EPA-AA-EOD-84/2
Non-Proportional Sample Rates in a Critical Flow Venturi
Constant Volume Sampler:
Effects on Federal Emission Test Fuel Economy
Performed by
Engineering Operations Division
Written By
Carl Paulina
January, 1982
Correlation Group
Testing Programs Branch
Engineering Operations Division
Office of Mobile Source Air Pollution Control
Ann Arbor, Michigan 48105
-------
EPA-AA-EOD-84/2
Non-Proportional Sample Rates in a Critical Flow Venturi
Constant Volume Sampler:
Effects on Federal Emission Test Fuel Economy
Performed by
Engineering Operations Division
Written By
Carl Paulina
January, 1982
Correlation Group
Testing Programs Branch
Engineering Operations Division
Office of Mobile Source Air Pollution Control
Ann Arbor, Michigan 48105
-------
Executive Summary
Background
The Constant Volume Sampler (CVS) is used in conjunction with gas analyzers to
measure automobile exhaust gas constituents emitted during a Federal Test
Procedure (FTP) driving sequence. The raw automobile exhaust gases are mixed
with dilution air, sampled, and collected in evacuated airtight bags. The
bagged samples are then analyzed for percent or parts per million (PPM)
composition.
Critical flow venturi (CFV) constant volume samplers (CVS) are used by the
Environmental Protection Agency. A detailed explanation of CFV properties and
theories is contained in Attachment H. If the analysis bag sample flow rate
remains constantly proportional to the total dilute exhaust flow rate, the
bagged sample represents average emission concentrations for that portion of
the test. This value is then applied to the total calculated volume of dilute
exhaust to calculate the total quantity of emission emitted by the vehicle
during that portion of the test. The purpose of this study is to examine the
possible effects on test results (primarily fuel economy) when sample flow is
not constantly proportional to dilute vehicle exhaust bulkstream flow rate in
a CFV, CVS.
Test Types
Two separate test programs were used in this study. The first program used
one vehicle and one sampling system. Half the tests were run with the sample
rate remaining constantly proportional to the total vehicle dilute exhaust
flow. The other half were run with a sample rate which did not remain
constantly proportional to the total dilute exhaust flow. The test results
were then analyzed as two-sample unpaired test groups.
The second program was run on two separate vehicles. Each vehicle test was
run using two separate sampling systems, sampling the same dilute exhaust
stream. One of the sampling systems operated with the sample rate constantly
proportional to the total dilute exhaust flow while the other did not. The
sample system which was operating at a flow remaining constantly proportional
to the total dilute exhaust flow was randomized throughout the testing
sequence. The test results were then analyzed as two-sample paired test
groups. "The second program's vehicles and CVS operating parameters were
chosen to assess the scope of possible effects. Both test programs used
modified Federal Emission Test Procedure tests (2 bag hot city) and highway
fuel economy tests (HWFET). Hot tests were used to both minimize vehicle test
to test variability and to generate a population large enough to insure
statistical confidence within a reasonable length of time.
Results
The results of the study indicate that slightly higher fuel economy values
were generally achieved when the sample probe flow rates remained constantly
proportional to the total dilute exhaust flow rate. Overall, the measured
mean differences appeared to be 2% or less. The second test program, with
manufacturer-supplied vehicles, exhibited a 0.6% to 1.2% mean difference
depending on the vehicle and test type (2 bag hot city, or HWFET). Although
the observed offsets are statistically significant, extreme care had to be
-------
-2-
taken to minimize or eliminate all possible vehicle/site variabilities and
inaccuracies. The magnitude of the observed offsets could be masked by
Federal Register acceptable tolerances on test parameters. This study used
vehicle engine size, loading, and CVS sample probe outlet/inlet operating
pressure ratio to try to characterize minimum/maximum possible fuel economy
effects. However, the test results indicate that the complex inter-dependent
relationships occurring in vehicle emission testing prevent mathematical
prediction of results by these aforementioned parameters.
Recommendations
It is recommended that sample probe pressures be monitored to ensure the
sample probes are operating at a flow rate which remains constantly
proportional to the total dilute exhaust flow.
-------
-3-
Non-Proportional Sample Rates in a Critical Flow Venturi
Constant Volume Sampler:
Effects on Federal Emission Test Fuel Economy
Background
The Constant Volume Sampler (CVS) is used in conjunction with gas analyzers to
measure automobile exhaust . gas constituents emitted during a Federal Test
Procedure (FTP) driving sequence. The raw automobile exhaust gases are mixed
with dilution air, sampled, and collected in evacuated airtight bags. The
samples are then analyzed for percent or parts per million (PPM) composition.
These measured concentrations are then applied to the calculated total volume
of dilute exhaust flow for that portion of the test sequence.
The critical flow venturi (CFV) constant volume samplers (CVS), used by the
Environmental Protection Agency, employ two CFV's each. The main or
bulkstream CFV is used as a flow metering device to quantify the total volume
of vehicle exhaust/dilution (dilute exhaust) air mixture passed through a CVS
during a Federal Register city or highway test sequence. The second or sample
CFV is used to insure that the analysis bag sample flow during a test is in a
constant volumetric proportion to the total exhaust volume throughout the test
sequence. A detailed explanation of CFV properties and theories are contained
in Attachment H. If the analysis bag sample flow rate remains constantly
proportional to the total dilute exhaust flow rate; the bag can be collected,
analyzed, and used as average emission concentrations for that portion of the
test. This value is then applied to the total calculated volume of dilute
exhaust' to calculate the total quantity of emission emitted by the vehicle
during that portion of the test. The purpose of this study is to examine the
possible effects, if any, on test results (primarily fuel economy) caused by
the sample probe flow not being constantly proportional to dilute vehicle
exhaust bulkstream flow rate.
Initial Investigations
Flow curves for two sample probes contained in EPA CVS's were characterized
i'. The graph of flow rate versus the ratio of the outlet to inlet pressure
is contained in Attachment A. The sample probes graphed reached an "in choke"
flow condition at a ratio of pout/pin °f approximately 0.60. A
numerically higher ratio will cause the sample probe to drop out of choke
flow, resulting in fluctuation of sample flow with fluctuation of sample
conditions. Once a CFV drops to an "out of choke" flow condition, it is
beyond the scope of this report to predict what operating, parameter will
affect the flow rate or by how much.
Actual pressure measurement of the CVS sample probes were recorded to set
outlet to inlet pressure ratios P0ut/^in were numerically higher than the
0.60 ratio discussed above. The values were measured using both a u-tube
manometer and strain gauge pressure transducers. The pressure transducers
were then used to monitor sample probe CFV inlet and outlet pressures during a
vehicle test.
I/ Unpublished Study performed by C. Ryan and B. Harbowyof EOD, Calibration &
Maintenance.
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-4-
Sample probe outlet pressure was recorded on two vehicle tests and fluctuated
0.6 inch of mercury (Hg) on one and 0.9 inch Hg on the other while inlet
pressures remained constant. As a result the Pout/Pin fluctuated during
.the emission test sequence. The observed fluctuations suggested a possible
increase of sample flow rate during high acceleration portions of a test and
lower flow rates during idle and lower accelerations. Vehicle emission maps
with respect to vehicle speed are potentially variable from vehicle to
vehicle. CVS dilution ratio variation will change with engine size. Finally,
the pressure ratio fluctuations were not exactly synchronized with vehicle
accelerations. Consequently, it is not possible to state in which direction
the sample flow rate changed during higher and lower vehicle emission output.
Test Plan One Design
To establish what emission measurement effects are caused by the
non-proportional flow rate fluctuations in the CVS sample probe CFV, a
sequence of tests were run on a repeatable vehicle used at EPA for
site-to-site comparisons. A series of ten highways and ten 2-bag hot city
tests were run on the EOD repeatable vehicle. In each test sequence, five
tests were run with the sample probe operating "in choke" flow and five were
run with the probe operating "out of choke" flow. For the "out of choke" flow
tests, a Pout/Pin equivalent to a ratio of 0.83 was used. An "in choke"
ratio of approximately 0.55 was used. In order to minimize possible
sequential results, all tests were run using two consecutive tests in one
condition followed by two consecutive tests in the opposite condition for
eight tests. On the final two tests, probe conditions were alternated. The
sequence for the two test types and the pertinent vehicle parameters are
listed as Test Plan 1.
Test Plan 1
Vehicle Parameters:
Inertia Weight 3500 Pounds
Actual Horsepower 12.8 Horsepower
Fuel System Fuel Injection
Drive System Rear Wheel
Test Sequence:
HWFET Hot City. 2-Bag Tests
1 In choke 1 Out of choke
2 In choke 2 Out of choke
3 Out of choke 3 In choke
4 Out of choke 4 In choke
5 In choke 5 Out of choke
6 In choke 6 Out of choke
7 Out of choke 7 In choke
8 Out of choke 8 In choke
9 In choke 9 Out of choke
10 Out of choke 10 In choke
In Choke Pout:/Pin ~ 0.55
Out of Choke Pout/pin ~ 0.83
-------
-5-
Test Plan One Results
The results were compared as two test groups in each test sequence (2 bag hot
city, HWFET). Comparisons of the "in choke", and "out of choke" probe test
results are contained in Attachment B. A two-tailed Student's t-Distribution
test was used to calculate a confidence interval for the offset between the
means at the 0.90 confidence level with 5 tests in each configuration. The
assumptions are independent, normally distributed populations and pooled
variances.
The calculated intervals for % difference unchoked - choked x ^00
choked
between means are:
Hot tests 1.5% +_ 1.1% higher fuel economy "in choke"
than "out of choke".
HWFET 2.0% + 1.6% higher fuel economy "in choke" than "out
of choke".
A sequential graph of test fuel economy is contained in Attachment C.
Attachment D is a comparison graph of the mean and standard deviations of fuel
economy for the two samples in each test sequence.
Test Plan Two Design
To further minimize the chance of vehicle test-to-test influences, a sequence
of tests were run using two separate probes and sample trains sampling in the
same CVS bulkstream on individual vehicle tests. Two separate vehicles were
used for the Test Plan Two sequence. The samples of each individual vehicle's
exhaust were then processed as two tests using the same analyzer. In the "out
of choke" flow tests, a POut/^in °f approximately 0.90 was used. This was
numerically higher than the ratio used in test plan one. An "in choke" ratio
of approximately 0.50 was used for that portion of the tests. The two sample
probes were altered in and out of "choke flow" randomly. One test was run
with both probes in an "in choke" condition at the start of each sequence
(2-bag hot city and HWFET) to quantify possible sample train offsets. If a
difference was found, additional tests were run to come up with a mean offset
to subtract from subsequent "in" and "out" of choke flow pairs. The test
sequences and pertinent vehicle parameters are listed under Test Plan 2.
Test Plan 2
Vehicle I Parameters:
Inertia Weight 2500 Pounds
Actual Horsepower 6.0
Fuel System Carburetor
Drive System Front Wheel
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-6-
Test Sequence:
HWFET
Probe
1 In
2 In
3 Out
4 In
5 In
6 Out
1
Choke
Choke
of Choke
Choke
Choke
of Choke
Probe 2
In Choke
Out of Choke
In Choke
Out of Choke
Out of Choke
In Choke
Hot City 2-Bag Tests
Probe 1
1
2
3
4
5
6
In Choke
Out of Choke
In Choke
In Choke
In Choke
In Choke
Probe 2
In Choke
In Choke
Out of Choke
Out of Choke
Out of Choke
Out of Choke
In Choke Pout/Pin ~ °'50
Out of Choke P,
out
' ^
0.90
Vehicle 2 Parameters:
Inertia Weight
Actual Horsepower
Fuel System
Drive System
Test Sequence:
HWFET
Probe 1
1
2
3
4
5
6
7
8
In Choke
In Choke
Out of Choke
In Choke
In Choke
In Choke
Out Choke
In of Choke
Probe 2
In Choke
Out of Choke
In Choke
In Choke
Out of Choke
Out of Choke
In Choke
In Choke
4500 Pounds
13.0
Carburetor
Rear Wheel
Hot City 2-Bag Tests
Probe 1
1
2
3
4
5
6
7
8
In Choke
Out of Choke
In Choke
Out of Choke
In Choke
In Choke
Out of Choke
Out of Choke
Probe 2
In Choke
In Choke
In Choke
In Choke
Out of Choke
Out of Choke
In Choke
In Choke
In Choke Pout/pin ~ °'50
Out of Choke P0ut/pin ~ °*90
We used these test sequences both on a "large" and a "small" engine vehicle to
bracket maximum and minimum expectable offsets. At least five pairs of "in
choke" to "out of choke" comparisons were generated for each car and test
sequence.
Test Plan Two Results
The results are listed in Attachment E. Time sequence plots of paired
differences in fuel economy are contained in Attachment F. Attachment G is a
tabular representation of the means, 0.90 confidence intervals, and confidence
that a_ difference exists.
A student's t-distribution test for paired data was used to calculate a 0.90
confidence interval that the expectable mean offset will fall within on the
pairs in each configuration. The assumptions are that the differences are
from a random, normally distributed population.
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-7-
The calculated intervals for the mean percent offset between "in choke" and
"out of choke" are:
(4500 Ibs, 13.0 Actual Horsepower)
2 bag hot city 0.6% -f 0.4% higher fuel economy "in choke"
than "out of choke".
HWFET 1.2% + 0.9% higher fuel economy "in choke"
than "out of choke".
(2500 Ib, 6.0 Actual Horse Power)
2 bag hot city 0.6% + 0.4% higher fuel economy "in choke"
than "out of choke".
HWFET 0.8% + 0.5% higher fuel economy "in choke"
than "out of choke".
Conclusions and Recommendations
Non-proportional CFV-CVS sample flow can affect vehicle calculated fuel
economy. We are unable to discern a mathematically predictable pattern to the
effect on calculated fuel economy based on parameters monitored in this study
(i.e. engine size, loading, and sample probe outlet/inlet operating pressure
ratios). It is recommended that CFV sample probe parameters be monitored to
ensure that sample probes remain in a "choke" flow condition. This will
ensure a sample flow rate which remains constantly proportional to total
dilute exhaust flow.
-------
-8-
Attachments
A - CVS, CFV Sample Probe Flow Profile
B - Test Program 1 Results
C - Test Plan 1 Sequential Test Fuel Economies
D - Test Plan 1 Fuel Economy Mean and Standard Deviation
E - Test Plan 2 Results
F - Test Plan 2 Sequential Test Absolute Fuel Economies and Percent Differences
G - Test Plan 2 Fuel Economy Results and Statistics
H - CFV Theoretical Analysis
-------
i ri i< >M }t\ i ~n in 1 tirrll
.MI i out A i it* ?i»nt i INI rfl-.ir.pi ;-MVII v
n
-------
ATTACHMENT B
LHB CORRELATION SUGARY
PROCESSED: NOV I3i 1981
VOLVO PRuBE HOTS
VIN VOLVO RFJ'CA
INERTIA «T 3500 ACTUAL h? 12,8
> LAB
\ __
SAMPLE CFV CHOKED
HC CO NOX C02 FE BARO HUH NXFC DBL H3L TLOSS
l< G/'Hl >l (MPG)(IN-HG) (SRAINS
/LB)
0.606 4,72 2.29 423, 20.5 29,15 49,56 0,89
STANDARD DEV, .0152 0,887 ,083 4, 0,1 0.042 4.072 .015
C.V.Z 2,5 18,8 3,6 0,9 0.7 0,14 8,22 1,71
l<(GRAMS)>!
SAHPLE CFV 'UNCKOKEH 5
KEAN 0.614 4,52 2,26 430, 20.2 29.03 49.30 0.89
STANBARli DEV. .0195 0.438 .047 5. 0,2 0,182 9.033 .036
C.V.Z 3,2 9,7 2,1 1,1 1,1 0,63 1S.32 3,98
DIFF, 2 1, -4, -1, 2, -1, -0. -1, -0,
C.V.Z IS THE COEFFICIENT OF VARIATION, (STD. DEV,/SEAN XlOO),
lilFF.Z IS THE DIFFERENCE OF THE KEANS BETb'EEH THE KFF: ASH EPA LABS. (KFR-EPA/EF'A ?100).
-------
> LAB CORRELATION SUGARY - TEST DATA
>"
-.-___---__._-_ _ «.«_ ___v _._..__
V :
>LAJ«, EPA - Choked VEHS VOLVO PROBE HOTS VIHJ VOLVO REPCA INERTIA
> DATE TESTND TYPE HC CO NOX 032 FE DRIVER DYHO OCOH IHP BARD HUM NXFC
_-._ --m-Tir _ ... m -.:._, ___. _. .. «.__ __ ....
>10-OB-B1 B10905 HOT 0,590 4,20 2,19 424, 20,5 30398 D004 12475.0 10,8 29,10 44,160.87
MO-06-81 810906 HOT 0,600 4,40 2,21 422, 20,6 3089E H004 12490,0 10,8 29,10 47,62 0,89
MO-09-81 810909 HOT 0.610 4.40 2.36 428. 20.3 30S9B D004 12540.0 10,8 29,18 54,88 0,91
MO-09-81 810910 HOT 0,600 4,30 2.35 424. 20.5 30898 D004 12555,0 10,8 29,18 51.81 0,90
MO-16-B1 810912 HOT 0,630 6,30 2.34 417. 20,7 30893 D004 12650.0 10.8 25.21 49,35 0,89
> K (G/KI) ->l IHPB) , UN-HG) (GRAINS
> . /LE)
> MEAN 0.606 4.722,29423.20,5 29,15 49.560,89
> STANDARD DEV, ,01520.887,083 4, 0,1 ", 0,042 4.072,015
> C.V.Z 2,5 18,8 3,6 0,9 0.7 . 0,1 8,2 1,7
> ' BAG DATA
> DATE TESTND TYPE DYNO SITE ~HC 2 3 CO ' 2 3 NOX 2 3 C02 2
MO-OB-81 810905 HOT D004 A6oY6",591 0.590 0,0 4.34 4,07 0,0 2,81 1,61 0.0 420, 427,
MO-OS-SI 810906 HOT D004 A002 0.601 0.595 0.0 4,19 4,58 0,0 2.8? 1,59 0;0 421, 424,
MO-09-31 810909 HOT D004 A002. '0,620 0,595 0,0 4,34 4,55 0,0 3,13 1,64 0.0 431. 426,
>lP-P?-8i 5)0*10 HOT I'OOs A002 0.613 0.591 0,0 4.22 4.32 0,0 3.14 1.63 0.0 426. 422.
MO-lo-Si SM9l2 HUT DOW A062 0,631 0,636 0,0 5,92 6,59 0,0 3,161,590.0 417,416,
> . : (ALL G/KI)
' . PROCESSED: NOV is. i?ei
WT: 3500 ACTUAL HP; 12,8
DBL HSL TLOSS
K (GRAHS)-->i .
3 FE 2 3
0, 20,7 20.4 0.0
0, 20,7 20,5- 0,0
0. 20,2 20.4 0.0
0. 20,4 20.6 0,0
0. 20,7 20,7 0,0
K-(HPG) >1
STAKliARl; DEV,
C.V.Z
0.611 0,601 0.0
0.016 0,019 0,0
2,6 3,2 0,0
4,60 4.E2 0,0 3.03 1.61 0,0 423, 423.
0.74 1,01 0,0 0.16 0,02 0.0 6. 4,
16,1 20,9 0.0 5,4 1.4 0.0 1,3 1,0
0, 20,5 20.5 0.0
0, 0.2 0.1 0.0
0.0 1,1 0,6 0,0
> C.V.Z IS THE COEFFICIENT OF VARIATION.(STB, DEV./KEftN 1100).
> D1FF, MS THE DIFFEREHDE OF THE HEAKS STbLcK THE nFR AND EPA LAB, (KFR-EFA/EPA tlOO),
> HDTE: THE COKHENTS PERTINENT TO THESE TESTS ARE LOCATED IK THE LAST TABLE OF THIS APPEHDIX,
-------
LAB-CORRELATION SUMMARY - TEST DATA ' PROCESSED', HOV 18. 1981
>L«P: SAMPLE CFV 'UNCHDKED VEH 5 VOLVO PROBE HOTS
> HATE TESTND TYPE HC CO HOX C02
N ., . .
J .!,.__, . - _ - . .. -_-
>1 0-02-81 810903 HOT 0,580 4,00 2,28 423,
MO-06-81 810904 HOT 0,620 4.40 2.18 433,
MO-08-S1 810907 HOT 0,620 4,60 2,29 435,
MO-OS-61 810908 HOT 0.620 4,40 2,28 431.
MO-14-81 810911 HOT 0,630 5,20 2,29 429.
K Vb/nl) >1
>
>: -MEAN 0.614 4,52,2.26430.
> "STANDARD DEV. .0195 0,438 -.047 5,
> C.V.Z 3.2 9,7 2,1 1,1
> DIFF. 1 1, -4, -1, 2,
> DATE TESTND TYPE DYND SITE HC 2
... , . L .. ,,_«._
MO-02-31 E10903 HOT D004 A002 0.593 0.559 0
MO-06-81 810904 HOT H004 A002 0,643 0.600 0
>1 0-08-81 610907 HOT H004 AG02 0.636 0.613 0
MO-O'd-8; 810703 HOT D004 A002 0.647 0.59S 0
MO-14-81 810911 HOT H004 A002 0,637 0.620 0
FE DRIVER
'20,6
20,1
20.0
20.2
20,2
30898
30398
Z.OS9S
30898
30898
VI N: VOLVO REPCA
DYHO
D004
'D004
H004
H004
D004
ODOM
12407
12448
12506
12519
12577
IHP
,3 10.
.0 10,
.0 10.
,0 10.
,2 10.
(MPG)
20,2
0,2
1.1
-1,
3
,0
.0
,0
,0
.0
BAG DATA
CO
4.03
4.53
4,71
4,47
5.50
2
4.04
4.29
4,49
4.39
5,01
. 3
0,0
0,0
0.0
0,0
0.0'
NOX
3,05
2.93
3,03
3.06
3.04
BARO
8 28.97
8 28,74
8 29.12
8 29.08
8 29,22
INERTIA DTI 3500
HUM
65.25
^6,23
44,10
43.74
47.16
KXFC
0,96
0,88
0,87
0,87
0,88
(IN-HG) (GRAINS
'V
29.03
0.182
0.6
-0.
2 3
1.56 0.0
1.4E 0,0
1.61 0,0
1.56 0.0
1.60 0,0
/IB)
49.30
9,0ii
18,3
-1.
C02
423.
437.
439,
433,
430,
0.89
,036
4,0
-0,
2 .
423,
430.
431.
429.
429.
> (ALLS/HI)
> MEAN 0,632 0,598 0
> STAHIiARIi BEV, 0,023 0,024 0
> C.V.Z 3,6 4.0
> DIFF. 2 3, -1,
,0
,0
0.0
0.
4.65
0.54
11.5
1.
4,44
0.36
8,1
-8,
0,0
0.0
0.0
0,
3,02
0,05
1,7
-0,
1.56 0.0
C.05 0.0
432,
6.
3.3 0.0 1,5
-3. 0
o
* *.*
428,
i.
0,7
1.
DBL HSL
K. tr.r-r.u
3 FE
0. 20,5
0. 19.9
0. 19.8
0, 20,0
0, 20,1
ACTUAL
TLOSS
ir\. _M
2 3
20,6 .0
20.2 0
20,1 0
20,3 0
20,2 0
HP: 12.8
.0
.0
.0
.0
.0
K--(HPG) >l
0, 20,1
0, 0,3
0,0 1,3
0. -2,
20,3 0
0.2 0
0.9 0
-1.
.0
.0
.0
0.
> c,v.: is THE COEFFICIENT OF VARIATION,ISTD, DEV./HEAH tioo),
> EIFF, 1 IS THE "1FFEREKCE OF THE KEANS KTHEEK THE hFR AKD EPA LAB, (KFR-EPA/EPA «00),
> NOTE: THE COHMNTS PERTIKENT TO THESE TESTS ARE LOCATED IN THE LAST TABLE OF THIS APPENDIX.
-------
LAB CORRELATION SUMMARY
PROCESSED: KOV is, i?si
VOLVO PROBE HFET
VIH VOLVO REPCft
INERTIA UT 3500 ACTUAL HP 12,8
LAB
KC CO NOX C02 FE BARO ' HUM NXFC DEL HSL TLOSS
> SAMPLE CFV CHOKED 5
l< G/HI >I(KPG)(IN-KG5 (GRAINS K (6RAKS)-
. ' /LB) .
HEAN / 0,503 3.863,56364,23,929,09 50,350,90
STAKDAPJi DEV. . .0084 0.044 .086 5. 0.3 0,207 3.401 .013
C.V.Z -1.7 1,7 2,4 1,3 1,3 0,71 6,751,45
>
.>
SAMPLE CFV 'UKCHOKED 5.
0,512 3,86 3,70 371, 23.4 28.86 56,47 0,92
MEAN
STANDARD DEV, .0099 0,073 ,208
c.v.z
DIFF, 2
0.3 0.242 3.935 .016
1,9 1,9 5,6 1,4 1.4 0,84 6,97 1.71
2, .-0, 4,
"> -2, -1, .12, 3,
C.V.Z 13 IKE COEFFICIEKT OF VARIATION, (STB. DEV./txAN 1100),
: IS THE DIFFERENCE OF THE KEANS BETb'EEK THE fiF'K AND EPA LABS. (KFR-EPA/EPA 1100).
-------
y
>LAi.; EFA - Choked
Vi»tt» t.rM it- r.«s«r.t" T3TT*T?rP t;" i * * * 'f ' ' -' ~-^f'«'^ *
'in. VULVL- rr.-'Bi nrET Vih, Vw-vj Mpuft
IKESTIA yi; 3500 A-TUALH?: 12.8
TEETKO TYPE HC CC KOX C02 FE DRIVER DYNO CI'QC IH? BARO Hurl NXFC BEL "HEL TLOSS
Xtf-29-31 810693-1 HFET 0,512 3,67 3,50 364, 23,9 30E98 B004 12147.0 10,8 29,25 51,10 0,90
>0?-29-£l £v9-30-£i £10£?S-i HFET C.509 Z.B2 3,70 370. 23/5 17282 KM 12275.0 10,8 29,11 47.54 0,6?
>10-01-6l 810901-1 HFET 0,505 3,?o 3,57 366, 23,7-30898 B004 12355,3 10,3 2B.74 55,51 0,92
> K (G/hl) >l (fiPG) (IH-HG)(GRAINS
> . /LB)
!<(6RAHS)-
>
>
>
>:
C.V.2
0,503 3.86 3.56 364. 23,9
DEV. .0084 0.066 .086 5. 0.3
1.7 1.7 2,4 1.3 1.3
29.09 50,35 0,90
0.207 3.401 .013
0,7 6.8 1,4
LAB CORRELATION SUMMARY - TEST DATA
>LAE; SAMPLE CFV 'UNCHCKED VEH: VOLVO PROBE'HFET
VIN; VOLVO REFCA
PROCESSEDt MOVlSi 1981
INERTIA fc'T; 3500 ACTUAL KPS 12,6
> DATE TESTHO TYPE KC CO NOX CG2 FE DRIVER DYNO OBOH IK? BARO HUH NXFC DEL HSL TLCSS
>09-30-81 B10E95-1 HFET 0.517 3,95 3.73 374, 23.2 172S2 H004 1219B.5 10,8 29,12 56,05 0.92
>09-30
-81 810B96-1 HFET 0,517
SI 6108=9-1 HFET 0,502
81 B10900-1 HFET 0.522
81 810902-1 HFET 0.500
3.92 4,01 377. 23.1 3089c D004 12223.0 10,8 29.11
3.85 3.53 363. 23.9 17232 1:004 12318.0 10.8 23.63
3.78 3,75 372, 23.4 17232 1:004 12327.1 10.8 28,64
3.SO 3.49 369. 23.6 30898 D004 12376.0 10.8 26,73
"(G/HI )----> I (HPG)
53.16 0.91
58.32 0.93
62,19 0,94
52,64 0,90
(IH-HG) (GRAIN'S
/LB)
K(GRAMS)>l
>
/
HEfiH
STANDARD DEV,
C,V,Z
DIFF, 2
0.512 3.86 3.70 371. 23.4
,0099 0,073 ,208 5, 0,3
1.9 1.9 5,6 1,4 1.4
2, -0, 4. 2, -2,
28,86
0,242
0.8
-1,
56.47 0.92
3,935 .016
7,0 1,7
12, 3,
-------
nrr, 20x20 TO
VOLVO REFCA FUEL ECONOMY - SEQUENTIAL TESTS
o
&
a
2
H
n
-------
ATTACHMENT D
I ,' I
IMeJ
i i
S-tan iard-j-
~n~r
MM
i I
ITT
MM
_L_L
i ! I
I i I
-HOX-IESX
i i
I i
I I I
HWFET:
i I I
i i i
i i
I I I
I I I
I ! i
I I i
i I
UNCHOKEtt
j- I i i I
MM
i i
! M i
I I I I
i IT
Mil
MM
i I M
Mil
I i
TT
II M
i M I
III!
I I
! i I
Mi'
! i i
I i I
i i
TT
TTTET
III!
i !
T7TTT
III!
I I i
i i
i i
i i
MM
Mil
i i
20.0 .
-o '
Mil
J_L
i l
! I
-------
LAH CORRELATION SUMMARY - TEST DATA
PROCESSED! NOV 19, 1981
'>: EPA - PAIRED
JATE TESTNO
28-81 011327
?8-81 81132H
-28-81 811329
=28-bl 811330
-13-81 811331
-13-81 811332
-13-81 811333
-13-81 811334
-J3-81 B~il335
-13-81 011336
-13-81 811380
-13-81 811389
-J3-01 811591"
-13-81 811592
-TJ-Bi 8~li593
-13-81 B11594
TESTS
TYPE
HOT
HTT
HOT
H')T
HOT
HnT
HOT
HOT
Ho'f "
HOT
HIT
HOT
HOT
HOT
HOT
HOT
HC
0.162
0.161
0. 148
0.14/
0.254
0.250
0.234
0.237
6.214
0.214
0.20V
0.20V
0.19V
0.19V
0.21 1
0.205
1 t
VEHI COUGAR HOTS VINI 106T084 ' INERTIA WTl 4500 ACTUAL HP 1 13.
CO NOX C02 FE DRIVER DYNO DOOM 1HP BARO HUM NXTC OBL HSL TLOSS
0.61 0.99 546. 16.2 17282 0003 7195.1 10.0 29.29 48.81 0.09
0.60 0.99 546. 16.2 17282 0004 7195.1 0.0 29.29 48.81 0.09
0.43 0.96 544. 16.3 17282 0003 7207.0 0.8 29.29 50.46 6.50 *
0.43 0.96 548. 16,1 17282 0004 7207.0 0.8 29.29 50.46 0.90
1.13 .02 54?. 16.3 22118 0003 7390.1 0.8 29.39 49.93 0.89 *
1.11 .02 543. 16.3 22118 0004 7390,1 0.8 29.39 49.93 n.89
0.00 .09 535. 16.5 2?118 0003 7400.5 0.0 29.40 47.30 0.89 §
0.00 .10 536. 16.5 22118 0004 7400.5 0.8 29.40 47.38 0.89
0.91 .05 529. 16.7 22118 0003 7414.5 0.8 29.36 46.97 O.Ofl
0.90 .04 522. 16.9 22118 0004 7414.5 0.0 29.36 46.97 0.08 f
1.01 .02 532. 16.6 23118 0004 7425.8 0.0 29.34 41.91 0.07
1.02 .02 535. 16.5 23118 0003 7425.8 10.8 29.34 41,91 0.87
0.65 .06 533, 16.6 22118 0003 7432.1 10.8 29.34 42.73 0.87
0.66 .06 537. 16.5 22118 0004 7432.1 10.8 29.34 42.73 0.87
0",54 .05 536. 16.5 22118 0003 7437.6 10.6 29.34 43.12 0.87
0.53 .05 537. 16.5 22118 0004 7437.0 10.8 29.34 43.12 0.87
Ir./MIi % 1 IMPr.l ( 1N-HC.I (r.BAIN<; 1 <--- ( rtR AM5 ) --- > 1
MEAN
STANDARD DEV,
c; v. %
D003 = Probe 2
DOOA = Probe 1
0.20J 0.76 1.03 538. 16.4
.0336 0.234 .041 7. 0.2
16.5 30.9 4.0 1.3 1.3
29.34 46.41 0.88
0.065 3.275 .012
0.2 7,1 1,4
O
O
OJ
o
K)
§ >
a 3
o >
H O
° a
M H
H W
CO
CO
-------
LAB COHHELATION SUMMAHY - BAG DATA
Ji EPA
VLHI COUGAR HOTS
V1NI 106T004
INERTIA WTI 4500
ACTUAL HPI 13.0
)<\TE TESTNO TYPE OYNO SITE HC
CO
MOX
ro2
re 2
?H-B1 811327 HOT D003 A002 0.159 0.16f> 0.0 1.09
;H-BI B1132B HOT 000*. AOO? o.iS7 0.166 0,0 i.oo
-'H-ai BI1329 HOT 0003 A002 0.126 0.16V 0.0 0.00
?H-H1 811330 HOI 0004 AU02 0.126 0.166 0.0 0.01
J-B1 B11331 HOT OOU3 A002 0.363 0.155 0.0 2.03
3-81 H11332 HOT 0004 A002 0.355 0.155 0.0
3-B1 811333 HOT 0003 A002 O.J19 0.156 0.0
3-B1 811334 HOT 000<« A002 0.329 0.153 0.0
3-B1 B11335 HOT DOU3 A002 0.268 0.16b 0.0
J-81 B11336 HOT 0004 A002 0.268 0.165 0.0
J-81 811380 HOT D004 A002 0.25** 0. b'f 0.0
3-B1 8113*9 HOT 0003 AU02 0.252 0. 70 0.0
J-bl 811591 HOT 0003 A002 0.230 0. 71 0.0
3-81 B11592 HOT OOOrt A002 0.230 0. 71 0.0
.99
.41
.'.2
.52
.50
.55
.56
.00
.00
3-81 811593 HOT 0003 A002 0.257 0. 6V 0.0 0.93
13-81 811594 HOT 000<» A002 0.247 0.166 0.0 0.91
0.17
0.16
0.09
0.09
0.32
0.32
0.23
0.23
0.36
0.35
0.51
0.52
0.34
0.34
0.19
0.18
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
.13 0.06
.13 O.b7
.08 O.H6
.07 0.05
.20 0.66
.20 0.66
.29 0.91
.30 0.91
.23 0.08
.22 0.87
.IB 0.07
. 18 0.87
.22 0.90
.22 0.90
.21 0.91
.22 0.90
(ALL G/MI)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
522.
522.
521.
527.
535.
536.
523.
525.
516.
512.
516.
519.
509.
510.
521.
525.
560.
569.
565.
567.
5<»9.
5<*9.
5<-6.
5'«6.
5M.
532.
5<*&.
551.
555.
561.
550.
547.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
16.9
16.9
17.0
16.8
16.4
16.4
16. V
16.8
17.1
17.2
17.1
17.0
17.3
17. J
16.9
16. B
U
15.6
15.6
15.7
15.6
16.1
16.1
16.2
16.2
16.4
16.6
16.1
16.1
16.0
15. B
16.1
16.2
(MPG1--
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
->l
MEAN
STANDARD OEV.
C.V.%
0.246 0.164 0.0 1.29 0.27
0.075 0.006 0.0 0.39 0.13
30.3 3.7 0.0 30.5 47.5
0.0 1.19 0.08-0.0 521. 553.
0.0 0.06 0.02 0.0 8. 11.
0.0 5.4 2.4 0.0 1.5 1.9
0. 16.9 16.0 0.0
0. 0.3 0.3 0.0
0.0 1.6 1.8 0.0
C.V.* IS THE COFKF1C1ENT OF VAUI AT I ON. <5TO. OEV./.iE«N MOO).
OIFF. % IS THE OIFFEHtNCE OF THE MEANS BETWEEN THE MFH AND EPA LAB. (MFR-EPA/EPA "100).
NOTE" THft COMMENTS PERTINENT TO THESE TESTS AHE LOCATED IN THE LAST TABLE1 OF THIS APPENDIX.
D003 '= Probe 2
D004 = Probe 1
-------
LAR CORRELATION SUMMARY - COMMENTS
327
328
329
3JO
.131
332
333
334
336
1H9
. COUGAR HOTS
PROHE 2-CwS 23 IN CHOKE
PROBE 1-CvS 24-IN CHOKE
PHOBE 2-CvS 23-IN CHOKE
PROHE 1-CVS 24-OUT OF CHOKE
PROBE 2-C-/S 23 IN CHOKE
PROBE 1-CVS 24 IN CHOKE
PP04E 2-CvS 23-lM CHOKE
PWOt'E 1-CVS 24 -OUT OF CHOKE
PROBE 2-CVS 23,-OUT OF CHOKE
PROBE 1-CVS 24-IN CHOKE
PROPE 1-CvS 2<>-lN CHOKE
PROME 2-CVS 23-OUT OF CHOKE
PROBE2-CVS 23C - IN* CHOKE
PROBE 1-CVS2««C- OUT OF CHOKE.
PPOBE 2 C-/S 23C -IN CHOKE
PROHE 1 CVS 2^»C-OUT OF CHOKE
VIN
INERTIA WT 'tSOO ACTUAL HP 13.Q
4500 IBS/13.0 ACT.
4500/13.0 ACT.
1 14.13 2 14.10 3 14.25
1 13.57 2 13.78 3 13.B7
1 13.57 2 13.78 3 13.87
1 14.03 2 13.70 3 13.99
1 14.03 2 13.70 3 13.99
1 13.60 2 13.91 3 14.09
1 13.60 2 13.91 3 14.09
1ST BAG SHOOK FOR STRATIFICATION
1ST BAG SHOOK FOR STRATIFICATION
-------
LAI} CORRELATION SUMMARY - TEST DATA
PROCESSEDI NOV 19. 1981
EPA
VtHt COUGAR HFKTS
VINI 106T004
INEHTIA WTI A500 ACTUAL HP I 13.0
.IE TESTNO TYPE HC CO NO* C02 FL DRIVER DYNO DOOM IHP BARO HUM NXFC OBL HSL TLOSS _S_EgUEN£E
)<«-Bl 811430-
I'.-Hl 01 (439-
|J-Hl 811444-
!3-rt| OH445-
16-B1 8)1606-
16-81 01)607-
)4-fll 81 1440-
J4-81 0114/.1-
>4-Bl 811442-
}<»-81 811443-
16-81 811446-
16-81 81)447-
16-81 B 1 1 4i»8-
16-81 811450-
HFFT 0.079
HFET 0.0 f8
HFLT 0.067
HFKT 0.065
HFET 0.065
HFKT 0.07?
HFFT 0.077
HFfLT 0.077
HFtT 0.077
HFFT 0.066
HFKT 0.066
HFtT 0..067
HFKT 0.067
16-BJ 811605-1 HFFT 0.067
O.OB
0.0(1
0.05
0.02
0.02
0;12
0.12
0.16
".1.5
0.06
0.05
0.0~6
0.06
0 . 07 "
0.07
f *- tit
.54 3d3. 23.1 2211H 0004 72U3.0 10.8 29.25 49.32 0.09 0-
.53 379. 23.4 22118 0003 721)3.0 10.8 29.25 49.32 0,89
,57 375. 23.6 22118 0003 7447.0 10,8 29.34 42.73 0,87
.47 378. 23.5 34704 (,)004 7540.0 9.7 20.78 58.89 0.93
.46 377. 23,5 34704 0003 7540.0 9.7 28.78 50,89 0,93
.52 372. 23.8 22129 0004 7306,0 10.8 29.26 40.08 0.89 '
.54 381. 23.2 £2129 0003 7306.0 10.8 29,26 48.08 0.89
.54 JH. 23.9 22118 0004 7329.0 10.0 29.25 51.62 0.90
..54 3.7L, &J.9 E_2JLLB (3.0.03 7.3 2_9_,_0_JLQ.,_Q 2JL...2.S 5.L..W O..JLO
.49 380. 23.3 34?U4 0004 7474.0 V.7 28.78 3^.47 0.06
.49 382. 23.2 347H4 0003 7474,0 9.7 28.78 39,47 0.06
.46 3b3. 24.4 347H4 Q00<» 7497,0 9.? 20.78 56.40 0.92
.47 371. 23.9 34784 0003 7497.0 9.7 28.76 56.40 0.92
.47 374. 23.7 34784 0003 7519.0 9.7 28.70 55.21 0.91
/LB)
8
2
3
5
6
7
I < (GRAMS)--->|
O
O
MFAN
STANDARD DE.V.
C.V.T,
D003 = Probe 2
D004 = Probe 1
0.071 O.P8 1.51 375. 23.6
.0056 0.04) .039 !>. 0.3
7.9 53.0 2.6 1.4 1.4
29.03 50.21 0.90
0.265 6.505 .024
0.9 13.0 2.7
U)
O
Test
\v\c
*VvoU
t
-------
LAfl CORRELATION SUMMARY - COMMENTS
COUGAR HFETS VIN 106TOH4 INERTIA WT 45QO ACTUAL HP 13.Q
43H PHOBE 1-CVS 24 TEST WOT 4500 POUNDS ACHP 13.0 IMP 10
.« 1 14.42 2 14.49 3 14,55
439 PWOHE 2-CVS 23 TEST WOT 4500 POUNDS ACHP 13.0 IMP
10. H I 14.42 2 14.49 3 14.55
44<» PWOBE i-cvs 24-iN CHOKE ACTUAL TEST WEIGHT » 4500 ACHP * 13.0
IHP 2 10.R .
445 PWOHE 2-CvS 23-1N CHOKE ACTUAL TEST WEIGHT = 4500 ACHP =13.0
I HP = 10.H
*,06 PHOBE 1 CVS 24C IN CHOKE AVE. CVS TEMP.- 200 TO 225 F C.D, 1 !«.<« 2 U.50 3 lfc.56
hQ7 PWOBE 2 CVS 23C IN CHOKE C.O. 1 1«».^B 2 1<>.58 3 1<».S6
'.'O PMOHE 1-CvS 2^-lN CHOKE 1 1^.55 2 14.57 3 14.61
ACTUAL WEIGHT- 4500 ACHP=13.0 1HP=10,0
«41 PROyE 2-CVS 23-OUT OF CHOKE 1 14.55 2 14.57 3 14.61
ACTUAL rfEIGHT-4500 ACHP=13.0 1HP=10.8
442 PROBE 1-CvS 24 ACTUAL WEIGHT 4500 ACHP * 13.0 IHP «
in.8 ' OC 1 14.37 2 14.52 3 14.50
443 PROBE 2-CVS 23 ACTUAL WEIGHT -4500 ACHP = 13.0 IHP =
10.0 OC 1 14.37 2 14.52 3 14.50
446 PHOBE 1-CVS 24 IN CHOKE C.O. 1 14.16, 2 14.in 3 14.19
447 PROHE 2-CVS 23 OUT OF CHOKE 14.16 14.1H 14.19
448 PROBE 1-CVS 24 IN 'CHOKE C.O. 1 14.43 2 14.52 3 14,47
«.SO PROBE 2-CVS 23 (TREAT AS AN. ODD TEST NUMBER) OUT OF CHOKE C.D. 1 14.43 2 14.52 3 14.47
604 PPOUE 1-CVS24C OUT OF CHOKE C.D. 1 14.4» 2 14.56 3 14.55
1*05 PROHE 2 CV'S-i!3C IN CHOKE C.O. 1 14.4H 2 14.56 3 14.55
-------
LAB CORHELATION SUMMARY - TEST DATA
PHOCESSEDI DEC It 1981
EPA
TE
9-81
9-81
-V-81
:0-B1
)0-81
(0-81
lO-OI
lO-Bl
TESTNO
811349
8 1 1 350
8 1 I 351
811352
ttllJbJ
B11354
811355
811356
811357
811358
81 1359
811360
TYPE
HOT
HOT
HC
0.350
0 .350
Hnf 0.559
HOT 0.561
'"H-iT
HIT
H'lT
HOT
nor
HOT
HOT
HOT
0.57U
0 .565
0.332
0.331
0.319
0.317
0.4H3
0 .482
VtHi
CU
13.90
13.91
21.07
21.10
71.81
21.71
10.11
10i02
11.00
10.91
16. 2i
16.11
ESC OUT HOTS
NOX CU2
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
MI)
09 345.
09 346.
07~3J5TT
07 336.
00" JJ3.
07 332,
14 J60.
15 350.
13 3b2.
13 361.
li 358.
11 356.
FE DH1VEW
24.1 34783
24.0 34783
24.0 34783
23.9 34783
24.0 34VH3
24.1 34703
23.5 221 18
23.J_22U.8
23.3 22118
23.4 22118
23.0 2211B
23.2 22118
(MHO)
VIM! 202-1. 6-F-076
DYNO
0003
0004
0003
0004
0003
0004
0003
0004,
D003
0004
0003
0004
DOOM
7667.1
7667. 1
7681 .5
76B1 .5
7695.1
7695.1
7712.0
_LLl.2.,.XL
7731.0
7731.0
7742.0
7742.0
I HP BARO
4.b 29.30
4.6 29.30
4.6 29.30
4.6 29.30
4.6 29.31
4,6 29.31
4.6 29.40
4.6 29.40
4.6 29.34
4.6 29.34
4.6 29.34
4.6 29.34
(IN-HG)
INERTIA WT! 2500 ACTUAL HPI 6.0
HUM NXFC DBL HSL TLUSS
55.06 0.91
55.06 0.91
54.88 0.91
54.88 0.91
5^.67 0.91
54.67 0.91
54.85 0.91
54.85 0.91
55.84 0.92
55.84 0.92
57.20 0.92
57.20 0.92
(GRAINS X (GRAMS) >l
/LB)
MEAN
STANDARD DEV.
C.V.4
D003 = Probe 2
D004 = Probe 1
0.435 15.65 0.10 349. 23.7
. 1 104 4.737 .029 12. 0.4
25.4 30.3 28.1 3.4 1.6
2V. 33 55.42 0.92
0.0-Hl HI 351
V-H1 HI 352
">-ti\ HI 353
"'-111 81 354
iD-01 81 355
;0-81 HI 356
10-81 81 357
10-81 61 358
iO-Bl 81 359
iQ-Bl 81 360
HOT
HOT
HOT
HOT
HOT
HOT
HOT
HOT
HOT
HOT
HOT
HOT
0003
0004
DOOJ
1)004
D003
0004
OOOJ
0004
DOOJ
0004
DOOJ
0004
A002
A002
A002
A002
ft002
A002
A002
A002
A002
A002
A002
0.512
0.512
0.625
0.526
0.560
0.558
0.502
0.7<*8
0.742
0.201 0.0
0.201 0.0
0.49^ 0.0
0.502 0.0
0.606 0.0
0.600 0.0
0.121 0.0
0.121 0.0
0..151 0.0
0.151 0.0
0.240 0.0
0.24J 0.0
c
15
15
19
19
18
18
13
13
13
13
20
19
0
.M4
.M.3
.65
.72
.20
.14
.35
.23
.27
.16
.12
.89
f
12.
12.
22.
22.
25.
25.
7.
7.
8.
8.
12.
12.
11
15
39
37
15
01
12
05
92
84
6<>
64
3
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
(ALL
0
0
0
0
0
0
0
0
0
0
0
0
NO
0.
0.
o.
0.
0.
o.
0.
0.
0.
0.
0.
0.
G/MI
X
11
1 1
10
10
11
10
15
17
16
16
16
15
I
0
0
0
0
0
0
0
0
0
0
0
0
2
.06
.06
.04
,04
.05
.04
. 13
.13
.11
.11
.06
.06
0
0
0
0
0
0
0
0
0
0
0
0
3
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
C02
305.
305.
299.
301.
299.
297.
328.
328.
327.
328.
322.
320.
FE
381.
384,
368.
369.
36-».
364.
389.
386.
395.
392.
390.
389.
MEAN
STANDARD DEV.
C.V. I
D003 = Probe 2
DOOA = Probe 1
0.578 0.303 0.0 16.70 14.70
0.089 0,190 0.0 2.91 7.00
15.4 62.8 0.0 17.4 47.6
0.0 0.13 0.07 0.0
0.0 0.03 0.04 0.3
0.0 21.7 47.6 0.0
313. 381.
13. 11.
4.2 3.0
0
0
0
0
0
0
0
0
0
0
0
0
*
t
*
26
26
26
26
26
27
25
25
25
25
24
25
*
f
r
8
7
6
9
1
3
3
3
it
9
1
22
22
21
21
21
21
22
22
21
21
21
21
*
*
»
»
1
0
9
8
9
9
2
3
7
8
6
7
0.
0.
0.
0.
0.
0.
0.
0.
0,
0.
0.
0.
0
0
0
0
0
0
0
0
0
0
0
0
|< (MPG) >l
.0
0
0.
0
26
0
3
0
8
3
21
0
1
9
2
0
0.
0.
0.
0
0
0
to
o
o
to
33
o
H
o
H
W
CO
H
CO
-------
LAO CORRELATION SUMMARY - COMMENTS
ESCORT HOTS V1N 2G2-J,6-F-OId INERTIA- WT 2500 ACTUAL HP 6.0
349 PROBE 2-CVS 23-1N CHOKE E.O.T. 5 SECS. AFTER 24C
350 PROHE 1-CvS 24- IN CHOKE 1 14.50 2 14.61 3 14.60
351 PROHE 2-CVS 23-IM CHOKE
352 PROHE 1-CvS 2
-------
LAd CORRELATION SUMMARY - TEST DATA
PHOCESSEOI DEC It 19B1
: EPA
VEH! ESCORT HWFET5
VIM! 202-1.6-F-076
INERTIA WTI 2500 ACTUAL HP I 6.0
«TE TESTNO TYPE HC co NO* coa FE DRIVER OYNO DOOM IHP BARO MUM NXFC OBL HSL TLOSS
?rf-81
J2-B1
/8-B1
24-81
29-81
P9-81
?9-81
29-81
811363-1
B11364-1
81 1365-1
81 1366-1
81136/-1
81136^-1"
B11370-1
811371-1
811372-1
81 1386-1
811387-1
HFFT
HFK T
HFF;T
HFET
HFFT
HFK.T
HFF.T
HFKT
HFFT
HFKT
HFET
0.094
0.095
0. 126
0.126
O.OB2
O.OM2
6,07V
0 . 0 B 1
0.071
0,075
0.072
0.071
4.1 1
4^69
3.80
2.97
2.76
2.72
0.12
0. 12
0.13
0.13
0.15
0. 15
0.21
0.21
0.21
0.21
2.02 0. IV
2 . 8 1 0.19
237.
236.
239.
237.
237.
237.
239.
238.
240.
236.
23B.
236.
36.4
36.5
35.9
36,2
36.4
36.3
36.5
36.2
36.8
36.6
36.8
3009B
3089H
3089b
30(198
iTZfTT
17282
172*2
17282
34783
1
0003
0004
0003
0003
0003
0004
0003
0004
0003
751 1.0
751 I .0
7522.9
7555.1
758272
75H2.2
7610.3
7610.3
7636.5
7636.5
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
4.6
29.30
?9.30
2V. 2B
29.29
29.29
29.35
29.35
29.35
29.35
29.34
29.34
(IN-HG)
47.95 0.89
47.95 0,89
53.70 0.91
5J)j_70 Q,9L_
53.67 0.9).
53.67 0.91
52.20 0.90
52.20 0.90
57.50 0.92
57.50 0.92
54.60 0.91
54.60 0.91
(GRAINS
/LB)
t
9
§
(<-
MEAN
STANDARD DF.V.
C.V.*
D003 = Probe 2
D004 = Probe 1
O.OHB 3.53 0.17 238. 36.4
.0195 0.764 .038 1. 0.3
22.2 21.7 22.8 0.6 0.7
29.32 53.27 0.91
0.058 2.999 .012
0.2 5.6 1.3
prcAoe
|< (GRAMS! >l
Cn
O
O
-------
LAP co'»nf.LAT ION SUMMARY - COMMENTS
ESCORT HWFETS VIM 2G2-1.6-F-076 INEHTlA-wT 2bOO ACTUAL HP 6.0
PWOHE 2-C^S 23-1N CHOKE C.D.15.20 ,15,16,15.Ob
PROHE 1-CvS 24-l'J CHUKE C.D. 15.20.15.16,15.06
PROHE 2-CvS 23 C.0.15.2V,15.21, 15.12
PROHE 1-CvS 2<» C.O. 15.2V,15.21 ,15.12
PROBE i>-Cv5 23-lN CHOKE
PROHE 1-CVS 2<»-UUT OF CHOKE CO 1 J5.34 2 15.37 3 15.22
PROHE 2-CVS 2J-OUT OF CHOKE
PROHE 1-CVS 2<»-lN CHOKE 1 15.28 2 15.33 3 15.27
PROHE ^-C'/S 23 OC'S. 1 15.30 2 15.40 3 15.36
PROHE 1-CVS 2<» OC'S. 1 15.30 2 15.40 3 15.36
PROHE 1-CVS 24-OUT OF CHOKE 1 15.35 2 15.35 3 15.28
PWOHE 2-CvS 23-lN CHOKE OC'S. 1 15.35 2 15.35 3 15.28
-------
20x20 TO 1NC1I
SEQUENTIAL ABSOLUTE FUEL ECONOMY - 4500 Ib.
ry
5 6
SEOUENCE
3 A 5 6
SEQUENCE
-------
HER 20x20 TO INCH
SEQUENTIAL PAIRED DIFFERENCES - 4500 Ib.
-------
HEE 20x20 TO INCH
SEQUENTIAL, ABSOLUTE FUEL ECONOMY - 2500 Ib.
SEQUENCE
SEQUENCE '
-------
J\fF. 20x20 TO INCH
SEQUENTIAL PAIRED DIFFERENCES '- 2500 Ib.
111
I
>0t
s
:AH₯
v<
I
p t:
to;
ill
"
If
in
I i!
-------
CVS PROBE STUDY
Test Plan 2
Fuel Economy
.90 Confidence Intervals
(Student1
VEHICLE
2500 Ib. 6.0 AltP
Mean MPG
Absolute AMPG-interval (min, max)
A% - Interval (min , max)
% confidence that a difference
( mai exist
| 4500 Ib, 13.0 AHP
' Mean MPG
Absolute AMPG - int. (min, max)
1
A% - interval (min, max)
% confidence that
-------
ATTACHMENT H
Theoretical Analysis
Sonic velocity is defined as the maximum obtainable velocity of gas that can
be achieved regardless of the outlet pressure depression. The term "critical"
or "choked flow" means that sonic velocity exists at the minimum area or
throat section of the venturi. This means that when "choked" or "critical"
flow conditions are reached the venturi reaches a maximum flow in actual cubic
feet per minute (ACFM).. The flow in ACFM is then independent of flow
variations due to venturi outlet pressure or other variations. Thus, a CFV
provides a constant volumetric metering element. The basic flow equation for
a CFV is derived in CVS technical note //I and 3 by Warren F. Kaufman for
Ford/Philco October 6, 1971.
Critical Flow Venturi:
Q = Volumetric flow rate (ft^/sec)
A = CFV effective metering area (ft^)
g = Gravitational constant (32-2 ft/sec^)
"R = Universal gas constant (1545 ft-lb/°R mol)
Mw = Molecular weight of gas (Ib-mol)
To = Qas total temperature (°R)
K = Gas Specific heat ratio (dimensionless)
M = Mach No. at inlet to venturi = v/c (dimensionless)
V = Gas velocity - (ft/sec)_
C = Velocity of sound =^CglT/Mw' (ft/sec)
T = Gas static temperature (°R)
The flow rate equation does not contain inlet or venturi differential
pressures as factors.
The bracketed term in the preceeding equation is a function of the inlet Mach
number which in turn is a function of the ratio of the venturi inlet section
area (Aj) to throat area (A*):
l 1
A* M
k+1
k+1
(2)
M = Mach no. at inlet to venturi (dimensionless)
K = Gas specific heat ratio (dimensionless)
-------
A typical EPA CVS main venturi inlet diameter is approximately 3.875" and the
throat diameter is approximately 1.3". The ratio of specific heats (K) for
air and for nitrogen (largest mol fraction in the exhaust gas) are constant
and equal to 1.40 for the temperature range of interest. Equation (2)
reduces to:
M = 0.064
A typical EPA CVS sample probe venturi inlet diameter is approximately 0.185"
and throat diameter approximately 0.035" yields:
M = 0.021
Substitution of either of these values for M into equation (1) results in the
bracketed term being essentially equal to unity. Equation (1) thus reduces to:
(3)
By definition g, and R are constants. For the temperature range of interest
specific heat ratio (K) and molecular weight (My) are essentially constant.
Finally, the area of each venturi remain constant.
Formula (3) then reduces to:
Qsample ~ ^sample ,J1 sample anc^ Qmain ~ Cmain
Or actual flow in the sample probe and main Venturis are proportional to'the
square root of the absolute temperature of the gas mixture. The ratio of the
flow equations for the main and sample Venturis will be:
Qsample ^sample ./^sample
~ ^main ^
The sample probe is physically located at the main venturi inlet, consequently:
^sample = ^main
Q
samPle = Constant
Qmain
or the two Venturis being in choked flow guarantees a constantly proportional
sample.
------- |