights.  The difference in coastdown time of the free (rear)
roll relative to the drive  (from)  roll may be neglected in the  case of dyna-
mometers with paired rolls.
    3.7.1.1 Equipment
  (a)  Fifth wheel, tachometer generator, or other device to measure the speed
of the front roll.
  (b) Hydraulic jack or  other equipment  to lift  vehicle's  drive wheels  from
ihc rolls.
  (c)  Stop watch or other liming device to measure the lime ii  lakes the rolls
speed to decrease from 55 lo 45 mph (88.5 lo  T1A km/h).
  id) Pair of chocks, vehicle tie-downs, and other safely devices  used lo assure
safe operation of a vehicle on  the rolls.
    3.7.1.2 Preparation
  (a)  Place the vehicle on the dynamometer rolls and set chocks  against the
front  wheels. Tie-downs  should  be  slack enough  to allow the  vehicle to be
lifted  from  the rolls.
  (b) Verify the calibration of the fifth wheel,  tach generator, or other speed
monitoring equipment.
  (c)  Position the lifting device at  the rear of vehicle.
  (d) Place the  lift  pads under the rear  bumper, adjacent to the  bumper
brackets.
  (e)  Practice lift technique in disengaging the rear wheels  to develop a
familiarity  with  the lifting device's  response.
  (f)  When  satisfied, raise the lift  pads until they are in contact with the
bumpers so that there is sufficient tension to keep the lift  pads  in place  until
ready to use.
  (g)  Set dynamometer inertia 10 4000 Ib (1816kg) or to the more common
weight class to be tested.
    3.7.1.3  Test  hocedure
  (a)  Drive the  dynamometer with the lest vehicle lo 50 mph (80.5 km/h).
  (b) Adjust the dynamometer power absorption unit to an indicated 2.5 hp
(1.9kW).
  (c)  Accelerate the dynamometer  test vehicle to 60 mph (96 km/h). At this
point, disengage the drive wheels from the rolls by means of the lifting device.
  (d) Record the time for the dynamometer to coast down  from 55 to 45 mph
(88.5  to 72.4 km/h).
  (e)  Repeat steps 3.7. l.3(c) and 3.7.l.3(d) two  more times.
  (f)  Calculate  an average from ihe three coastdown times.
  (g) Repeal steps 3.7. 1.3(a) through 3.7.1.3(0 for 5.0, 7.5,  and  10.0 indicated
hp  (3.7, 5.6, and 7.4 kW) and calculate the average coastdown limes for each.
    3.7.1.4 Calculations — Calculate  actual absorbed road  horsepower from:
               HP«, = -^
(V* _
                        2 32.2
                                   550(
                                              0.06073
                                                   /
where: Wi  = equivalent  inertia, Ib
        C,  = initial velocity, ft/s (55 mph = 80.67 ft/s)
        Cj  = final velocity,  ft/s (45 mph = 66.00 ft/s)
         (  = elapsed  time for rolls  to coast down from 55 to 45 mph (88 to
             72 km/h)

     3.7.1.5 Bell Drive Dynamometers—The procedure outlined above has been
applied extensively to belt drive dynamometers. The next step is to plot the
indicated road  load horsepower at 50 mph (80 km/h) versus the actual road
horsepower at 50 mph (80 km/h). Fig.  5.
  The Federal Register advises running coastdowns at the inertia weight most
frequently  used. Common practice  is to run coastdowns at either all inertia
weight settings of a dynamometer or at least all inertia weights that are used
for  testing.
     3.7.1.6 Direct-Drive Dynamometers—The  same procedure can be used for
direct-drive dynamometers as for belt drive dynamometers and should be used
for  manual loading calibration of these units. However, automatic loading

-------
                                                                                                                                        25.111
                                       15
                                       10
                               t-O
                               QOC
                                  0
                                                                                           O
                                                                                 O
                                                                      O
                                                          O
                                                                            10
                     15
20
                                                     ABSORBED HORSEPOWER  AT 50 MPH
                                             FIG. 5—DYNAMOMETER  CALIBRATION CURVE
features of (he new direct-drive dynamometers can improve the coastdown
procedure. An outline of a direct-drive dynamometer  procedure is given in
Appendix C.
  The direct-drive dynamometer procedure sets  up the dynamometer for
operation at the desired operating points rather than finding a linear range for
each inertia weight. This procedure is rapid and reproducible in both running
coastdowns and  in operation: It  is recommended that  a  plot of frictional
horsepower versus inertia  weight  be made  for each set  of coastdown data.
These plots can aid in  determination that the coastdown data is valid.
  In Fig. 6, the frictional power is plotted as a function of inertia weight for
nine automatic loading direct-drive dynamometers. The data show that the
frictional powers are confined to an approximate 1 hp (745 VV) band. On these
plots, the "over 5500" values  are plotted  at 6000 for convenience.
  An example of the effect of recalibration is shown in the frictional power
versus inertia weight plot in Fig. 7.  A dynamometer recalibration indicated a
shift of over 0.5 hp (0.3 kW)  friction.  A  recalibration  showed that a speed
calibration error had been made. After correction,  a typical shift of less than
0.5 hp (0.3 kW) was observed.
  3.7.2  DYNAMOMETER  PROCEDURE
     3.7.2.1 The vehicle shall  be tested from a cold start. Engine startup and
operation over the driving schedule make  a complete test run. Exhaust emis-
sions are diluted  with  air to  a constant  volume  and  a portion is sampled
continuously during each  of the three test  phases. The composite samples.
collected in  three bags, are  analyzed  for HC. CO. NO,, and CO... Three
parallel samples of dilution air are similarly analyzed. CO., is measured
because it is needed in determining the carbon balance fuel economy.
    3.7.2.2 A Hxed-speed cooling fan with a nominal capacity of 5300 ft '/min
(150 nv'/min) is positioned during dynamometer  operation so as to direct
cooling air to the vehicle in an appropriate manner with the engine compart-
ment cover open. In the case of vehicles with front engine compartments, the
fan is squarely positioned between 8 and 12 in (200 and 300 mm) in front of
the cooling air inlets (grill). In the case of vehicles with rear engine compart-
ments (or if special designs make the above impractical), the cooling fan or
fans should  be  placed  such  that engine/vehicle temperatures normally en-
countered during road operation are approximated. The vehicle should be
nearly  level  when tested in order to prevent abnormal fuel distribution.
    3.7.2.3  Flywheels,  electrical,  or  other means  of simulating inertia as
shown  in Table 2 should  be used. If the equivalent inertia spccilicd is not
available on the dynamometer being used, the next higher equivalent inertia
available, not exceeding 250 Ib (113kg),  should be used.
    3.7.2.4  t'uwtr Ahsor/ition (mil Adjustment
  (a) The power absorption unit is adjusted  to reproduce absorbed horse-
power  at 50 mph (80km/h) road load. The  relationship between absorbed
power  and indicated power  for a particular dynamometer  .should be deter-
mined  by the procedure previously outlined.
  (b) The absorbed power listed in Table 2 is used or the vehicle manufac-
                                   8
                                   g
                                   ° *-•
                                   ISO 00
                                                           300.00    350.00    400 00    JSO 00    SOO 00
                                                                  INERTIA WEIGHT  10
                                               FIG. 6—TYPICAL FRICTIONAL HORSEPOWERS

-------
25.112
                                            a CALIBRATION OF DYNAMOMETER
                                            O RECAUBRATION OF DYNAMOMETER A ONE MONTH LATER SHOWING APPARENT SHIFT
                                            • IMMEDIATE RECAL AFTER FINDING AND CORRECTING A SPEED CALIBRATION ERROR
                                                                             «-

                                                                            -f:
                                                             30O.OO    3SO.OO    40000
                                                                  INERTIA WEIGHT  10
                                                                                             -..__.   I ._
                                                                                             50000     55000
                                                     FIG. 7—EFFECT OF RECAUBRATION
turer may determine (he absorbed  power by  the  following procedure and
request its use:
     (i) Measure the absolute manifold vacuum of a representative vehicle of
the same equivalent  inertia weight,  when operated on a level road  under
balanced wind conditions at a true speed of 50 mph (80 km/h).
    (ii)  Note the  dynamometer indicated power setting  required to  repro-
duce the manifold vacuum, when  the same vehicle is operated on the dyna-
mometer at a true speed of 50 mph (80 km/h).  The tests on the road and on
the dynamometer  should be performed with the same vehicle ambient abso-
lute pressure (usually barometric), that is, within ±5 mm of Hg.
    (iii) The absorbed power values are listed in Table 2.
     3.7.2.5 The vehicle speed must  be measured by a tachometer generator
installed on the rear (or idler) roll. A tachometer generator installed on the
front (or drive) roll is used to measure coastdown speed.  Even though most
tests conducted integrating front and rear tachometer generator speeds over
the test cycle have shown only small differences in total distance, the rear (or
idler) roll must be used  to measure  vehicle speed because of tire distortions
that occur on accelerations which change the rolling radius.
     3.7.2.6 The Federal Register recommends that minimum throttle  action
should be used to maintain the proper speed-time relationship. When using a
two-roll dynamometer, a truer speed-time trace may be obtained by minimiz-
ing the rocking of  the vehicle in the rolls. The rocking of the vehicle changes
the tire  rolling radius on each roll.  The  rocking may  be minimized  by re-
straining the vehicle horizontally (or  nearly so) by  using a cable and winch.
Care must be used to prevent tightening this cable too much as this could
cause vehicle  to be pulled off rolls.


        TABLE 2—EQUIVALENT INERTIA WEIGHT AND  ABSORBED POWER

loaded Vehicle Weight


Ib

Up to II 25
1126 lo 1375
1376 to 1625
1626 to 1875
1876 to 2125
2126 to 2375
2376 to 2625
2626 to 2875
2876 to 3250
3251 to 3750
3751 to 4250
4251 to 4750
4751 to 5250
5251 to 5750
575 1 or more

kB

Up to 511
512 to 624
625 to 738
739 to 851
852 to 975
976 to 1085
1 086 lo 1 1 95
II 96 to 1 306
1307 to 1475
1476 to 1700
1701 to 1930
1931 to 2150
2151 to 2380
2381 to 2610
26 1 1 or more

Equivalent
Inertia Weight


Ib

1000
1250
1500
1750
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
5500

kg

454
568
681
895
908
1022
1135
1250
1362
1590
1816
2045
2270
2500
2500
Abtorbed Power at 50 mph
(80 km/h) Without and
With Air Conditioning
load Simulation
Without


hp
5.9
6.5
7.1
7.7
8.3
8.8
9.4
9.9
10.3
11.2
12.0
12.7
13.4
13.9
14.4

kw
4.4
4.8
5.3
5.7
6.2
6.6
7.0
7.4
7.7
8.4
8.9
9.5
10.0
10.4
10.7
With


hp
6.5
7.2
7.8
8.5
9.1
9.7
10.3
10.9
11.3
12.3
13.2
14.0
14.7
15.3
15.8

kw
4.8
5.4
5.8
6.3
6.8
7.2
7.7
8.1
8.4
9.2
9.8
10.4
11.0
11.4
11.8
    :i.7.2.7 Drive wheel tires must be inflated to a cold gage pressure of 40 psi
(280 kPa). This  recommended practice  acknowledges that all  is not fully
understood regarding the rolls-tire interaction.  Recent tests using vehicles
having engines of 100-450 in:1( 1.6-7.4 x 10":1 nr') displacement show that the
average drive wheel  tire pressure  increased  from gage  pressure of 40 psi
(280 kPa) to 47 ± 3 psi (320 ± 21 kPa) after running the 1975 Federal Test
Procedure. When  the 75 FTP was immediately followed by  a Highway
Driving Cycle, the average gage pressure at the end of the test was 50 ± 3 psi
(340i20kPa).  These  observed tire pressure increases are approximately
twice those observed when vehicles are run on the road, confirming that  the
lire deflections on rolls probably generate more heat and thereby increase the
tire pressure. Further study is needed in this area. The cold gage pressure
recommended above is an initial step to minimize tire variations.
    3.7.2.8  Warmup oj Dynamometer—If the dynamometer has not been oper-
ated during  the 2h  period  immediately  preceding (he  test,  it should  be
warmed up for 15 min by operating it at 30 mph (48 km/h) using a nontcst
vehicle.
  •f. Calibrating and Operating Procedure
    4.1 Calibration Procedure—The purpose of this procedure is to provide
a reliable method  for calibrating CVS systems.
  A detailed discussion of the major requirements lor conducting an accurate
CVS  calibration  follows. The individual  sections are arranged in  proper
sequential order and provide detailed instructions for conducting the neces-
sary checks that must be performed for satisfactory results.
  4.1.1  PREPARATION OF  CVS SYSTEM FOR CALIBRATION
    4.1.1.1 Installation of Sampling Taps and Lines—For  measurement of the
pressure differential across the CVS pump, install static pressure taps of (he
type shown  in Fig. 8 at  the top and  bottom  of the CVS pump drive head
plate, centering on the inlet and outlet pump cavities.  The same static pres-
sure taps used for CVS calibration should be used for vehicle emission testing.
The location should provide at least  one diameter of straight pipe up and
downstream from the tap to minimize flow disturbances.  If a straight length of
pipe is not available, a piezometer ring from which a single gage connection is
led may be used.
    4.1.1.2 If the  straight section of pipe is  vertical, the static tap can  be
installed anywhere around the periphery.  If the pipe  is horizontal, the  tap
should be located  in the periphery of the upper half (above the pipe center-
line). The pump inlet  pressure tap should be located downstream from the gas
sample probes.
  The diameter and hole edge rounding of the pressure tap should conform
with the recommendations shown in Table 3.
  NOTE: It is realized  that it will seldom be practical and, generally, it will be
impossible actually to measure the radius of the hole-edge rounding. However,
if any dulling or rounding is  done, the  values in Table 3 offer a guide for
estimating the maximum desirable degree of edge rounding.3
  All burrs and  irregularities should be removed from the inner wall surface
near the static tap.

  •' "Static Pressure Cups and Fluid Meters—Theory and Application, " Fifth Chapter, Section
A!i. pp. 18-19. American Society of Mechanical Engineers. 345 East  47lh Street, New
York, New York 10017.

-------
                                                                                                                                           25.113
           STATIC PRESSURE TAP
                                           SAMPLE PROBE
                                                                          LFE INLET DEPRESSION
                                                                          ACCURACY  0 1 
-1 •



r:


/




SIDE
VIEW

_*»

^



~



^



FRONT
VIEW

^— '• 00 S S.


FIG. 8—srATIC  PRESSURE  TAP FITTINGS AND PROBE DESIGN
    4.1.1.3 The sample probes should be made of stainless steel and be of the
design shown in Fig. 7. They should be faced upstream directly into the flow.
All sample lines leading from the probes should be routed upward. This will
allow any water which  may condense  to drain out  of the lines and  thereby
prevent hydraulic  blockage. (Similar precautions should be taken when in-
stalling static pressure lines.)
  4.1.2  FLANGE GASKETS—When installing the plumbing on the inlet side of
the pump, compression  of the gasket  may cause  a decrease in  its inside
diameter. If this occurs,  it will affect  the restriction on the pump and may
affect the accuracy of the static pressure reading if the gasket protrusion is
upstream of the static tap. Therefore, when assembling the plumbing insure
that the  gasket ID as installed is  not smaller than the pipe ID.
  The placement of modal analysis probes relative  to the bag sample probe
can also disrupt sampling. It has been shown that the backflushing of a modal
analysis cart through  a probe can significantly affect the bag sampling probe
sample during  a CVS calibration verification  with propane injection.
  4.1,3  PRIMARY CVS CALIBRATION WITH LAMINAR FLOW ELKMKNT
    4.1.3.1 This procedure  utilizes a laminar flow element and a variable
restriction device to  generate a pump performance  curve (flow  rate as a
function  of pressure differential). Fig. (J is a schematic of the test layout and
instruments required to perform  this calibration.  The  volumetric  flow  is
determined by  a laminar flow clement (LFE) placed upstream of the CVS
pump (as shown in Fig. 9) to avoid introducing flow disturbances in the LFE.
A straightener section of 10 times the exit diameter  is added to the outlet  of
the LFE. This  is followed by an adjustable restriction valve. Since the LFE
and the pump are in series, it is necessary that all connections  between these
two items be free of leakage. It is advisable to plug all openings and pressure
test the system  to insure that the system is  free of leaks.
  Some LFE have straightener sections built into the device. This obviates the
use of a straightener section. However, these LFEs are subject  to calibration
shifts if they are disassembled for cleaning. If these units are  cleaned, they
should be recalibrated.
  When  conducting  calibration,  the  restriction device  should  be used  to
generate  data  points above  and  below the normal  CVS system operating
pressure. Data should be obtained  beginning with the piimp inlet depression
                      TABLE 3—PRESSURE TAP HOLES
Nominal Inside Pip*
Dia
in
Under 2
2 to 3
4 la 8
10 +
cm
Under 5
5 to 7.5
10 to 20
25 +
Pr«tsur« Holt
Dia
in
1/4 i 1/8
3/8 ± 1/8
1/2 - 1/8
+ 1/4
3/4 ±: 1/4
mm
6.4 ± 3.2
9.5 i 3.2
12.7 - 3.2
+ 6.4
19.0 ± 6.4
HoU-Edg* Rounding
Radius
in
About 1/64
Leu 1/32
Lest 1/32
Lest 1/16
mm
About 0.4
Leil 0.8
Less 0.8
Lew 1.6
                         DELIA P LF€
                            LINED OR MICROMANOMETER
                          .CCURACY  0005 IN H..O
                           NGE 08 IN H,0
                                                                                                                           VARIABLE RESTRICTION DEVICE
                                                                          LFE INLET TEMPERATURE
                                                                          ACCURACY  05F
                                                                          RANGE  60 -100 F
                                                                                  PUMP INLET DEPRESSION
                                                                                  ACCURACY  0 I IN H,0
                                                                                  RANGE 0 fiO IN M,0
                                                            PUMP INLET TEMP
                                                            ACCURACY  05F
                                                            RANGE 60 '170 F
                                                                                                 DELTA P PUMP
                                                                                                 ACCURACY  01 IN M..Q
                                                                                                 RANGE 0-90 IN H,0
                                                                           KIG. !)-(.:VS  CALIBRATION  WITH LAMINAR FLOW  ELEMENT -
                                                                                                       SCHEMATIC
corresponding to LFE as ihe only restriction. Pump inlet depression should be
increased by increments of 2-5 in H.jO (500-1250 Pa) until 6-8 data points
are determined.  Usually, it is difficult  to get points below the  normal CVS
system operating pressure  unless the heal exchanger is removed from the
system.  Most calibrations are done with the heat exchanger in the system.
  The following  listing of the  data to be recorded,  unit conversions, and
calculations will be followed  by a sample calculation and a computer print-
out.
    4.1.3.2  Data Recorded
  (a)  LFE inlet depression, in H..O  (Pa).
  (b)  Delta P LFE, in H2O  (Pa)"
  (c)  LFE inlet temperature, °F (°C).
  (d)  Pump inlet depression, in H.jO (Pa).
  (e)  Pump inlet temperature, °F (°C).
  (f)  Delta P pump, in H2O (Pa).
  (g)  Barometric pressure, in Hg (Pa).
  (h)  Pump rpm.
    4.1.3.3  Conversion of Units
  (a)  Convert in H._,O to in  Hg pressure:
       LFE inlet depression (in Hg) =  LFE inlet depression (in H..O)
                                      X 0.07355 in Hg/in H._.(.)
      Pump inlet depression (in Hg) =  Pump inlet depression (in Hg)
                                      X 0.07355 in Hg/in H,O
  (b)  Convert from degrees Fahrenheit to  degrees Rankinc:
      LFE inlet temperature  (R) = LFE inlet temperature (°F) + 460
    Pump inlet temperature  (R) = pump inlet temperature  ("F) + 460
  (c)  Conversion to absolute pressure:
 Absolute pressure (in Hg) at LFE inlet = barometric pressure (in  Hg)
                                          - LFE inlet depression (in Hg)
Absolute pressure (in Hg) at pump inlet = barometric pressure (in  Hg)
                                        — pump inlet depression (in Hg)
    4.1.3.4  Calculations
  (a)  Determine air viscosity correction factor for LFE inlet air temperature
from  LFE correction curve obtained from LFE manufacturer.
  (b)  Determine pressure correction factor for LFE inlet pressure from  LFE
correction table obtained  from  LFE  manufacturer.
  (c)  Determine uncorrected volume flow rate from curve supplied  by  LFE
manufacturer and pressure drop. Then determine corrected volume  flow rate
by  multiplying uncorrected volume  flow rate X air viscosity correction fac-
tor X pressure correction factor.
  (d)  Using Ideal Gas Law,  convert the volume flow rate at LFE standard
conditions (530 R, 29.92 in Hg) to the  volume flow rate  at the pump  inlet
temperature and pressure:                               pump in,e,
                                       29.92         temperature (R)
  Pump ftVmin = LFE ftVmin X  	 X	—
                                   pump abs inlet           530
                                  pressure (in Hg)
  (e)  Determine pump ft3/rev  by dividing ft3/min by the pump rpm.
  (f)  Plot pump ft3/rev versus the square  root of pump delta P. Determine
the first degree equation of the line by  the least squares method.
    4.1.3.5  Example of Calculations for LFE CVS calibration, using typical data
from a 400 ftVmin LFE.

-------
25.114
 Data Recorded
   (a) LFE inlet depression = 1.00 in H2O.
   (b) Delta P of LFE = 6.520 in H2O.
   (c) LFE inlet temperature = 75.5°F.
   (d) Pump inlet depression =  37.8 in H2O.
   (e) Pump inlet temperature = 78.0° F.
   (f ) Delta P pump = 60.0 in H2O.
   (g) Barometric  pressure = 29.34 in Hg.
   (h) Pump rpm  = 1421.
 Conversion  of Units:
   (a) LFE inlet depression = 0.07355 in Hg.
   (b) Pump inlet depression =  2.78 in  Hg.
   (c) LFE inlet temperature = 535.5 R.
   (d) Pump inlet temperature = 538 R.
   (e) LFE inlet,  absolute pressure = 29.27 in Hg.
   (f) Pump inlet, absolute pressure =  26.56 in  Hg.
 Calculations:
   (a) Air viscosity correction factor at 75.5°F (from  LFE manufacturer's
 curve) =  1.006.
                                                                                                                              DILUTION AIR FILTER
(b) Pressure correction factor =
                                        = 0.9783.
   (c) Uncorrected flow  rate  (from  LFE manufacturer's  curve) = 342.8
 ff'/min.
  Id) Corrected volume How rate = 342.8 x  I .006 x 0.9783 = 337.4.
   (e) Pump ff'/min = 337.4 x ^--^- X -^— = 3858.
                               26.56    530
(f)  Pump IV'/rev =

                            _ 0.2715.
   4.1.4 GAS STRATIFICATION CHECK
     4.1.4.1  With the CVS operating in its testing configuration, introduce a
 tracer gas, such as  100'^ propane, into the vehicle exhaust inlet of the CVS
 system as shown in  Fig. 10. The tracer gas should be introduced at a rate that
 will give a bag sample which produces at least a % full-scale deflection on the
 HC range normally  used  for reading bags. The use of a continuous HC
 analyzer on the dilute continuous sampling probe makes this rate determina-
 tion simple. The continuous analyzer is needed for the profile  determination
 of paragraph 4.1.4.2.
     4.1.4.2  Starting with the sample probe inlet opening at one side of the
 dilute streo-n,  run  a cross-sectional profile of the pipe, sampling at 0.5 in
 (13 mm) intervals (wall to wall). Record the concentration at each sampling
 point location. Conduct a second cross-sectional profile at 90 deg to the first
 profile. If concentrations from wall to  wall vary more than 1%, there is
 incomplete mixing.
  4.1.5 INDEPENDENT CVS SYSTEM VERIFICATION
     4.1.5.1  Introduction — The system verification technique involves the intro-
 duction of a measured quantity of a tracer such  as propane (or CO) at  the
 tailpipe sampling location. If all components of the system are functioning
 properly, the quantity of tracer calculated from that collected in the sample
 bag should agree closely with the quantity which was injected.  A measured
 amount of tracer gas partially diluted with air from a small auxiliary blower
 (Fig.  1 1) is then mixed with dilution air in the main stream of the CVS. To
 avoid possible leakage, the tracer gas should be introduced downstream of the
 auxiliary blower. The auxiliary blower is needed to aid mixing of the 0.02 ft3
                                   PUMP MOTOR
                                                  EIHAUST TO ATMOSPHCP.E
                                                                                        MEASURED
                                                                                        AMOUNT OF
                                                                                        PROPANE
                                                                                   AUXILIARY
                                                                                    BLOWER
TAILPIPE
CONNECTION
                                                                                          FIG. II—CVS  SYSTEM VERIFICATION
                                                                        (0.56 L) of propane that is used in a test. When propane is used as the tracer
                                                                        gas, it may be necessary to remove the charcoal filter from  the CVS. This will
                                                                        equalize the HC background in the two dilution air streams.
                                                                            4.1.5.2 Equipment
                                                                          (a)  CVS system to be checked.
                                                                          (b)  A container of instrument  grade  tracer gas.
                                                                          (c)  Analytical balance with a capacity to weigh the charged gas container
                                                                        and flow  regulator with a  resolution of 0.01 g.
                                                                          Instead of the weighing technique. How measurement  techniques  can  be
                                                                        used to determine the  amount of tracer gas  injected  into the CVS. These
                                                                        include: wet test meter, rotometer, and critical flow orifice.
                                                                          (d)  A tracer gas flow  regulator  which  is capable of adjustment to yield bag
                                                                        concentrations which are normally encountered during testing.
                                                                          (e)  An auxiliary blower of 10-30 fWmin (0.005-0.014 m:l/s) capacity.
                                                                          (f)  Analyzers to measure tracer gas.
                                                                            4.1.5.3 Proctdure
                                                                          (a)  Turn on CVS and allow stream pressure and temperature to stabilize.
                                                                          (b)  Weigh gas  container with  the flow regulator connected and  record
                                                                        weight.
                                                                          (c)  Purge the gas sample bags with dilution air.
                                                                          (d)  Simultaneously, activate CVS mixture  and dilution air bag sampling
                                                                        and the positive displacement  pump revolution  counter.
                                                                          (e)  After 30 s,  begin injecting tracer gas  into the CVS.  Set tracer gas flow
                                                                        rate to yield sample stream concentrations  approximating those encountered
                                                                        during vehicle testing.
                                                                          (f)  Record CVS data during tracer gas  injection:
                                                                            Average pump inlet temperature, °F (°C).
                                                                            Average pump inlet pressure, in H2O (Pa).
                                                                            Average pump differential pressure, in H2O (Pa).
                                                                          (g)  After 14 min 30 s total elapsed time, stop the tracer gas injection.
                                                                          (h)  After 15 min total elapsed time, stop  the CVS mixture and dilution air
                                                                        bag samples and the  pump revolution counter simultaneously. Record  total
                                                                        CVS pump revolutions.
                                                                          (i)  Analyze gases in the CVS mixture and dilution air sample bags. Record
                                                                        concentrations.
                                                                          (j)  Weigh tracer gas  container and record weight.
                                                                          (k)  Determine the  injected  weight of tracer gas by subtracting  weight
                                                                        measured in step 4.1.5.3(j) from weight measured in step  4.1.5.3(b). Record
                                                                        difference.
                                                                            4.1.5.4  Calculations
                                                                          (a)  Determine the mass of injected tracer gas indicated  by the CVS using
                                                                        the following formula:

                                                                                       Calculated mass = fmll X density X cone
                                                                          where:
                                                                                         = ff,  X
                                                                                                    "x-^f
                                                                                                         'p
                                                                                              528 R
           FIG. 10—EXHAUST GAS SAMPLING SYSTEM
                                                                                            29.92 in Hg

-------
                                                                                                                                           25.115
            K0 = volume of gas pumped by the positive displacement pump,
                 ft3/rev at ambient conditions. This volume is dependent on
                 (he pressure differential  across the  positive displacement
                 pump
            A' = number of revolutions of the positive displacement  pump
                 during the test while samples are being collected
            Pp = absolute pressure of the dilute exhaust entering the positive
                 displacement pump, that is, barometric pressure minus the
                 pressure depression below atmospheric of the mixture en-
                 tering  the positive displacement pump
            Tf — average temperature of  dilute exhaust entering positive
                 displacement pump during test while samples are being
                 collected,  R
       Density = density of tracer gas, g/ft3 at  68°F  and 29.92 in Hg pres-
                 sure.
                 Example:  Propane = 51.91 g/ft3
                           CO = 32.97 g/ft3
         Cone = concentration of gas in sample bag minus concentration of
                 gas in  background bag.

  (b) Compare the measured tracer gas weight to the calculated tracer  gas
weight and determine the percent difference, based upon the measured weight.
  (c) If the difference is greater than  :t2% investigate possible sources of
error and  repeat the verification.
     4.1.5.5 Critical  Flow Orifice—A simpler  alternative  to  the  gravimetric
procedure described above for CVS system  verification is  the use of a critical
flow orifice (CFO). The advantage of a calibrated CFO is that the weighing
steps are replaced by a single determination of a high  pressure level reading.
Appendix  D is an example of a data and calculation sheet for use with a CFO.
The CVS measurement is compared to the CFO measurement using the CFO
measurement as the standard. Again, if the percent difference is greater than
±2%, investigate possible sources of error and repeat  the verification.
     4,2 Operating  Procedure—A wide variety of CVS configurations  are
currently available.  The detailed operating procedure  for each configuration
will be unique, and  will depend upon the nature of the test being performed.
Requirements for hot and cold, weighting and  inclusion of multiple back-
ground  bags all necessitate  changes in the detailed  operating  procedure.
Furthermore, the required degree  of operator attention to the CVS console
during performance of an emission test varies from installation to installation.
Fully automated systems require almost no attention to detail. Once the test is
initiated, all functions including the diverting of exhaust  gas into the  appro-
priate sample bags at  the correct times and  even  changing of the paper filters
are all accomplished automatically. Other units  may require the operator to
perform each of these operations manually. As a result of these many  factors
(configuration of equipment, interfacing equipment for automatic control,
and test procedure),  no  attempt will  be made here  to  provide a detailed
step-by-step procedure. Any such procedure would be specific for a particular
unit and test objective, rather than of universal value. Each  operator should,
of course,  follow the  instructions of the CVS manufacturer and/or  system
designer as well as the test procedure outlined in the appropriate governmen-
tal  regulations. The remainder of this section will be devoted to items which
may be best described as "good operating practice" and are  more universally
applicable.
  First, it should be pointed out that the  concept of CVS  sampling is still
evolving. Areas of uncertainty still exist. Such an area is that of defining  the
acceptable "tailpipe depression" at  idle or positive pressure during  modes
such as acceleration and cruise, which the  CVS may exert upon the vehicle
during the performance  of an emissions test. The objective of the  operator
should be to employ  his given CVS unit in  a way which will  minimize its
effect upon vehicle operation.  Actual  CVS  design has  a large impact on
tailpipe depression or pressurization. Above and beyond this  the operator can
minimize  effects by insuring that  connections between the vehicle and  the
CVS are relatively short (5-6 ft (1.5-1.8 m)), of large  enough diameter (4 in
(100mm)  or larger) and that the inside wall of this  flexible connection is
relatively smooth (interlock  type tubing).
  A second area which deserves  attention is  that of preventing  moisture
condensation in the CVS or sampling lines. Condensation may remove soluble
gas species from the sample stream and interfere with the accuracy of NO,
measurements. The dew point of concentrated exhaust gas  is typically 120-
130°F (49-54°C). Therefore,  it is essential  that the exhaust  temperature  not
approach  this range before dilution  in the CVS mainstream. The use of a
short (5-6 ft (1.5-1.8m)) connection between the vehicle tailpipe and  the
CVS inlet will  help prevent  condensation in the connecting line. If the CVS
configuration is such that the exhaust  gas is cooled  prior to mixing with  the
dilution air, it  will  be necessary to insure that  condensation does not occur
before dilution. Dilution of the exhaust gas should  be sufficient to  preclude
condensation of moisture in the  main  flow stream.
  Condensation of  the dilute exhaust sample  may occur  in sample lines.
pumps, filters, and meters,  particularly  when  the  relative humidity of the
dilution air exceeds 50%. Unless  bubbles appear  in  the How  meters,  this
condensation may be difficult to detect. Dampness in the paper  filters in the
sample streams is an indication that condensation is occurring.  If condensa-
tion is a problem,  it may be necessary  to  install drain lines to divert  the
condensation back  into the main flow  path of  the  CVS upstream of the
positive displacement pump. Better approaches  to avoid the condensation
problem are to match the sample pump capacity more closely to the sampling
system and to use back-pressure regulated sample  pumps to reduce the maxi-
mum pressure to which the sample is exposed and thus reduce the tendency
for condensation to occur. Usually, humidity is  added to the test area so that
the relative humidity is  maintained near 50%, so  that the NO,  correction
factor  will  be near  unity.
   Deposits will slowly build up in the CVS. These are most likely to occur in
the heat exchanger. Good operating  practice  dictates regularly  scheduled
cleaning. Increase of depression at  the  pump  inlet  is a  good  indicator of
deposit buildup. Even though the CVS flow conditions are corrected for the
changing operating conditions, the deposit buildup is not uniform and conse-
quently can cause stratification at the sample probe.  Deposit buildup will be a
function of the number and type of tests. For a very active testing program.
monthly cleaning would be recommended.
   CVS pumps have been  known to seize. Usually, this is due to deposits and
moisture that remain  in  a CVS  after a scries  of intermittent tests. This
problem can be avoided by connecting  the CVS  outlet to a laboratory exhaust
system that has sufficient capacity  to rotate (he  blower slowly when the CVS
is  off. The  laboratory exhaust is effective in removing the moisture.
   Foreign objects can enter the CVS inlet and effectively destroy mixing or
cause severe  stratification. Large mesh screens  have been used effectively to
prevent foreign objects from reaching the  mixing area and the heat exchanger.
   The dilution air filter is not intended to remove all  hydrocarbons from the
inlet air, but rather to stabilize their  level. Precautions should  be taken to
insure that the dilution air is not contaminated with excessive HC vapor from
spilled gasoline,  etc. The dilution air filter package  is  normally a set  of three
24 x 24 in (600 x 600 mm) filters. The first is a dust  filter, the second a char-
coal filter, and the third filter to remove charcoal  particles from  the dilution
air stream.  These filters can become loaded with dirt.  An acceptable  method
for determining  the useful life of these filters is  to monitor the pressure drop
across  the filter when the  CVS blower is operating at high speed. When  the
pressure drop across the three filters reaches 0.5 in  H._,O (125 Pa),  the filter set
should be changed. If desired the charcoal could  be reactivated  and reused.
   A detailed calibrating procedure appears in another section. It should be
noted that, while this procedure is intended to uncover mechanical and  flow
problems which may exist, it is not a cure-all. Actual operating conditions are
somewhat different  from calibrating conditions. For example, the temperature
and flow  rate entering the CVS  during calibration  is different than  the
temperature and flow rate of exhaust entering during vehicle emission testing.
The degree of stratification under actual test conditions could differ from that
observed during  calibration. Mixing  difficulties  at  other  than  calibrating
conditions  will  lead to a  situation where, even though a CVS checks out
during the  calibration, during actual operation the mass obtained by inte-
grating the continuous diluted exhaust stream concentration does not agree
with that collected  in the  bags. When a situation  like  this is observed, it will
be  necessary to  repeal the  stratification check outlined in the calibrating
procedure with exhaust gas supplied by  a vehicle operating at  50, 40,  and
30 mph (80.5, 64, and 48 km/h) steady-states. If mixing is not complete it may
be necessary to experiment with unique mixing devices to aid or replace those
supplied with the CVS unit. Considerations such  as  those outlined above
emphasize  the importance of paying careful attention to each step of CVS
operation even when the  unit is completely automated. Each  configuration
has its unique advantages and problems. Furthermore, changes in  a given unit
may occur  from  time to time, so that what is not  a  problem at one moment
may become one later.
   5. Data Analysis—Two  types of data analysis are  possible, bag and modal.
Bag analysis will yield emission values which are the  composite for a complete
test. This kind of analysis is simpler  to perform, and is satisfactory for deter-
mining whether a vehicle will pass a given lest. Therefore, bag analysis is used
for surveillance or compliance testing. For development of emission control
systems, modal analysis is necessary to determine the relationships between
emissions and driving mode.
     5.1 Bag Analysis—The HC, CO,  NO, (NO  +  NO,), and CO, concen-
trations are measured in the diluted exhaust and the background bags. De-
pending upon the specific cycle used, more than one exhaust and one back-
ground bag may be needed. For the 1975 Federal Test Procedure, separate
exhaust bags are  needed for the cold transient, cold stabilized, and  hot
transient phases of the driving cycle, thus allowing weighting factors to be
applied to the cold  and hot transient phases of the test. It is good practice to
use a separate background bag for each  sample bag used, in case the back-
ground concentrations change during a test.

-------
25.116
  5.1.1  EXHAUST EMISSION CALCULATIONS—One diluted exhaust sample bag
and one background bag are required for each test phase. The concentrations
of HC. CO. NOX.  and CO, in the bags are determined by passing the  gases
through the analyzers described  in paragraph 3.2.
    5.1.1.1 The final  reported test results are computed as follows:
                 J'irm = (x\Yi + x-yy  + -V3K3)/7.5 miles
where:       Yu.m  = weighted mass emissions of each pollutant, that is, HC,
                    CO.  and NO,, g/vehicle mile
       A',, A',,  A',  — 0.43, 1.0, 0.57. respective weighting factors for each test
                    phase
        ^i' ^'a- ^3  ~ mass emissions for each phase, g/phase
                I  = cold  transient test phase
                2  = cold  stabilized test phase
                3  = hot transient test phase
    5.1.1.2 The mass of each pollutant for  each phase of the test is deter-
mined from the following:
  (al  HC mass:
                                                Hf
                HCmas,  = Vml, X density,,,, X
   (b) CO mass:
                 c°m«. = v,ni. X density(:o X
                                                1 000000
                                               1 000000
   (c) NO, mass:
                 NO.
                         = V
                              „ X densilyNO  X
 -NQ...,,.,.
I 000000
                                             X Kh
  id) CO., mass
                              »« X dcnsi'yco, X
                                                CO.,
                                                  100
     5.1.1.3 Meaning of Symbols
     HCmls, = hydrocarbon emission, g/'test phase
   Dcnsity,,c = density of hydrocarbons  in  the  exhaust  gas, assuming an
                average  carbon-to-hydrogen  ratio of  1:1.85 g/ft3 at  68°F
                (20°C) and 29.92 in Hg (101 kPa) pressure (16.33 g/ft3)4
      HCronc = hydrocarbon concentration of the dilute exhaust sample cor-
                rected for background, ppm carbon equivalent, that is equiv-
                alent propane X 3
      HC,.,
= HC, - HCd(l  - I /OF)
        HC, = hydrocarbon concentration of the dilute exhaust sample as
                measured, ppm carbon equivalent
        HC,, = hydrocarbon concentration of the background as measured,
                ppm carbon equivalent
     C'.OmM, = carbon monoxide emissions, g/test phase
   Density,.,, = density of carbon monoxide g/ft:lat 68°F(20°C) and 29.92 in
                Hg (101 kPa) pressure (32.97 g/ft3)
      CO,.,,nr = carbon monoxide concentration of the dilute exhaust sample
                corrected for background,  water vapor,  and CO2  extrac-
                tion, ppm
      00ronc = CO, -C0d(l - I /DF)
        CO, = carbon monoxide concentration of the dilute exhaust sample
                corrected for water vapor  and carbon dioxide extraction,
                ppm. The calculation assumes the hydrogen-carbon  ratio of
                the fuel is 1.85:1
        CO, = (I - 0.01925 CO2  - 0.000323 R)CO,
       (CO, = CO,  , if instrument has no CO2 or H2O  response)
       CO,  = carbon monoxide concentration of the dilute exhaust sample
                as measured, ppm
       CO2 = carbon dioxide concentration of the dilute exhaust  sample,
                mol %
           R = relative  humidity of the dilution air, %
        CO,, = carbon monoxide concentration of the background  air cor-
                rected for water vapor extraction, ppm
        CO,, = (I - 0.000323 R)CO^
       (CO,, = COd , if instrument has no H.X) response)
       CO,,  = carbon monoxide concentration of the background air sample
                as measured, ppm
     NO,    = oxides of nitrogen emissions, g/test phase
   DensityNO = density of oxides of nitrogen  in  the exhaust gas,  assuming
                they are in the form of nitrogen dioxide, g/ft:1 at 68°F (20°C)
                and 29.92 in Hg (101 kPa)  pressure (54.16 g/ft:1)

  •Density of emissions are based on Ideal Gas Law. Density is equal to  1.17714 times the
molecular weight.
                                                                                 NO,

                                                                                 NO,
                                                                                    *((

                                                                               CO,
                                                                                   rriMt
                                                                            Densityco  =

                                                                               CO,    =
                                                                                   Tone

                                                                               CO,    =
                                                                                   "rone
                                                                                 CO2  =

                                                                                 CO,  =
                                                                                    "
                                                                                   DF =
                                                                            oxides of nitrogen concentration of the dilute exhaust sample
                                                                            corrected for background, ppm
                                                                            NO, - NO^d  - I/Of)
                                                                            oxides of nitrogen concentration of the dilute exhaust sample
                                                                            as measured, ppm
                                                                            oxides of nitrogen concentration of the background as meas-
                                                                            ured, ppm
                                                                            carbon dioxide emissions, g/test phase

                                                                           : density of carbon dioxide g/ft1 at 68°F (20°C) and 29.92 in
                                                                            Hg  (101 kPa) pressure (51.81 g/ft3)
                                                                           : carbon dioxide concentration of the dilute exhaust sample
                                                                            corrected for background, %
                                                                            CO2 -CO2j(l  - \/DF)
                                                                            carbon dioxide concentration of the dilute exhaust sample as
                                                                            measured, %
                                                                            carbon dioxide concentration of  the  background  as  meas-
                                                                            ured, %
                                                                                       13.4
       CO,  + (HC, + CO,) 10-4

Vmi%  = total  dilute exhaust  volume, ft'Vtest phase  corrected  to
       standard conditions (68°F,  29.92 in  Hg) (528 R,  101 kPa)
f/mi,  = K, X  /V x (/>p/29.92)(528/rj
  1'0  = volume of gas pumped by the positive displacement pump,
       ft3/rev. This volume is dependent upon the pressure differen-
       tial across the positive displacement pump
  .V  = number of revolutions of the positive displacement pump
       during the test phase while samples are being collected
  Pf  = absolute pressure of the dilute exhaust entering the positive
       displacement  pump,  in  Hg,  that  is, barometric pressure
       minus the pressure  depression below atmospheric  of the
       mixture entering the positive displacement pump
  Tf  = average temperature of dilute exhaust entering the positive
       displacement  pump  during test  while samples  are  being
       collected
  Pt  = barometric pressure,  in Hg
 T^  = wet bulb temperature, °F
  Tt  = dry bulb temperature, °F
 Pw  = saturation water vapor pressure, in Hg at wet bulb tempera-
       ture
 Pw  = -4.14438 10-3 +  5.76645 10-X  - 6.32788 10-57V  +
       2.12294 lO-6'^3 - 7.85415 IQ-"^4 + 6.55263 10-"TV1.
       This equation is a least squares fit of the  Keenan and Keyes
       "steam table". It reproduces steam table values  within
       ±0.001 in Hg for temperatures of 20-110°F.
  Pt  = saturation water vapor pressure in Hg at dry bulb tempera-
       ture. Same equation as for Pw except Td is used instead of Ta
  A  = experimentally derived constant for use in Ferrel's equation
       as recommended by  NBS
  A  = 3.67 10-4 (1 + 0.00064) (Ta - 32)
  Pv  = partial pressure of water vapor, in  Hg (found from Ferrel's
       equation)
       Pw  — A P,, (Td —  Tw), Ferrel's equation
       absolute humidity, grains H2O/lb dry air
       4347.8 P.,
                                                                       /".=
                                                                       H —

                                                                       H =
                                                                          = humidity correction factor
                                                                                     1
                                                                             I - 0.0047(// - 75)
                                                                        R =  relative humidity, %
                                                                             />
                                                                        R =  —- x 100
                                                                             P*

                                                                 5.1.1.4 Calculation of Mass Emission Values—Computers are generally used
                                                             to determine the mass emission values. To verify computer programs, Appen-
                                                             dix E detailing hand calculations can be used.
                                                                 5.2 Modal Analysis—Modal analysis is necessary for the development of
                                                             emission controls because it relates cause and effect. The cause is the particu-
                                                             lar engine system  at a specific operating point. The  effect is the resulting
                                                             emissions. Mode of operation can be defined its an idle, cruise, acceleration,
                                                             and deceleration. The length of a mode could be several minutes or as short as
                                                             1 s. At least two methods of modal analysis are available: continuous analysis
                                                             of diluted vehicle exhaust, and continuous analysis of undiluted exhaust using
                                                             the CO2 tracer technique.

-------
                                                                                                                                      25.117
  5/2.1 CONTINUOUS ANALYSIS USING DILUTED VEHICLE EXHAUST—Any driv-
ing schedule can be broken down into arbitrary modes such as idle, accelera-
tion, cruise, and deceleration.  For each mode, the mass emission of each
pollutant can be computed using the equations of paragraph 5.1.1.2 modified
slightly. The modifications are: The HC, CO,  and NO, masses will be in
grams per mode. Generally, a computer will be advantageous for performing
the large amount of calculation required for continuous modal analysis.
    5.2.1.1 Calculation of  Vm^for  One Mode—The  diluted exhaust  volume,
ft3/mode. can be calculated as in paragraph 5.1.1.3, except that N should be
taken as  the number of  pump revolutions for the individual mode being
calculated. The number of pump revolutions can be sensed with magnetic or
photocell pickups  and fed into the computer. For short modes, it may be
necessary to measure partial  pump revolutions  in order to obtain sufficient
accuracy.
    5.2.1.2 Calculation oj HC,.onc, COconc, am/NO,  —These quantities have
the same  meaning as in  paragraph 5.1.1.2, except that they now are the
average concentrations for each mode. The output of the HC, CO, NOX, and
CO., analyzers can be continuously monitored by a computer, with suitable
provisions for time delays  between the vehicle driver's mode changes and the
                                                corresponding analyzer output change. The computer can be programmed to
                                                lime average the concentrations for the specified intervals corresponding to
                                                the individual modes,  and make the required  corrections. However, it is
                                                difficult to measure the background HC. CO, NO,, and CO2 concentrations
                                                continuously in the dilution air unless separate analyzers are available, which
                                                is not usually the case. Therefore, some approximation may be necessary, such
                                                as measuring the background before and after the test and assuming a linear
                                                relation in between, or collecting an average background dilution air sample
                                                for the entire test.
                                                   5.2.2  MODAL ANALYSIS  USING CO., TRACER METHOD—There are many
                                                inherent difficulties in  continuously analyzing diluted  vehicle exhaust, pri-
                                                marily because of the very low diluted concentrations obtained for some
                                                modes. These problems can be avoided by continuously measuring the undi-
                                                luted exhaust concentrations of HC, CO, NO,, and CO2.  If the undiluted
                                                exhaust CO., concentration is  also measured continuously, it  is possible to
                                                calculate the vehicle exhaust volume for each mode. From the exhaust volume
                                                and the undiluted  exhaust concentrations, the modal mass of each pollutant
                                                can be calculated. Actually, any constituent of the exhaust can be used as the
                                                tracer, but CO., is a good choice  because it occurs in  the largest and most
                       "I < >(*  HC

                       I  '-0 38?
                       -i  i t  ».r
                       *  f.«  2";
                       :  10   *
                             CYILI
           '.*»ir»E  cone	
            tO    NO  C02    02  C02P
            A?-!   3i  1 82  16 ?   1?
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            (H^,  107 10 90   33   97
              i   (ORAHS/MILE>
                                                                HC
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      CYCLE  3   (GRAHS/HILE)

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-------
25.118
constant concentration and, therefore, is easiest to measure accurately even
after dilution.
    5.2.2.1 Exhaust Modal Mass Flow Calculations Using CO-, Tracer Method-
Assume that the modal average undiluted exhaust HC, CO, NO,, and CO2
concentrations are measured, and that the modal average CO2 concentrations
are measured  in the diluted exhaust stream. The diluted exhaust volume
ftVmode. Vmil, can be calculated as described in paragraph 5.2.1.1. Assuming
a constant for  background  CO2, the  average exhaust dilution ratio for each
mode can  be calculated as follows:
lculated as follows:
        CO2 exhaust — CO2 backgroun
     ~  CO2 CVS - CO2 background

        olume  ft3mode is:
                                                  nd
The undiluted exhaust volume, ft3/mode, is:
                           Vund = VmlI/DR

The modal mass is given by following:
             Hp         _ HCconcund  X Vund X densityHC
             I***-*modal maw ~             IQS           ~~

                            COconcund  X Vund x densityco
             CO
                                                                      NO.
                                                                                                I06
                modal mass ~~
                                        106
                    The upper portion of Fig.  12 shows only a hot transient modal mass output.
                    Several pages may be required for a complete test. The mass emissions for
                    individual modes can then be summed for the complete test, and these values
                    compared with the mass emissions computed from the bags. Theoretically, the
                    total of the modal masses  should be equal  to the mass emissions calculated
                    from the bag data. In practice, there will not usually  be perfect agreement,
                    but the bags should agree  with the modal total for each phase within a few
                    percent. Fig. 13  is an example of a computer mass summary. The weighted
                    mass values of Fig. 13 can be compared to the weighted modal data of Fig. 12.
                    Fig. 14 shows the results of the bag versus modal NO, comparison when the
                    chemiluminescent NO, analyzer was used.
                        5.3 Background—The exhaust dilution inherent in the operation of the
                    constant volume sampler  results in low concentrations of  pollutants being
                    presented to analyzers. Under some conditions, such as testing vehicles with
                    very low emission levels, the diluted exhaust concentrations are not far above
                    the background  level of pollutants  found in the dilution air. Therefore, it is
                    important that background levels  of pollutants be taken into account when
                    measuring vehicle emissions.
                        MO
                                            DAO  RESLJL-TS  »•»•»
                                             HC       CO      NOX      C02
C. T. ZERO IT
v. '1 SPAN !>ttC
C. T. SPAN CK
C. T MID «'fC
C. T. HID-*;" CK
• 1 
C. « ZERO t K
C. !i. SPAN SPEC
7. !i. SPAN (:•<
C. S. fllD SPCC
C. S. NID-W CK
•2 (C. s <;rw>>
tr, (C. 5. ftllH)
H '1 ZERO CK
H. T. SPAM SSKCC
H. 1. SPAN CK
HI. mo srer
M. T. MIO-« CK
»'•> (M T SftHP)
H, (H T. ANN)

92.
92.
36.
38.
32.
2.

91.
92
36.
38.
3
2.

92.
92
3*.
38.
7
3.
4
2
S
8
3
6
4
2
2
7
8
4
4
6
4
2
2
8
2
2
0
1.
1980
1378.
450
463.
1337
6.
1.
iseo.
1 370
43O.
466.
42.
3.
1
1380.
1384
130.
466.
36«
4.
3
0
6
O
4
3
7
O
O
9
0
e
3
0
2
0
4
0
2
8
3

80.
80
16
18.
73


80
eo.
16.
18.
43.


8O
80
16.
18
88.

0
0
1
1
0
7
3
0
0
3
|
2
4
3
0
O
3
1
0
8
3

3
3
2
2.
2


3
3
2
2.
1.


3
3
2.
2
2.

03
43
43
13
08
39
07
03
43
41
13
07
63
07
03
43
42
13
06
08
07
                        <»•«»••  O»A   MASS   TEST  RESUL.TS  »•»•»
                        COLD TRANS
                        COLD STAR
                              HC       CO     NOX
                             3. 62   1O3  9    10  29
                               22     51    10  38
                               33    29  9    12. OO
                       ORWS/MILI
                        COCO TNftNS
                        COLD STAB.
                        HOT   TRAN;>.
                        W-.IOHTCO  lOfAL
                              HC
                            I. ou/
                              037
                              132
  CO      NOX
29. 4i    2 8t-O
 1 31    2 662
 8 03  '  3. 334
 C02
 3U6
 33O9
 2506

 C02
879 4
648 6
696 7
                                             279
                                                     8 93
                                                             2 887    813. 4
 EC ON
 9 33
10 43
12. 30

10. 71
                       ECON
               COLU• f.  HOr-7'.
                  9 99    11. 34
                                                TOT-7?
                                                 10  4-9
                       • ••»•»  TK-.ST

                       TEJ;T DATE    7-27-7.*
                       DRV  BULB    //
                       VEH  NO  4O5
                       DILUTION FACTOR
                       Kf.LATIVC HUMIDITY  > PRESSU>tt: DIFF.  I
                       AV(> CVS FLOW (CO. FT/REV)
                       TOTAL CVS VOL  (STD <
                       AVO  MODAI.  C02 RATIO
TEST NO. 4H 26
UET BLCB 67
MODEL NO. 3D37
COLD TRANS
4. 9O2
60
I. 047
887O
) F) 103
i F) 88
(. F ) 96
)) 8 3
)) 7 1
)) 7 7
120) 14 0
(20) 12. 8
(20) 13. 4
299
•T ) 2411
4 33
6012 TEST
TIME 1887 4
BAROMETER 29. 21
CID
COLD STAD
8. 194
60
1 047
13070 .
104
9O
99
8. 1
7 7
7. 9
13 9
13. 3
13. 7
299
4O72
7 04
360
HOT TRANS.
6. 323
60
1 O47
8800
102
83
93
8. 3
7. 4
7. 9
14 4
13. 3
13. 8
299
2393
3. 20

ODOMETER 13278
TRANS A

















                                                    FIG.  13-EXAMPLE OF  BAG DATA

-------
                                                                                                                                          25.119
    2
    tr
    o
    o
    z
            300      425
                               5.50
                                        6.75
                                                  800
                               MODAL NOX. GRAMS MILE

             FIG.  14 —BAG NO.  VERSUS  MODAL NO
  Fig.  15 is a partial schematic diagram of a constant volume sampler. The
following equations apply:
                                     = v'
                                                                    (I)
where:  VK = volume of vehicle exhaust
        VD = volume of dilution air
       V'mjx = volume of diluted exhaust

                       VECE + V,)CD = viuixc:m,x                    (2)
where:  CF = concentration of a given pollutant  in the undiluted exhaust
        C,, = concentration of same  pollutant in the dilution  air (back-
              ground)
       ^''cnii = ttmccniration of the  same pollutant  in  the diluted exhaust
  Eq. 3 expresses the correct way of calculating the true mass emission of the
test vehicle, which is the quantity, V'pCp. However, the application of Kq. 3
requires that V'K be measured, which is not done in practice. An approxima-
tion  to the correct value of V'KCB  can be obtained by neglecting  the VKCD
term in the right-hand side of Eq.  3. The background concentration is merely
substracted  from the diluted exhaust concentration of the same  pollutant.
This method may be satisfactory if the background concentration and/or V'F
is small compared to V1I11X.  However, for  very low emitting vehicles whose
diluted exhaust concentrations approach the background concentrations, it is
necessary to apply Eq. 3 more rigorously, which requires the determination of
either vehicle exhaust or the dilution air flow. The procedure of  paragraph
                                                                          5.1.1 may be used, wherein the exhaust dilution factor is estimated by means
                                                                          of the empirical equation:
                                                                                                               13.4
                                                                                             DF =
                                                                                                                         10-
                          CO, + (HC_  + CO,
  Then VE is approximately equal to Vlnix divided by DF. With VE known,
Eq. 3 can be used. This technique avoids the need to measure either the
exhaust flow  or the dilution air How, and may be satisfactory for all but the
most rigorous testing. Eq. 3 is applicable to continuous modal analysis as well
as to bag samples.
    5.4 Fuel Economy Calculation from Exhaust Emissions—It is possible to
calculate fuel economy from a vehicle's exhaust  emissions using a form of
carbon balance. The carbon in the fuel can be calculated as follows:
Fuel density, g/gal = 8.331  X 0.7404 x 453.6 = 2798
             8.331 Ib/gal = density of water
                  0.7404 = specific gravity of typical gasoline
              453.6 g/lb = conversion factor

Weight  fraction  of carbon  in  fuel, assuming fuel of composition CH, sr, =
12.0 II,'(12.011 + (1.85 x  1.008)) = 0.866

                   12.011 = atomic weight of carbon
                    1.008 = atomic weight of hydrogen

Grams of carbon per gallon  of fuel =  (fuel  density. g/gal)(wt'/; C in fuel) =
2798 x 0.866 =  2423
The carbon  in the exhaust can be calculated as follows:
   Mass C in HC  = (HC g.'milcl(wt'>; C in HO molecule, assume OH, M)
                 = (HC g/mile)(0.866)
   Mass C in CO = (CO g/mile)(wtV{ C in CO molecule)
                 = (CO g/mile 1(12.011/12.011  + 16)
                 = (CO g/mile)(0.429)
  Mass C in CO2 = (CO2 g/mile)(wt% C in  CO, molecule)
                 = (CO2 g/mile)( 12.011)/(I2.0M + (2 x 16))
                 = (CO2 g/mile)(0.273)
Total mass of C in the exhaust,  g/mile  = 0.866 HC g/mile  + 0.429 CO
g/mile + 0.273 CO2 g/mile
The vehicle  fuel economy can be calculated as follows:

             miles/gal  = (g C/gal fuel)/(g/mile C in exhaust)

                                       2423
                        0.866 HC +  0.429 CO  + 0.273 CO,

                      	2798	
                         HC + 0.495 CO + 0.315 CO,

where HC, CO, and CO, represent the grams/mile of these respective exhaust
emissions for the vehicle.
  Different values for fuel density and/or fuel H/C ratio will yield a slightly
different equation.
  5.4.1  WEIGHTED FUEL ECONOMY—"Weighted" fuel economy is the carbon
balance fuel economy based on weighted emission  values found from the 1975
Federal Test  Procedure. This weighted fuel economy is identical to the fuel
economy that would  be obtained  if the fuel economies were calculated for
each of the three phases of the 75 FTP, and then weighted in the same manner
as the emissions. The proof follows: Subscript w refers to the 75 FTP weighted
emissions, subscript 1, 2, and 3, refer to the 75 FTP phase. The distance for
phase 1 and phase 3 is 3.59 miles, and the distance for  phase 2 is 3.91 miles.
The weighting factor for phase 1  is 0.43 and for phase 3 is 0.57.
                                                                                                           2423
                                                                                  HCU. =
                                                                                  CO,,. =
                                                                                  CO2  =
                0.866 HC^  + 0.429 CO^ + 0.273 CO^
                0.43(3.59) HC, 4- 3.91 HQ. + 0.57(3.59) HC,
                                     15
                0.43(3.59) CO, + 3.91 CO, + 0.57(3.59) CO..,
                                     _

                0.43(3.59) CO,,  + 3.91 CO,, +  0.57(3.59) CO,.,
                                      _
                                                                          Substituting Eqs. 2, 3, and 4 into Eq. I and rearranging terms gives:

                                                                                                             2423(7.5)
                                                                                 /••£„. =
      FIG.  15—CONSTANT VOLUME SAMPLER SCHEMATIC
              0.43(3.59)(0.866 HC, + 0.429 CO, 4- 0.273 CO.,,,) +
                (3.91)(0.866 HC, + 0.429 CO, + 0.273 CO,,) +
               0.57(3.59)(0.866  HC:, + 0.429 CO., + 0.273 CO,:1)
                                                                                                                                              (1)
(2)
                                                                                                                                              (4)
                                                                    (5)

-------
25.120
  The carbon balance formula applied to the emissions lor each test phase is
given by:
                     0.866 HC,  + 0.429 CO, + 0.273 CO.^

where: n indicates the test phase. Substituting Eq. 6 into Eq. 5 gives
                                      7.5
                         0.43
                              F
  The denominator is simply the gallons for each test phase weighted in the
same manner as emissions.
  5.4.2 FUEL ECONOMY CYCLE—The carbon balance fuel economy can be
determined  from any cycle, where emissions  have been  measured and are
expressed in grams/mile.  Recently EPA has developed a Highway  Driving
Cycle for fuel economy measurements. The driving sequence for this cycle is
                                                                          shown in Appendix F. This 12.75 min cycle has an average speed of 48.20 mph
                                                                          (77.6 km/h) and covers 10.24 miles (16.5km).
                                                                             ft Safety Recommendations
                                                                               6.1 Dynamometer—The test  vehicle should be restrained on the dyna-
                                                                          mometer by  using  tie-downs or other suitable  means. The maximum speed
                                                                          and acceleration/deceleration  rates of the dynamometer must  not be ex-
                                                                          ceeded.
                                                                               6.2 Calibration Gas Cylinders
                                                                             6.2.1 HANDLING—Gas cylinders  must not be moved unless the safety cap is
                                                                          securely screwed on the cylinder. Gas cylinders must always be supported by
                                                                          chains or other suitable means when in use, transported, or in storage.
                                                                             6.2.2 Toxic OR DANGEROUS GASES—Gases such as CO and NO, must be
                                                                          used in an area with  adequate ventilation. An ambient CO monitor for the
                                                                          emissions laboratory area is suggested.
                                                                               6.3 Vehicle Fuel (Gasoline)—Vehicle fuel must always be contained in
                                                                          safety containers.
                                                                  APPENDIX A
                                                   NO, CONVERTER EFFICIENCY CHECK
                                                                    (See Fig. 4)
1.  Attach NO/Nj supply to NO inlet on NO, generator at C2 (NO concentration approxi-    6. Turn off ozonator.
   mately 95% of full-tcale), O2 or air supply at Cl and efficiency checker to analyzer at C3.      Record actual reading .
2.  With ozonator of NO, generator off, oxygen or air supply off, and analyzer in bypass    7. Repeat steps 4 through 6 as necessary.
   mode, adjust NO 'N2 flow to analyzer. Zero analyzer and adjust span calibration to indicate
   approximately 100% of full-scale while flowing NO from NO, generator.               8. Calculate efficiency as follows:
   Record actual reading 	.	
                                                                                          % Efficiency  = — X 100V.
                                                                                                       6—4
                                                                                          % Efficiency =
3. Turn oxygen or air supply of NO, generator and adjust MVI to obtain analyzer reading of
  approximately 90% of full-scale.
  Record actual reading	
                                                                             Note: Converter efficiency must be greater than 90% and should be greater than 95%.
4. Turn on ozonator power and adjust varioc to obtain approximate 20V. full-scale reading.           Check efficiency weekly.
  Record actual reading	

5. Place  analyzer in converter mode.
  Record actual reading 	
                                                                                   Record Test Cell, Analyzer, Date and Operator
                                                                  APPENDIX B
                                                     STANDARD REFERENCE GASES FOR
                                                    AUTOMOTIVE  EMISSIONS ANALYSIS
  The NBS Office of Standard Reference Materials announces the availabil-
ity of Nitric Oxide in Nitrogen SRMs as  its fourth series of SRMs for mobile
source emission  analysis.  These SRMs  are  individually  certified, and  are
available at the  following nominal concentrations:
    SRM  1683—Nitric Oxide in Nitrogen. 50 ppm
    SRM  1684—Nitric Oxide in Nitrogen, 100 ppm
    SRM  1685—Nitric Oxide in Nitrogen, 250 ppm
    SRM  1686—Nitric Oxide in Nitrogen, 500 ppm
    SRM  1687—Nitric Oxide in Nitrogen, 1000 ppm
  The availability of the first two series. Propane in Air and Carbon Dioxide
in Nitrogen, were announced  in February 1973, and consist of the following
nominal concentrations:
    SRM  1665—Propane in Air. 2.8 ppm
    SRM  1666—Propane in Air, 9.5 ppm          $
    SRM  1667—Propane in Air, 48 ppm
    SRM  1668—Propane in Air, 95 ppm
    SRM  1669—Propane in Air. 475 ppm
    SRM  1673—Carbon  Dioxide in Nitrogen, 0.95%
    SRM  1674—Carbon  Dioxide in Nitrogen, 7.2%
    SRM  1675—Carbon  Dioxide in Nitrogen, 14.2%
  The availability of the third series. Carbon  Monoxide in Nitrogen, was
announced in January 1974, and consists of:
    SRM  1677—Carbon  Monoxide in Nitrogen, 9.74 ppm
    SRM  1678—Carbon  Monoxide in Nitrogen, 47.1 ppm
    SRM  1679—Carbon  Monoxide in Nitrogen, 94.7 ppm
    SRM  1680—Carbon  Monoxide in Nitrogen, 484 ppm
    SRM  1681—Carbon  Monoxide in Nitrogen, 957 ppm
                                                                             The development of these SRMs is a cooperative effort by National Bureau
                                                                          of Standards and the Environmental Protection Agency to provide standards
                                                                          that are needed to monitor compliance with automotive emission laws.
                                                                             These standard reference gases  are not to be considered as daily working
                                                                          standards, but rather as primary standards to be used in the calibration of daily
                                                                          working standards  obtained from  commercial sources, and by gas manufac-
                                                                          turers to help control the quality of the working standards during processing.
                                                                          Thus, they provide a traceability  of all gas  standards used  in mobile-source
                                                                          emission analysis back  to a central reference point, the National  Bureau of
                                                                          Standards.
                                                                             These gases are supplied  in cylinders with a delivered volume of 31 ft3 at
                                                                          STP. The cylinders conform to  the DOT 3AA-2015 specification.
                                                                             The certified concentration of gas in each cylinder is given on the certifi-
                                                                          cates issued at the time of purchase. For propane, carbon dioxide,  and nitric
                                                                          oxide, cylinder labels list only  the nominal  concentration and these SRMs
                                                                          should be used only in conjunction with the printed Certificate of Analysis.
                                                                          Because the  Certificate of Analysis may not accompany the cylinders, pur-
                                                                          chasers are requested to list the name of the actual user on the purchase order
                                                                          so that  the Certificate of Analysis can be mailed directly to the user.
                                                                             The cost of these SRMs includes the cost of the cylinder: for Propane in Air
                                                                          (SRMs 1665-1669) and Carbon Dioxide in Nitrogen (SRMs 1673-1675) the
                                                                          cost is $280  per cylinder; for Carbon Monoxide in Nitrogen (SRMs  1677-
                                                                          1681) the cost is 8303 per cylinder; and for Nitric Oxide in Nitrogen (SRMs
                                                                          1683-1687)  the cost  is  S303 per cylinder. Purchase orders for these SRMs
                                                                          should be sent to the Office of Standard Reference Materials, B311 Chemis-
                                                                          try,  National Bureau of Standards, Washington,  DC 20234.

-------
                                                                                                                                                            25.121
                                                                          APPENDIX c:
                                                       PROCEDURE  FOR AUTOMATIC LOADING
                                                              DIRECT-DRIVE  DYNAMOMETER


Procedure:
  1. Verify dynamometer speed and indicated horsepower calibrations.
  2. Use typical weight car to run coastdowns after verifying speed calculation
  3. Set inertia weight ta 1750, horsepower to 7.7 (indicated about 6 hp)
  4. Run coastdown recording lime between 55 mph and 45 mph
    (a)  Read horsepower directly with computer if available, or
    (b)  Determine coostdown time between 55 and 45;
  5. If necessary adjust internal pot. on auto. dyno. Repeat coastdowns until horsepower or time (depending upon your system)  is  within O.I hp or O.I.
  6. Repeat coastdown without further pot. adjustment.
  7. Record FINAL repeated HORSEPOWER or TIME value.
  8. Drive vehicle at 50 mph.  Record INDICATED HORSEPOWER as observed on meter.
  9. Repeat above for all inertia weights.
10. Check I or  1  coastdowns W AC set paint. Friction should be  the same at  each inertia weight.
1 1. Find friction horsepower at each inertia weight, plot and compare with  previous coastdown results.
LOCATION .
                                                       -ROLLS,
                                                                                                           .ENGINEER.
ROLLS  S/N.
                                                                              .COASTDOWN DATE.
INERTIA
WEIGHT,
Ib
1750
2000
2250
2500
2750
3000
3500
4000
4500
5000
5500
over
5500
ABS HP
AT SO MPH
WO/AC
7.7
8.3
8.8
9.4
9.9
10.3
11.2
12.0
12.7
13.4
13.9

14.4
COAST
DOWN
TIME
S
13.80
14.63
15.53
16.15
16.87
17.86
18.98
20.24
21.52
22.66
24.03

23.20
FINAL
HP
FROM
Camp.

—
	
—
	
—
—
—
—
—
—

—
FINAL
TIME OF
COAST
DOWN

	
	
—
	
—
—
—
—
	
—

—
INDICATED
HP
AT 50
MPH

	
	
—
	
—
—
—
—
	
—

—
FRICTION
HP
AT SO
MPH

	
. 	
—
	
	
	
	
	
	
—

—
ABS HP
AT SO
MPH
W/AC
8.47
9.13
9.68
10.34
10.89
11.33
12.32
13.20
13.97
14.74
15.29

15.84
Run a sufficient number of coastdowns to verify that W AC switch is increasing horsepower by 10%, as indicated in Table 2.

-------
25.122
                                                                  APPENDIX D
                                          CRITICAL FLOW  ORIFICE (CFO)  PROPANE INJECTION
                                                      DATA AND CALCULATION SHEET

               CVS (MANF.-NUMBER) = 	DATE

               ENGINEER 	REMARKS 	
                                                                                         &oro
-------
                                                    APPENDIX E
                             HAND CALCULATION FORM-1975 FEDERAL TEST PROCEDURE
                                                                                                              25.123
AMBIENT CONDITIONS
                                                           CORRECTED BAG CONCENTRATIONS
Corrected Barometric Prestura (PJ — jn Hg
Wet Bulb Temperature IT | — °r
Dry Bulb Temperature (Td) - °f
CONSTANT VOtUME SAMPLER PARAMETERS
Phase 1 Phaie 2
Average Delta P, in H.O
Average Flow, HJ/r»v
Average P|u, in H,O
Average T,u, °f
TJU, T,0 4- 460. R
Dilution Air Temp, Dry Bulb
Dilution Air T.mp, W.t Bulb
Dilution Air Relative
Humidify (R) %
CVS Revolutions, rev
BAG CONCENTRATIONS
Dilution Bog
HCd, ppm


CO, , V.
V
Samplt Bog
HC , ppm

NO * ppm
CO, , •/.
*t
Facility Date
TEST PHASE CONCENTRATIONS
HCe.nc = HC. - HCdC - '/OF)
COconc=CO, -C0d(l - I/OF)
NO^co,* = NO" - NO" (' - '/OF)
Phase 1 Phase 2
1/DF
(1 _ I/OF)
Hr.
wrjl 1 /OF)
Hf
HC Ppm
CO.
COj ( 1 1 /DF)
CO

NO j
NO j { 1 1 /DF)
NO
NO , , ,,. ppm
CO,
wJd
CO,, n i /Df\
CO,
'.
CO,
'cane
Facility 	 Date— 	 	
Dilution Bog COd - ( 1 0.000323 R) CO,
R Phase 1 Phase 2 Phase 3
0.000323 R
Pkmf 1 1 - 0.000323 R
COj

COJr ppm

Sample Bag CO, = (1 - 0.0 1925 CO, - 0.000323 R) CO,

CO,

0.01925 COj


CO
COr. ppm

DILUTION FACTORS
Df 13'4
CO, + (HC, + CO,) 10 '
HC, enters into this equation as ppm carbon equivalent.
HC
CO
HC + CO
CO, 4. (HC + CO ) 10 •
Of

Phase 3
NO« HUMIDITY CORRECTION FACTOR
Phase 1 Phase 2 Phase 3
p
T
T
p
Pj
. . - A
p
4147 8 P
P P
H
0 0047 (H 75)
1 0 0047 (H 75)

*h
p


	 Facility 	 Do»« 	

-------
25.124
                                                                        APPENDIX E
                                  HAND CALCULATION FORM —1975 FEDERAL TEST PROCEDURE (continued)
                      ABSOLUTE  INLET PRESSURE
                                                                    Phot. 1           Pho.t 2           Phau 3
                        P,n (absolute) = Pb - P,n, 13.596
                        Pm
                        P,n 13.596
                        Pb
                        P]n (absolute}

                      CORRECTED CVS  FLOW PER  PHASE
                                                          CVS Flo. ,V,,,,,, = V0  X         X       X r.y,
                        vo                                         	
                        P,n(abs), 29.92                              	
                        528/T,,,,                                    	_
                        revs                                        	
                        Vmll. Sid ft'                                 	

                      NO,  HUMIDITY CORRECTION  FACTOR
                        P,  = -4.14438 10  ' 4-  5.76645 10 ' T, - 6.32788 10 ' T.»
                             -f- 2.12294 10 »TJ - 7.85415 10 ' T,4 + 6.55263 10
                        A = 3.67 10 4(1  + 0.00064(T. - 32)1
                        P, = P. -  AP,,(Tj-T.)
                             4347 8 P,

                                       1
                         "    I  - 0.0047(H -  75)
                            P  100
                        R = 	 where P, from first equation above using T, instead of Tw.
                      Facility _	.	,	Date	


                      PHASE MASS

                        HC,,,,,,  = Vm|i x HC	„. X  16.33  X 10 «
                        CO,,,,,, = V,,,,, x CO,.,,,,,. X 32.97 x  10 '
                        NO,,,,,,, =  V	 x NO,,,,,,,. X 54.16 X 10  » X K,,
                        CO,,,,,,, = Vml, x CO,,,,,,, X 51.81 X  10 '
                                                                    Phau 1           Phase 1           Phot* 3

                        V,,,,,                                        	       	       	
                        HC	                                      	       	       	
                        HC,,,,,,,  g                                   	       	       	
                        CO,,,,,,.                                     	       	       	
                        CO,,,,,,,, g                                   	       	       	
                        NO,,,,,,,                                    	       	       	

                        NO     , 9                                 	       	       	
                        CO,,	                                    	       	       	
                        CO,,,,,,., g                                 	       	       	
                      WEIGHTED MASS
                        Weighted Moss = 0.43 Phase I  Mass + Phase 2 Mass + 0.57 Phase 3 Mass
                                                              HC               CO              NO,              CO,
                        0.43 Phase 1 Mass                   	        	       	       	
                        1.00 Phase 2 Mass                   	        	       	       	
                        0.57 Phase 3 Mass                   	        	       	       	
                        Weighted Mass, g                    	        	       	       	
                        Weighted Emissions,
                        grams/mile (Hand Calc)
                        Weighted Emissions,
                        grams/mile (Comp Calc)
                        Difference
                                                                (Computer —  Hand Calculation)
                                                 % Difference =  	            	 X 100
                                                                      Hand Calculation
                      Facility	,	Date

-------
         APPENDIX F
EPA HIGHWAY DRIVING CYCLE
     TIME-SPEED TRACE
25.125
Tim*
0
I
2
3
4
5
6
7
8
9
10
11
12
13
U
13
16
17
18
19
20
21
22
23
24
IS
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
mph
0.0
0.0
0.0
2.0
4.9
8.1
11.3
14.5
17.3
19.6
21.8
24.0
25.8
27.1
28.0
29.0
30.0
30.7
31.5
32.2
32.9
33.5
34.1
34.6
34.9
35.1
35.7
35.9
35.8
35.3
34.9
34.5
34.6
34.8
35.1
35.7
36.1
36.2
36.5
36.7
36.9
37.0
37.0
37.0
37.0
37.0
37.0
37.1
37.3
37.8
38.6
39.3
40.0
40.7
41.4
42.2
42.9
43.5
44.0
44.3
44.5
44.8
44.9
45.0
45.1
45.4
45.7
46.0
46.3
46.5
46.8
46.9
47.0
47.1
47.7
47.3
47.2
47.1
47.0
46.9
46.9
46.9
47.0
47.1
47.1
47.2
47.1
47.0
46.9
46.5
km/h
0.0
0.0
0.0
3.2
7.9
13.0
18.2
23.3
27.8
31.5
35.1
38.6
41.5
43.6
45.1
46.7
48.3
49.4
50.7
51.8
52.9
53.9
54.9
55.7
56.2
56.5
57.5
57.8
57.6
56.8
56.2
55.5
55.7
56.0
56.5
57.5
58.1
58.3
58.7
59.1
59.4
59.5
59.5
59.5
59.5
59.5
59.5
59.7
60.0
60.8
62.1
63.2
64.4
65.5
66.6
67.9
69.0
70.0
70.8
71.3
71.6
72.1
72.3
72.4
72.6
73.1
73.5
74.0
74.5
74.8
75.3
75.5
75.6
75.8
76.0
76.1
76.0
75.8
75.6
75.5
75.5
75.5
75.6
75.8
75.8
76.0
75.8
75.6
75.5
74.8
Tint*
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
no
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
mph
46.3
46.2
46.3
46.5
46.9
47.1
47.4
47.7
48.0
48.2
48.5
48.8
49.1
49.2
49.1
49.1
49.0
49.0
49.1
49.2
49.3
49.4
49.5
49.5
49.5
49.4
49.1
48.9
48.6
48.4
48.1
47.7
47.4
47.3
47.5
47.8
47.9
48.0
47.9
47.9
47.9
48.0
48.0
48.0
47.9
47.3
46.0
43.3
41.2
39.5
39.2
39.0
39.0
39.1
39.5
40.1
41.0
42.0
43.1
43.7
44.1
44.3
44.4
44.6
44.7
44.9
45.2
45.7
45.9
46.3
46.8
46.9
47.0
47.1
47.6
47.9
48.0
48.0
47.9
47.8
47.3
46.7
46.2
45.9
45.7
45.5
45.4
45.3
45.0
44.0
km/h
74.5
74.4
74.5
74.8
75.5
75.8
76.3
76.8
77.2
77.6
78.1
78.5
79.0
79.2
79.0
79.0
78.9
78.9
79.0
79.2
79.3
79.5
79.7
79.7
79.7
79.5
79.0
78.7
78.2
77.9
77.4
76.8
76.3
76.1
76.4
76.9
77.1
77.2
77.1
77.1
77. 1
77.2
77.2
77.2
77.1
76.1
74.0
69.7
66.3
63.6
63.1
62.8
62.8
62.9
63.6
64.5
66.0
67.6
69.4
70.3
71.0
71.3
71.5
71.8
71.9
72.3
72.7
73.5
73.9
74.5
75.3
75.5
75.6
75.8
76.6
77.1
77.2
77.2
77.1
76.9
76.1
75.2
74.4
73.9
73.5
73.2
73.1
72.9
72.4
70.8
Tim*
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
mod
43.1
42.2
41.5
41.5
42.1
42.9
43.5
43.9
43.6
43.3
43.0
43.1
43.4
43.9
44.3
44.6
44.9
44.8
44.4
43.9
43.4
43.2
43.2
43.1
43.0
43.0
43.1
43.4
43.9
44.0
43.5
42.6
41.5
40.7
40.0
40.0
40.3
41.0
42.0
42.7
43.1
43.2
43.4
43.9
44.3
44.7
45.1
45.4
45.8
46.5
46.9
47.2
47.4
47.3
47.3
47.2
47.2
47.2
47.1
47.0
47.0
46.9
46.8
46.9
47.0
47.2
47.5
47.9
48.0
48.0
48.0
48.0
48.0
48.1
48.2
48.2
48.1
48.6
48.9
49.1
49.1
49.1
49.1
49.1
49.0
48.9
48.2
47.7
47.5
47.2
km/h
69.4
67.9
66.8
66.8
67.8
69.0
70.0
70.7
70.2
69.7
69.2
69.4
69.8
70.7
71.3
71.8
72.3
72.1
71.5
70.7
69.8
69.5
69.5
69.4
69.2
69.2
69.4
69.8
70.7
70.8
70.0
68.6
66.8
65.5
64.4
64.4
64.9
66.0
67.6
68.7
69.4
69.5
69.8
70.7
71.3
71.9
72.6
73.1
73.7
74.8
75.5
76.0
76.3
76.1
76.1
76.0
76.0
76.0
75.8
75.6
75.6
75.5
75.3
75.5
75.6
76.0
76.4
77.1
77.2
77.2
77.2
77.2
77.2
77.4
77.6
77.6
77.4
78.2
78.7
79.0
79.0
79.0
79.0
79.0
78.9
78.7
77.6
76.8
76.4
76.0
Tim*
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
mph
46.7
46.2
46.0
45.8
45.6
45.4
45.2
45.0
44.7
44.5
44.2
43.5
42.8
42.0
40.1
38.6
37.5
35.8
34.7
34.0
33.3
32.5
31.7
30.6
29.6
28.8
28.4
28.6
29.5
31.4
33.4
35.6
37.5
39.1
40.2
41.1
41.8
42.4
42.8
43.3
43.8
44.3
44.7
45.0
45.2
45.4
45.5
45.8
46.0
46.1
46.5
46.8
47.1
47.7
48.3
49.0
49.7
50.3
51.0
51.7
52.4
53.1
53.8
54.5
55.2
55.8
56.4
56.9
57.0
57.1
57.3
57.6
57.8
58.0
58.1
58.4
58.7
58.8
58.9
59.0
59.0
58.9
58.8
58.6
58.4
58.2
58.1
58.0
57.9
57.6
km/h
75.2
74.4
74.0
73.7
73.4
73.1
72.7
72.4
71.9
71.6
71.1
70.0
68.9
67.6
64.5
62.1
60.4
57.6
55.8
54.7
53.6
52.3
51.0
49.2
47.6
46.3
45.7
46.0
47.5
50.5
53.8
57.3
60.4
62.9
64.7
66.1
67.3
68.2
68.9
69.7
70.5
71.3
71.9
72.4
72.7
73.1
73.2
73.7
74.0
74.2
74.8
75.3
75.8
76.8
77.7
78.9
80.0
81.0
82.1
83.2
84.3
85.5
86.6
87.7
88.8
89.8
90.8
91.6
91.7
91.9
92.2
92.7
93.0
93.3
93.5
94.0
94.5
94.6
94.8
95.0
95.0
94.8
94.6
94.3
94.0
93.7
93.5
93.3
93.2
92.7
Tim*
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
mph
57.4
57.2
57.1
57.0
57.0
56.9
56.9
56.9
57.0
57.0
57.0
57.0
57.0
57.0
57.0
57.0
57.0
56.9
56.8
56.5
56.2
56.0
56.0
56.0
56.1
56.4
56.7
56.9
57.1
57.3
57.4
57.4
57.2
57.0
56.9
56.6
56.3
56.1
56.4
56.7
57.1
57.5
57.8
58.0
58.0
58.0
58.0
58.0
58.0
57.9
57.8
57.7
57.7
57.8
57.9
58.0
58.1
58.4
58.9
59.1
59.4
59.8
59.9
59.9
59.8
59.6
59.4
59.2
59.1
59.0
58.9
58.7
58.6
58.5
58.4
58.4
58.3
58.2
58.1
58.0
57.9
57.9
57.9
57.9
57.9
58.0
58.1
58.1
58.2
58.2
km/h
92.4
92.1
91.9
91.7
91.7
91.6
91.6
91.6
91.7
91.7
91.7
91.7
91.7
91.7
91.7
91.7
91.7
91.6
91.4
90.9
90.4
90.1
90.1
90.1
90.3
90.8
91.2
91.6
91.6
92.2
92.4
92.4
92.1
91.7
91.6
91.1
90.6
90.3
90.8
91.2
91.9
92.5
93.0
93.3
93.3
93.3
93.3
93.3
93.3
93.2
93.0
92.9
92.9
93.0
93.2
93.3
93.5
94.0
94.8
95.1
95.6
96.2
96.4
96.4
96.2
95.9
95.6
95.3
95.1
95.0
94.8
94.5
94.3
94.1
94.0
94.0
93.8
93.7
93.5
93.3
93.2
93.2
93.2
93.2
93.2
93.3
93.5
93.5
93.7
93.7
Tim*
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
mph
58.2
58.1
58.0
58.0
58.0
58.0
58.0
58.0
57.9
57.9
58.0
58.1
58.1
58.2
58.3
58.3
58.3
58.2
58.1
58.0
57.8
57.5
57.1
57.0
56.6
56.1
56.0
55.8
55.5
55.2
55.1
55.0
54.
54.
54.
54.
54.
54.
55.0
55.0
55.0
55.0
55.0
55.0
55.1
55.1
55.0
54.9
54.9
54.8
54.7
54.6
54.4
54.3
54.3
54.2
54.1
54.1
54.1
54.0
54.0
54.0
54.0
54.0
54.0
54.0
54.0
54. t
54.2
54.5
54.8
54.9
55.0
55.1
55.2
55.2
55.3
55.4
55.5
55.6
55.7
55.8
55.9
56.0
56.0
. 56.0
56.0
56.0
56.0
56.0
km/h
93.7
93.5
93.3
93.3
93.3
93.3
93.3
93.3
93.2
93.2
93.3
93.5
93.5
93.7
93.8
93.8
93.8
93.7
93.5
93.3
93.0
92.5
91.9
91.7
91.1
90.3
90.1
89.8
89.3
88.8
88.7
88.5
88.4
88.4
88.4
88.4
88.4
88.4
88.5
88.5
S8.5
88.5
88.5
88.5
88.7
88.7
88.5
88.4
88.4
88.2
88.0
87.9
87.5
87.4
87.4
87.2
87.1
87.1
87.1
86.9
86.9
86.9
86.9
86.9
86.9
86.9
86.9
87.1
87.2
87.7
88.2
88.4
88.5
88.7
88.8
88.8
89.0
89.2
89.3
89.5
89.6
89.8
90.0
90.
90.
90.
90.
90.
90.
90.
   (Table continued next page)

-------
25.126
                                                                 APPENDIX F
                                                      EPA HIGHWAY DRIVING CYCLE
                                                       TIME-SPEED TRACE (continued)
Tim*
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
-561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
mph
56.0
56.0
56.0
56.0
56.0
56.0
56.0
55.9
55.9
55.9
55.8
55.6
55.4
55.2
55.1
55.0
54.9
54.6
54.4
54.2
54.1
53.8
53.4
53.3
53.1
52.9
52.6
52.4
52.2
52.1
52.0
52.0
52.0
52.0
52.1
52.0
52.0
51.9
51.6
51.4
km/h
90.1
90.1
90.1
90.1
90.1
90.1
90.1
90.0
90.0
90.0
89.8
89.5
89.2
88.8
88.7
88.5
88.4
87.9
87.5
87.2
87.1
86.6
85.9
85.8
85.5
85.1
84.7
84.3
84.0
83.8
83.7
83.7
83.7
83.7
83.8
83.7
83.7
83.5
83.0
82.7
Tim*
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
moh
51.1
50.7
50.3
49.8
49.3
48.7
48.2
48.1
48.0
48.0
48.1
48.4
48.9
49.0
49.1
49.1
49.0
49.0
48.9
48.6
48.3
48.0
47.9
47.8
47.7
47.9
48.3
49.0
49.1
49.0
48.9
48.0
47.1
46.2
46.1
46.1
46.2
46.9
47.8
49.0
km/h
82.2
81.6
81.0
80.1
79.3
78.4
77.6
77.4
77.2
77.2
77.4
77.9
78.7
78.9
79.0
79.0
78.9
78.9
78.7
78.2
77.7
77.2
77.1
76.9
76.8
77.1
77.7
78.9
79.0
78.9
78.7
77.2
75.8
74.4
74.2
74.2
74.4
75.5
76.9
78.9
Tim*
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
552
653
654
655
656
657
658
659
mph
49.7
50.6
51.5
52.2
52.7
53.0
53.6
54.0
54.1
54.4
54.7
55.1
55.4
55.4
55.0
54.5
53.6
52.5
50.2
48.2
46.5
46.2
46.0
46.0
46.3
46.8
47.5
48.2
48.8
49.5
50.2
50.7
51.1
51.7
52.2
52.5
52.1
51.6
51.1
51.0
km/h
80.0
81.4
82.9
84.0
84.8
85.3
86.3
86.9
87.1
87.5
88.0
88.7
89.2
89.2
88.5
87.7
86.3
84.5
80.8
77.6
74.8
74.4
74.0
74.0
74.5
75.3
76.4
77.6
78.5
79.7
80.8
81.6
82.2
83.2
84.0
84.5
83.8
83.0
82.2
82.1
Tim*
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
mph
51.0
51.1
51.4
51.7
52.0
52.2
52.5
52.8
52.7
52.6
52.3
52.3
52.4
52.5
52.7
52.7
52.4
52.1
51.7
51.1
50.5
50.1
49.8
49.7
49.6
49.5
49.5
49.7
50.0
50.2
50.6
51.1
51.6
51.9
52.0
52.1
52.4
52.9
53.3
53.7
km/h
82.1
82.2
82.7
83.2
83.7
84.0
84.5
85.0
84.8
84.7
84.2
84.2
84.3
84.5
84.8
84.8
84.3
83.8
83.2
82.2
81.3
80.6
80.1
80.0
79.8
79.7
79.7
80.0
80.5
80.8
81.4
82.2
83.0
83.5
83.7
83.8
84.3
85.1
85.8
86.4
Tim*
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
mph
54.2
54.5
54.8
55.0
55.5
55.9
56.1
56.3
56.4
56.5
56.7
56.9
57.0
57.3
57.7
58.2
58.8
59.1
59.2
59.1
58.8
58.5
58.1
57.7
57.3
57.1
56.8
56.5
56.2
55.5
54.6
54.1
53.7
53.2
52.9
52.5
52.0
51.3
50.5
49.5
km/h
87.2
87.7
38.2
38.5
89.3
90.0
90.3
90.6
90.8
90.9
91.2
91.6
91.7
92.2
92.9
93.7
94.6
95.1
95.3
95.1
94.6
94.1
93.5
92.9
92.2
91.9
91.4
90.9
90.4
89.3
87.9
87.1
86.4
85.6
85.1
84.5
83.7
82.6
81.3
79.7
Tim*
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765














mph
48.5
47.6
46.8
45.6
44.2
42.5
39.2
35.9
32.6
29.3
26.8
24.5
21.5
19.5
17.4
15.1
12.4
9.7
7.0
5.0
3.3
2.0
0.7
0.0
0.0
0.0














km/h
78.1
76.6
75.3
73.4
71.1
68.4
63.1
57.8
52.5
47.2
43.1
39.4
34.6
31.4
28.0
24.3
20.0
15.6
11.3
8.0
5.3
3.2
1.1
0.0
0.0
0.0














INSTRUMENTATION  AND  TECHNIQUES  FOR
VEHICLE  REFUELING  EMISSIONS
MEASUREMENT—SAE  J1045
    SAE  Recommended Practice
Report of Automotive Kmissions and Air Pollution Ixmimmer approved August
  Scope—This SAE Recommended Practice describes a procedure for measur-
ing the hydrocarbon emissions occurring during the refueling of passenger cars
and light trucks.'It can be used as a method for investigating the effects of
temperatures, fuel characteristics,  etc., on refueling emissions in the  labora-
tory. It also can be used for determining the reduction in emissions achieved
with emission control hardware. For this latter use, standard temperatures,
fuel volatility,  and fuel quantities  are specified.
  Central Discussion—Refueling losses  are  made  up of the following indi-
vidual losses:
       (a) Displaced fuel tank  vapor.
       (b) Entrained fuel droplets in the displaced vapor.
       (c) Liquid spillage.
       (d) Nozzle drip during  insertion and removal from the filler neck.
  Experience has shown that displaced vapor normally is 90'7o or more of the
total loss. The amount of displaced vapor is known to be affected  by a number
of factors, particularly dispensed fuel temperature, Reid vapor pressure, and
the degree to which dispensed  fuel and  displaced vapor come into contact.
  The measurement  facility described in this SAE Recommended Practice
includes a sealed enclosure. The enclosure is identical  to that  described in
SAE J171, except for the minimum length specified and  that a refueling hose
and nozzle has been added. The hydrocarbon measuring instrument is iden-
tical to that of SAE Jl 71.  This  technique is used to measure the total loss for
the four sources listed above.
  The recommended practice includes the following sections:
     1. Test  Fuel
    2. Test  Facilities and Equipment
    3. Measurement Method
    4. Information and Data to be Recorded.
  /. Test Fuel
    1.1 The test fuel should have a  Reid vapor pressure  of 'J.O ± 0.5 psi
(62 ± 3 kPa). To describe the fuel being used  adequately,  it should be in-
spected for these properties:
                Property
Distillation
IBP
 5%
10%
15%
20%
30%
40%
50%
90%
FBP
Reid vapor pressure, psi (Pa)
Hydrogen-carbon ratio0
                                               ASTM Till Method
                                                    D 86
                                                    D323
                                                    0 1018
  aThe hydrogen-carbon (H/C) ratio it required for the calculation of lonet uting the enclosure
method. The H/C ratio will be different for vapor louet at compared to liquid lotiei. Therefore,
the H/C ratio thould be meaiured for both condenied vapor and for the teit fuel. Judgment
ihoutd be uied in interpolating between the two valuet for individual lesti. H/C ratio can alter-
nately be meaiured by /3-roy absorption, which it quick and accurate dee Jacobi, et al., Anal
Chem., Vol. 28, March 1956).

-------
  25.162
  tor signal from a gas chromaiograph. which shows deflections to indicate, for
  example, (he presence of individual hydrocarbons.
      11.14 Hang-Up—A  term  to describe  the phenomena  whereby higher
  molecular weight hydrocarbons are retained in the sample train, causing an
  initial low analyzer reading, followed by higher readings in subsequent tests.
  Excessive hang-up causes errors in the analysis of the hydrocarbons in ex-
  haust  gas.
O     11.15 Gas Chromalograph—An  instrument  commonly  used to detect
  individual gases  in complex gaseous mixtures. NOTE:  In  automobile exhaust
  gas analvsis such instruments  can be  used 10 separate and determine  the
  concentration  of individual hydrocarbon species in a complex hydrocarbon
  mixture.
0     11.16 Hexane  Equivalent  Concentration (ppm hexane)—The  concen-
  tration of a propane calibrating gas in terms of its  hexane equivalent concen-
  tration. For .NDIR, hexane equivalent concentration has been established as
  propane concentration times 0.52. For FID. hexane equivalent concentration
  equals propane concentration times 0.50.
0     11.17 Idle Speed—The engine's low idle speed as specified by the manu-
  l.ujurer.
     11.19 Intermediate Speed—The peak  torque speed or 60'« of the rated
  ••peed, whichever is higher.
0     11.20 Mode—A particular event (for example, acceleration, deceleration.
  i mise. or idle I of a vehicle test cycle.
~c>     11.21  Nondispersive  Infrared (NDIR)—Electromagnetic radiation used
  .is ilie  light source in NDIR instruments capable of measuring CO, CCX. NO.
  and unburned hydrocarbons in exhaust gas.
0     11.22 Nondispersive  Ultraviolet  (NDUV)—Electromagnetic radiation
  used as the light source in  NDUV instruments capable of measuring NO.,
  concentrations in exhaust gas.
0     11.23 Non-Methane Hydrocarbons (N'MHC)—All organic hydrocarbon
  i (impounds, excluding methane, present in an exhaust sample.
O     11.24 Smoke Opacimeter—An optical instrument designed  to measure
  the opacity of diesel- exhaust gases. The  full  flow of exhaust gases passes
  through  the optical unit. One  such smoke opacimeter is described  in SAE
  )'-'55 (June. 1971].
     11.27 Opacity—The  fraction of light transmitted from a source which is
  prevented from  reaching the  observer or  instrument  receiver,  in  percent
  (Opacity  = |1  — Transmittancc| X 100).
&     11.28 Photographic Smoke Measurement—A measurement technique
  which relies upon an instrumental or visual comparison of the photograph
  image of a smoke plume with an established scale of blackness or opacity |.
  determine  the opacity of the original smoke plume.
      11.29  Probe—A device inserted into some portion of an engine or vehic>
  system in order to obtain a representative gas or liquid sample.
      11.30  Proportional Sampling—A method of obtaining a composite san-,.
  pie of exhaust gas representative of all driving modes in a test  cycle. Thj
  sample, when analyzed,  will represent the average molar concentration of»
  constituent properly  weighted for mass flow rates.
      11.31  Rated Power—The maximum brake power output of an engine, in,
  horsepower or kilowatts, as stated by the manufacturer.
      11.32  Rated Speed—The engine speed at which the manufacturer specj.,
  fics the rated brake power of an engine.
      11.33  Rated Torque—The maximum torque produced by an engine, a,
  stated by the manufacturer.
      11.34  Reid  Vapor Pressure—The vapor pressure of gasoline  at 100'F,
  (37.8°C) determined in  a  special bomb in the presence of a volume of m
  which occupies four times the volume of liquid fuel (ASTM procedure D323i
      11.35  Reference Cell—That portion of the NDIR  instrument which:
  provides the  reference signal to the detector.
      11.36  Resolution—The minimum distinguishable reading,  for a given t
  trace width and scale combination, expressed as a percent of full-scale.
      11.37  Sample Cell—That portion of the NDIR  instrument which con-(
  lains (he sample gas being analyzed.
      11.38  Sampling—The technique of obtaining  an accurate sample of i
  exhaust gas for analysis.  Sampling may be grab, continuous, or proportional
      11.39  Test Cycle—A  sequence of an engine or vehicle operating moda(
  usually designed to simulate road usage of the vehicle.
      11.40  Test  Fuel—A fuel for use  in  a given test  and having specifict
  chemical and physical properties required for that test.
      11.41  Transmitlance—That fraction of light transmitted from a source, t
  through a  smoke-obscured path, which reaches  the observer or ins(rumtm
  receiver.
                     /                    Opacity \
                     ITransmittance = 1	-I
                     V                       100   /
      11.42  Variable Dilution Sampling—Use Constant Volume Sampling  e
      11.43  Variable Rate Sampling—A technique to obtain an exhaust sanvt
  pie which  takes a specific and constant fraction (for example, '/10oo) °f '^
  total exhaust  stream at  each mode so that when the aggregate sample is
  analyzed for its molar constituents, it is weighted in proportion to the averap
  flow rate through the cycle.
      11.44  Visual Smoke  Measurement—A measurement technique which*
  relies  upon human observation  of an engine's  smoke plume  to  rate tna'
  plume's appearance agains( an esoblished scale of blackness or opaci(y (usu'
  ally a gray scale on eilher a transparent or opaque white base).
  METHANE  MEASUREMENT  USING GAS
  CHROMATOGRAPHY—SAE J1151  OCT88
SAE  Recommended  Practice
  Report of (he Automotive Emissions Committee, approved August 1976, completely revised June 1983. and reaffirmed October 1988.
    /. Purpote—This SAE Recommended Practice provides a means for
 a  batch measurement of the methane concentration in light-duty vehi-
 cle exhaust samples. Nonmethane  hydrocarbon concentration  can  be
 obtained by  subtracting the methane concentration from the total hy-
 drocarbon concentration obtained by a separate measurement made in
 accordance with accepted practices such as SAE J1094, J254, or a" cur-
 rent Federal Test Procedure.1
    2. Scope—This SAE Recommended Practice describes instrumenta-
 tion for determining the amount of methane  in air and exhaust gas.
    3. Section!—The remainder of this practice is divided into the fol-
 lowing sections:
       4.  Definitions of Terms  and Abbreviations.
       5.  Equipment.
       6.  Principle of Operation.
       7.  Instrument Operating Procedure.
       8.  Instrument Performance Specifications.
       9.  Maintenance.
   1 See Code of Federal Regulations. Title 40 Protection of Rnvironment. Part
 86. Subpart B, F.mission Regulations for 1977 and Later Model Year New Light-
 Duty Vehicles and New Light-Duty Trucks: Test Procedures (40 CFR 86.101 et
 seq.)  (as possibly amended by the Federal  Register).
    4. Definition! of Terms and Abbreviations
      4.1  Terms Used
    4.1.1  Vehicle emission terms are defined in SAE Jl 145.
    4.1.2  CARRIER GAS—A gas that acts as a passive vehicle to transporl
  the sample through a gas chromatograph column.
    4.1.3  GAS CHROMATOCRAPHV—A separation  technique in which a
  sample in the gaseous state  is carried by a  flowing gas (carrier (!'•
  through a tube (column) containing stationary material. The stationary
  material performs the separation by means of its differential affinity '°
  the components of the sample.
      4.2  Abbreviations and Symbols
      °C            —degree(s) Celsius
      CH4          —methane
      CO           —carbon  monoxide
      COj          —carbon  dioxide
      cm            —centimeter(s)
      CVS          —constant volume sampler
      FID          —flame ionization detector
      Fig.           —figure
      g              —gram
      GC           —gas chromatograph(ic)
      h              —hour(s)

-------
                                                                                                                             25.163
    HC           —hydrocarbon(s)
    ID           —inside diameter
    in            —inch
    kPa           —kilopascal
    NMHC       —nonmethane hydrocarbon(s)
    min          —minute(s)
    m            —meter
    mm          —millimeter(s)
    jim           —micrometer(s)
    Oj           —oxygen
    OD           —outside diameter
    ppm          —parts per million
    ppm C        —parts per million carbon
    psig          —pound(s) per square inch, gage
    s             —second(s)
    scfh          —standard cubic foot per hour
    SAE          —Society of Automotive Engineers. Inc.
    SS           —stainless steel
    7c            —percent
  5. Equipment
    5.1 Safety Precautions—Flammable FID fuel (containing hydro-
gen) and potentially toxic 29J  CO in exhaust gas are vented from this
instrument at low flow rates of approximately 80 cmVmin (0.2 scfh).
At these low flow rates, there should not normally be a hazard  trom
these gases, but precautions should be observed to insure dilution of
these potentially hazardous vented gas streams.
  The instrument uses flammable fuel and the precautions specified by
the manufacturer  should be observed.
  The sample bypass line in the instrument has a How of about  2000
cmVmin (4 scfh) of automotive exhaust gas. This flow should be dis-
charged outside of the building or  into an  adequately ventilated  area.
    5.2 Instrument—A gas chromatograph is  used  to  separate the
methane from the other  constituents of an exhaust gas sample. The
concentration of methane is determined with a FID. A typical suitable
gas chromatograph is described in this section.
    5.3 Component Description—The schematic diagram  in Fig.  1
shows a typical  gas chromatograph assembled to routinely determine
methane. The following components are typically used.
  5.3.1 VALVE, VI—Sample injection and  switching valve, should be
low dead volume,  gas tight, and heatable to at least 150°C.
  5.3.2 VALVE, V2—Used to provide supplementary  fuel to the FID
burner.
                           OVEN
                          5.3.3 VALVE. V3—Used to seleci span gas. sample, or  no flow.
                          5.3.4 VALVE, V'4—Used as a restrictor to match the How resistance
                        of the Porapak N column.
                          5.3.5 VALVE. V5—Used as a restrictor to match the flow resistance
                        of the Molecular Sieve column. This valve allows equalizing backflush
                        and foreflush flow rates through the Porapak column.
                          5.3.6 VALVE, V6—Used  as  a restrictor for controlling  the rate of
                        sample flow to fill the sample loop.
                          5.3.7 PRESSURE REGULATOR. PR1. AND PRESSURE CAGE.  Gl—To con-
                        trol flow rate of  the fuel which is also the carrier gas.
                          5.3.8 PRESSURE REGULATOR. PR2.  AND PRESSURE  GAGE.  G2—Back-
                        pressure regulator for controlling the rate of sample flow to the sample
                        loop in conjunction with valve V6. Should be adjusted in the pressure
                        range from 7 to  34 kPa (I  to 5 psig).
                          5.3.9 GC COLUMN—Porapak N. 180/300 urn (equivalent to 50/80
                        mesh), 610 mm (2 ft) length X 2.16 mm (0.085 in) ID X 3.18 mm ('/8
                        in) OD SS, to separate air. CH«, and CO from the other sample constit-
                        uents. The column is conditioned 12 h or more at 150°C  with carrier
                        gas  flowing prior to initial use. Valve VI should be in the fill/backflush
                        position during the conditioning.
                          5.3.10 GC  COLUMN—Molecular  Sieve  Type   13X.   250/350  urn
                        (equivalent to 45/60  mesh), 1220 mm  (4 ft) length  X2.16 mm (0.085
                        in)  ID, 3.18  mm  ('/8 in) OD SS. to separate methane from oxygen, ni-
                        trogen, and  CO. The column is conditioned 12 h or more at  150°C
                        with carrier gas flow prior to initial use. Valve VI should be in the  fill/
                        backflush  position during the conditioning.
                          5.3.11 -SAMPLE  LOOP—A  sufficient  length of SS tubing to obtain ap-
                        proximately  1 cmj volume.
                          5.3.12 OVEN—To maintain columns  and valves at a stable tempera-
                        ture for analyzer operation, and to condition columns at 150°C.
                          5.3.13 VALVE ACTUATOR—To actuate sample injection and switching
                        valve.
                          5.3.14 VALVE  PROGRAMMER—Timing unit to control valve actuator.
                          5.3.15 DRYER—To remove water and other  contaminants  which
                        might be present in the carrier gas, a filter dryer containing Molecular
                        Sieve is used. If it is a visual indicating type, the dryer is replaced when
                        the need is indicated. Otherwise, it is replaced or reconditioned month-
                        ly. If the dryer has a metal body, it can be reconditioned after remov-
                        ing it from the  instrument by flowing approximately 50  cmVmin of
                        dry nitrogen through the dryer while it is heated  to 150'C in an oven
                        for 12 h.
             TO
         VENTILATED
            AREA
                                                                                                                     FUEL
                                                                                                                     INLET
                                                                                                                         VENT
                       VALVE (VI)
                       POSITION
                          • INJECT
                         - FILL / BACKFLUSH
SAMPLE
                                                                         SPAN GAS

                                          FIG. 1—INSTRUMENT TO MEASURE METHANE

-------
 25.164
  5.3.16 RKSTRICTOR.  R3—For controlling the rate of air flow to FID.
  p.3.17 PRESSURE REGULATOR.  PR3—Used  with pressure gage.  G3,
and restrictor. R3. to  control air flow to FID.
  5.3.18 FILTERS  Fl.  F3.  F4—Sintered  metal  filters to prevent  grit
from entering the instrument.
  5.3.19 FILTERS F2, F5—Sintered metal filters in the sample stream to
prevent grit from entering the pump or instrument. Should be of suffi-
ciently large area to have a pressure drop of less than  15 kPa (2 psi) at
the bypass flow rate used of approximately 2000 cmVmin (4 scfh).
  5.3.20 PLMP—Used to bring sample to gas chromatograph.
  5.3.21  VALVE. V7—Used  with flowmeter.  FM1, to regulate  bypass
sample flow rate. The  bypass sample flow rate should be fast enough to
flush out the entire sample line in a time less  than the GC analysis time
so that while an analysis is being made, the  sample  loop is filled with
the next sample and is ready for the next analysis cycle. A typical by-
pass flow rate would be 2000 cmVmin (4 scfh).
  5.3.22 VALVE, V8—Used  with flowmeter.  FM1, to equalize  bypass
flow rates of span gas and sample.
  5.3.23 RECORDER—The  recorder or  other  readout device  should
have an input compatible with the FID analyzer output, an accuracy (in-
cluding the effects of  deadband and linearity) of ±0.259?  of full scale
or better, a span step  response time of 0.4 s  or  less,  and a chart speed
of approximately 25 mm/min (1 in/min).
  5.3.24 FID—The flame ionization detector generates an electrical
current proportional to the flow rate of methane through the burner.
The associated electrometer  amplifier acts as a current to voltage con-
verter and should have an electronic time constant of less  than 0.20 s.
  6. Principle of Operation—The instrument  (Fig.  1)  measures the
methane concentration in  a  sample swept from  a fixed volume sample
loop by a carrier gas stream when the valve (VI) is in the inject posi-
tion. The carrier gas can be blended FID fuel.  The stream enters the
Porapak N  gas chromatographic  column which temporarily  retains
NMHC. COj, and water, and passes air, methane, and CO to the  Mo-
lecular Sieve column.  As soon as  all of the methane elutes from the
Porapak N column and has passed through valve VI toward the Molec-
ular Sieve column, the Porapak  N column is backflushed to waste by
switching  the valve (VI) to  the  fill/backflush position.  Switching VI
also starts filling the sample  loop with the next sample. The Molecular
Sieve column separates the methane from the air and CO before pass-
ing it  to the FID. The FID produces a signal peak proportional to the
methane concentration  in the sample.  As soon  as the methane peak
passes through the FID. valve VI can be switched back to the inject po-
sition  to inject the next sample. A complete cycle, from injection of one
sample to injection of  a second, can be made  in 30 s. Automation of in-
jection  and  backflush switching  assures reproducible peak times and
shapes and is easily accomplished.
  7. Instrument Operating Procedure
    7.1 In general, the manufacturer's instructions  for operation of
the instrument  or gas chromatograph should be followed.
    7.2 Component Assembly—The assembly  of the components for
the instrument  is shown in Fig.  1. The sample and switching valve VI.
restrictor valves V4 and V5, sample loop, and the two GC columns are
installed in the  oven. The outlet  of valve V5 and the outlet from valve
VI. port 8 must discharge directly into an  open area at  atmospheric
pressure where there  can be no effluent build-up. The  other  compo-
nents are connected  outside the oven  with all connecting  tubing of
minimum length. After all of the connections have been  made, as indi-
cated in Fig. 1, leak check the fittings and the instrument is ready for
adjustment of operating parameters.
    7.3 Initial Adjustment of Operating Parameters—The timing se-
quence is determined  by the flow rates of the carrier  gas, the gas hold-
up  volume of the system, and the column temperature. Typical flow
rates at several instrument locations identified by the encircled numer-
als in  Fig. 1  are given  in Table 1. The following procedure would typi-
cally be followed to determine satisfactory flow rates of  the assembled
system and the switching times of  the valves.
  7.3.1  Set the initial  operating parameters.  Record oven temperature,
gas pressures, and flow  rates for later reference.
    7.3.1.1 Sample—Adjust  the flow of  span gas or sample with V8 or
V7 so  that the flow discharged to the vent is about 2000 cm'/min (4
scfh).  Adjust backpressure regulator PR2 so that gage G2 reads from
7 to 34 kPa (1  to 5 psig). Readjust span gas or  sample bypass flow to
2000  cmVmin.  With valve  VI  in the  fill/backflush position, adjust
valve  V6 so that the flow from port 8 of valve VI is 80-100 cmVmin.
    7.3.1.2 Carrier Gas—Mixed  fuel is recommended to minimize the
number  of  gases  required  for  vehicle  exhaust measurements since
mixed fuel is also used  for total hydrocarbon measurements (see SAE
J1094). Mixtures from 38 to 559? hydrogen with the diluent being heli-
                     TABIE 1 —TYPICAL FLOW RATES .
Location (Fig. 1)
1 . Sample Bypass Vent
2. Burner Air
3. Total Burner Fuel"
4. Backflush
5. Sample
6. Makeup Fuel0
7. Porapak N Column0
8. Molecular Sieve Column0
Vary* VI Position
Inject
Fill/Bockflush
Flaw Rat* — cm'/min
(room pressure and temperature!
2000
400
100
60
95
30
70°
70°
2000
400
100
60
90
30
60
70°
 "Fuel: 40% H,/60% He.
 ° These flow rates were measured at location 3 with valve V2 closed.
um or nitrogen have been found to be acceptable. The carrier gas mix-
ture should contain less than 0.5 ppm  C HC. (The oxygen peak height
(see Fig. 2) is not a direct response to oxygen, but is caused by a syner-
gistic effect of O2 on  the HC impurity in the mixed  fuel, therefore it
is an approximate  indicator of the hydrocarbon concentration in the
fuel.)
  With sampling and switching valve (VI) in the  inject position  and
valve V2 closed, adjust pressure regulator PR1 so that the carrier flow
rate through the columns into the FID burner is about 70  cmVmin.
Typically, the pressure regulator PR1  will be set at approximately 140
kPa (20 psig). The  flow is readily measured with a soap bubble  flow-
meter.  The  elapsed time from  sample injection to the appearance of
the oxygen peak (Fig.  2) is primarily a  function of the carrier flow rate.
Turn valve VI  to the fill/backflush position. Adjust  valve V4 so that
the carrier flow rate through the Molecular Sieve column and into the
FID burner is the same (within 29c) as when valve VI is in the inject po-
                     K)       15       20      25       30

                           TIME  (s)
   INJECT
                       FILL/BACKFLUSH

           FIG. 2—TYPICAL GAS CHROMATOGRAM

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                                                                                                                               25.165
sition. Check the backflush flow rate through valve V5 to confirm that
it is approximately equal (within 3090 to the flow rate through the col-
umns into the FID burner.
    7.3.1.3 Column Conditioning—With valve VI  in fill/backflush posi-
tion  and carrier gas flowing, adjust oven temperature to 150°C and
condition columns for a minimum of 12 hours. After conditioning, ad-
just oven temperature to about 55°C.
    7.3.1.4 Additional Fuel—Open valve V2 to provide a total hydro-
gen flow to the FID burner of about 40 cmVmin (for  example, 100
cmVmin of 40<7C  H2/60'7c He  fuel).
    7.3.1.5 Air (Should Contain Less Than 0.5 ppm C HC)—Set  the pres-
sure regulator PR3 so that the air flow to the FID burner is  approxi-
mately ten  times the hydrogen flow.
    7.3.1.6 Column Oven  Temperature—The column oven  should be
maintained at a constant temperature. A temperature of about  55°C
will allow an  analysis time of 30 seconds. The  temperature can be ad-
justed between 35 and 75°C in order to give a desired analysis  time. Al-
low time for oven temperature  to stabilize before making measure-
ments. The temperature control setting that maintains 150°C for use
in conditioning the GC columns should be  ascertained before column
installation.
  7.3.2  TIMING SEQUENCE—The analysis starts with valve VI in the fill/
backflush position. In this position, the sample loop is  flushed and filled
with sample (flow rate 80-100 cmVmin). With a typical  instrument, it
was found that  if the sample select valve, V3, selected the next sample
at least  6 s before sample injection, the sample loop was fully flushed
and hence a longer flush and fill time gave  the same  analytical results.
The sample is injected by switching valve VI  into the inject  position.
The sample passes into the  Porapak  N column from which air elutes
first and then methane. Carbon dioxide, higher hydrocarbons, and wa-
ter vapor are retained longer in the Porapak N column.  It is necessary
to leave valve VI  in the inject position only  long enough for all the
methane to elute from  the Porapak N column. If valve VI is in the in-
ject position too long, CO? will also elute from the Porapak N column,
pass  onto the Molecular Sieve column, be absorbed  by  and gradually
deactivate the Molecular Sieve column. The optimum time for switch-
ing is found by  determining the minimum time required  for maximum
methane response to be obtained.  With a typical instrument  at a col-
umn flow rate of 73 cmVmin. it was found  that if valve VI was manu-
ally switched from inject to fill/backflush 6  s after injection, the meth-
ane peak height was 539J of its ultimate height measured with a later
valve switching. If valve VI was switched 7  s after injection, the meth-
ane peak height was 959J of its  ultimate height, and if valve VI was
switched 8  s after injection, the ultimate peak height was reached. For
this instrument, valve VI was programmed to stay in the  inject position
for 9 seconds. The gases in order of elution from the Molecular  Sieve
column  into the FID are oxygen, which gives a  small peak: nitrogen;
methane, which gives the peak that is measured: and  CO, which elutes
well  before the next methane peak. The FID does not respond to the
nitrogen and carbon monoxide. Fig. 2 shows a gas chromatogram ob-
tained with this system. (In  normal use a slower chart speed is used.)
With valve VI in the fill/backflush position, the Porapak N column is
backflushed to  waste to clean it out for the next sample. Also during
this time, the sample loop is flushed and filled  with the next sample to
be analyzed. After most of the methane peak has eluted into  the FID,
valve VI can be switched to inject the next sample. The last  traces of
methane can finish eluting while the next sample is being injected. In
a typical instrument, the cycle time was 30  seconds.
    7.4 Calibration—Typically, analyzer response is  linear (not neces-
sarily passing through the origin) with the methane content of the sam-
ple. However, this should be verified for each analyzer prior  to its in-
troduction  into service  and  at  monthly  intervals  thereafter.  The
linearity should also be verified  whenever the FID burner  is serviced
and whenever the fuel carrier gas  supply is changed. A  series of four
or more calibration gases, containing methane  of known  concentration
in air, covering the range of concentrations within which sample gases
may be expected to fall, should  be used for calibration. Optionally, a
flow blender may be used to blend a single calibration  gas with  zero
grade air to provide a series of intermediate calibration gases.. The
methane impurity of the zero grade air should  be determined  and con-
sidered in the calculation of the methane concentration of the interme-
diate gases. Obtain  the least-squares  straight line regression of the
methane concentration in the calibration gas as a function of methane
peak height (or, if used, peak area). It is recommended that the datum
point obtained with zero grade air should not be included in the regres-
sion. The reason is that if the methane concentration in the zero grade
air is lower than the methane concentration in  the carrier gas, the sam-
ple of zero grade air will produce a negative methane peak. Many peak
height or peak area measuring schemes cannot correctly determine the
height or area of the negative peak. For each range calibrated, it the
deviation of the calibration points from the regression line is 2C? or less
or within 0.1  ppm methane of the  value of each data point (excluding
zero), then  linearity is confirmed and a linear equation may be used to
determine the methane concentration.  Otherwise, attempt to  find and
correct  the cause of the non-linearity. If necessary, the best fit non-
linear equation which represents the  data to within 2$ (or  0. 1  ppm
methane) of each point  may be  used to determine  the concentration.
    7.5  Emission  Measurement Procedure — Each  series  of sample
and dilution air bags from one vehicle test  should be preceded with a
measurement of zero gas and span gas. If the instrument output for
these  gases is not the same as  during the last calibration, an electrical
or computational correction to the  instrument output should be made.
Re-check zero. Six methane analyses can be  made in  4 minutes. A mea-
surement of zero gas and span  gas following the test series  which  is
within 2% of full scale from the initial values will confirm that there
was no substantial instrument drift  during the measurement of the test
samples. The instrument should  be located near the CVS  in  order to
minimize the length of tubing. Samples are pumped directly from the
bag via  a Teflon or stainless steel tube to the sample inlet.
    7.6  Data Analysis — The methane peak height is used as a measure
of the amount of methane. Peak height is the distance from  the peak
maximum to the peak baseline. The peak baseline is  defined as the pla-
teau immediately preceding the peak. (Alternatively, the methane peak
area, as  determined with an integrator,  can be used as a measure of the
amount  of  methane.) Methane concentrations are  measured  directly,
NMHC  concentrations can be determined by the difference between an
independent  total  hydrocarbon  concentration measurement  and the
methane concentration.
  7.6.1  METHANE — The  following example  for a linear analyzer  illus-
trates the method of calculation:

    Span — 18.9 ppm C  methane — 50.0 chart divisions
    Bag Analysis
      Methane — 25.0 chart divisions
    Bag Concentration Calculation
                        25.0
      Methane — 18.9 X JTJJ-JJ = 9.45  ppm C

For calculating the mass of methane  by a  method  analogous to that
used in  the Federal Test Procedure'  for hydrocarbons, the  methane
density  at 20°C (68°F) and 101.32 kPa (760 mm Hg) pressure should
be taken to be 0.667 kg/m3 (18.89 g/ft3).
  7.6.2  NONMETHANE  HYDROCARBON — NMHC data  analysis is accom-
plished  with calculation  techniques similar to those  used for total HC
CVS bag emission data analysis. The following example for a linear an-
alyzer illustrates the method of calculation:

    Span — 18.9 ppm C  methane — 50.0 chart divisions
    Bag Analysis
      Methane — 25.0 chart divisions
      Total HC — 82.56 ppm C
    Bag Concentration Calculations
                        25.0
      Methane — 18.9 X -    = 9.45 ppm C
      NMHC — (total  HC (ppm C) — methane (ppm C))
               = 82.56 — 9.45 =73.11 ppm C
The exhaust sample and the dilution-air bags should be analyzed and
the NMHC concentrations used for calculation of mass emissions as di-
rected in the Federal  Test Procedure1 for hydrocarbon.
  It can be noted that, in general, the sum of the methane mass emis-
sions and the calculated NMHC mass emissions will not exactly equal
the total calculated HC  mass emissions. This is because the FID mea-
sures carbon mass and not hydrocarbon mass. The  relation between
these two masses depends on the hydrogen/carbon ratio of the hydro-
carbons in the exhaust gas and this is not determined for each sample.
Instead a nominal  value for the hydrogen/carbon  ratio is assumed in
the Federal Register.
   See Code of Federal Regulations, Title 40 Protection of Environment. Part
86, Subpart B, Emission Regulations for 1977 and Later Model Year New Light-
Duty Vehicles and New Light-Duty Trucks: Test Procedures (40 CFR 86.101 et
seq.) (as possibly amended by the Federal Register).

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25.166
  S.  Instrument Performance Specifications
    8.1 Baseline Noise—The instrument shall be run for 20 min with
valve VI  remaining in the fill/backflush position. The peak-to-peak
noise and drift of the baseline shall not exceed the equivalent of 0.16
ppm methane.  (With a typical instrument, the peak-to-peak noise and
drift was 0.07 ppm  methane.)
    8.2 Precision—A  span gas containing about 20 ppm  methane in
air shall be read at  least 25 times. Wait one  cycle period (typically 30
s) between starting the flow of span gas and  trie first rotation of valve
V1 into the inject position.  The standard deviation of the series of span
gas readings shall not exceed 0.10 ppm methane. (With a typical instru-
ment the  standard deviation of a series of span gas readings was 0.02
ppm methane.) Since the first reading of the  series is most  apt to show
an offset,  the magnitude of the difference between the first determina-
tion  of the series and the mean of the series shall be no greater than
0.14 ppm methane or 3.3 standard deviations, whichever is greater.
    8.3 Column Resolution—The methane retention time (paragraph
9.2.1) divided by  the peak  width at half height (paragraph  9.2.2) shall
exceed 10.5.  (In Fig. 2 this quotient is 11.5.)
  9.  Maintenance
    9.1 Valve VI Position—Except when actually injecting a sample.
valve VI should be kept in  the fill/backflush position so as  to minimize
possible contamination  of the Molecular Sieve column by effluent from
the Porapak  N column.
    9.2 Column Performance
  9.2.1  The methane retention  time, which  is the elapsed time from
sample injection (sample injection is when valve  VI rotates from thf
fill/backflush position to the inject position)  to the appearance of th?
methane peak maximum, should be measured when the instrument is
placed in service and at weekly intervals thereafter. A change in the re-
tention  time from its initial value gives  an indication that the column
has deteriorated or that the initial conditions have changed. If the rf.
tention time has changed by more than 109£,  the cause should be iden-
tified and corrected. Check oven temperature. Check or condition tht
dryer as described in paragraph 5.3.15. Check the carrier gas flow ram
against  the  flow rates  initially  measured  as described  in paragraph
7.3.1.2. Check  for leaks. Condition the columns as described in para-
graphs 5.3.9 and 5.3.10.
  9.2.2  Time the width of the methane peak at half of its peak height
using a stopwatch or a gas chromatogram  obtained with the recorder
running at a fast speed of at  least 0.3 m/min (1 ft/min). Perform this
test when the instrument is first placed in service and at monthly inter-
vals thereafter.  A change in the peak width at half height of more than
15% suggests that the cause be identified as in paragraph 9.2.1.
    9.3 Dryer  Conditioning—If an indicating type dryer is  used, ii
should be checked monthly and  replaced if exhaustion is indicated. If
a non-indicating type dryer is used, it should be  replaced or recondi-
tioned monthly. (See paragraph  5.3.15.)

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