EPA-AA-IMS/80-5-C
TECHNICAL REPORT
MARCH 1981
RECOMMENDED SPECIFICATIONS
FOR
EMISSION INSPECTION ANALYZERS:
CHANGE NOTICE NUMBER 1
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EPA-AA-IMS/80-5-C
Technical Report
March 1981
Recommended Specifications
For
Emission Inspection Analyzers:
Change Notice Number 1
By
William B. Clemmens
Notice
This Report does not necessarily represent final EPA decisions or positions.
It is intended to present technical analysis of the issue using data which are
currently available. The purpose in the release of such reports is to facil-
itate the exchange of technical information and to inform the public of
technical developments which may form the basis for a final EPA decision,
position or regulatory action.
NOTE: This report is the third in a series of reports. Report EPA-AA-IMS/
80-5-A contains background, technical discussions, and policy information on
Inspection Analyzers. Report EPA-AA-IMS/80-5-B provides the Recommended
Technical Specifications for inspection analyzers. This report (EPA-AA-IMS/
80-5-C) provides modifications to those specifications. The reports are
available separately.
Inspection and Maintenance Staff
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
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TABLE OF CONTENTS
I. Forward 3
II. Modified Sections in Chapter VI
A. Section D: Definitions and Abbreviations 5
III. Modified Sections in Chapter VII
A. Recommended Qualification Program 6
B. Section A. Gases 8
C. Section B. Gas Cylinders 9
D. Section D. Design Requirements 10
E. Section E. Analyzer Performance Specifications 13
F. Section F. Sample System Performance Specifications 16
G. Section G. Operating Environment 18
H. Section H. Fail-Safe Features 19
IV. Modified Sections in Chapter VIII
A. Introduction to Chapter VIII 20
B. Section A. Automatic Zero/Span Check 21
C. Section B. Automatic Leak Check 22
D. Section E. Dual Tailpipes 23
E. Section H. Vehicle Diagnosis 24
F. Section I. Anti-Tampering 25
V. Modified Sections in Chapter IX
A. Section B. 26
B. Section C. Anti-Dilution 27
C. Section D. Loaded Mode Kit 28
VI. Modified Sections in Chapter XI
A. Introduction to Chapter XI 29
B. Specific Test Procedure Changes 31
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I. FORWARD
In September of 1980, EPA published two technical reports dealing with I/M
inspection analyzers. The first report, "Analysis of the Inspection Analyzer"
(EPA-AA-IMS/80-5-A), discussed background information on the analyzers them-
selves, provided a brief comparison of analyzers specifications, listed some
sample cost calculations, and indicated a few policy implications. The second
report, "Recommended Specifications for Emission Inspection Analyzers"
(EPA-AA-IMS/80-5-B) detailed the I/M Staff's findings on analyzer specifica-
tions for both a manually operated inspection analyzer and a computer operated
inspection analyzer.
Once EPA's analyzer recommendations were formalized, analyzer manufactur-
ers could then justify the time and expense of initiating engineering design
studies targeted towards building an EPA analyzer. From these studies came
several requests for better interpretation or clarification- of certain
portions of the EPA specifications. In other cases, the specifications
stimulated the manufacturers to come up with "better mouse trap" approaches
that met the intent of the specifications, but might not have passed a
bureaucratic interpretation of the specifications. In still other areas, the
manufacturers offered new evidence or more convincing arguments that a
relaxation of the specifications in a few specific instances was necessary
from a technical perspective in relation to the targeted market and cost.
As discussed in the "Recommended Specifications ..." (80-5-B), the
technical report format used by the Office of Mobile Source Air Pollution
Control (OMSAPC) has no formal mechanism for instituting a change to previous
reports other than publishing a new report. This report (80-5-C) constitutes
such a change-notice to EPA-AA-IMS/80-5-B, and when published, officially
superceeds those portions of 80-5-B.
This report does not recompile the original specification report
(80-5-B). With only a few exceptions, the format of this report (80-5-C) is
laid out in two sequences which are used interchangeably. In all cases, the
chapter and section of 80-5-B are identified. As appropriate, the subsection
and item are identified followed by a descriptive sequence of either:
•
a) Previous Concept:
b) New Concept:
c) Reason for Change:
d) New Wording:
or
a) Previous Wording:
b) New Wording:
c) Reason for Change:
In most cases, the format keys around the word "item", and the new wording is
a direct replacement for the previous wording under that "item" (e.g. Section
D, Subsection 3.d), Item i)2); or Section I, Item, Subsection 2.). Following
the "item" heading is the page number location (in parenthesis) of that
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heading in report 80-5-B. The few cases that are not in this specific format
are reasonably self-evident.
The changes discussed in this report will not adversely affect analyzer
lead-time, the number of manufacturers interested in developing an EPA
analyzer, or state implementation schedules. In fact if anything, these
changes (relative to 80-5-B report) should decrease the lead-time and increase
the number of manufacturers interested in producing an EPA inspection
analyzer. Therefore, the publication of these changes should not cause any
disruption in current state implementation schedules or plans.
EPA wishes to acknowledge the valuable comments and considerable efforts
put forth by the Equipment and Tool Institute in supporting the development of
this report.
As always, the I/M staff at EPA's Ann Arbor Facility is available to
provide additional assistance and information as necessary. You may contact
Tom Cackette, Donald White, or Bill Clemmens at (313) 668-4367.
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II. Modified Sections in Chapter VI
A. Section D. Defintions and Abbreviations (p. 13)
1. New Definitions
a) Indicator, Lights: Indicator lights as used in his document mean
any means used to effectively communicate with the operator (e.g.,
lights, computer prompts, etc.).
b) Output pevicg: For the purpose of this document, output device
means any device that displays or prints emission values. If an
output device displays information other than the emission values
(e.g., CRT diagnostic display), only the emission value portion of
the multiple display is considered the output device.
c) Switches; Switches as used in this document are a generic term
meaning any process used to control analyzer functions (e.g.,
switches, buttons, alpha-numeric keyboard, etc.).
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6
III. Modified Section in Chapter VII
A. Recommended Qualification Program (p. 17)
1. Item III. Subsequent Production QA/QC (p. 17)
a) Previous Concept: Required full accredidation testing on all
aspects every three years after initial certification.
b) New Concept: Requires re-certification testing only -on specified
key parameters every three years after initial certification.
c) Reason for Change: The change to recertifying key parameters is
implemented to reduce the re-certification testing costs.
d) New Wording; The accreditation may be re-certified for a three
year period at any time by passing selected evaluation tests on two
of three units selected randomly from a production run of 20. The
selected tests will include the following:
1. Testing of all specifications in Section E of Chapter VII
(Analyzer Performance Specifications).
2. Testing of all specifications in Section F of Chapter VII
(Sample Systems Performance Specifications).
3. Testing the following at the high temperature specifications
of test procedure G.I. in Chapter VI (Operating Environmental
Test Procedures).
a. Analyzer Calibration Curve
b. Pressure and Temperature Compensation (if used)
c. Analyzer zero and span drift
d. Analyzer Response Time
4. Testing the following at the low temperature specification of
test procedure G.I. in Chapter XI (Operating Environment Test
Procedures)
d. System Warm-up
2. Item IV. QA/QC Testing Criteria (p. 18)
a) Previous Concept: Repairs due to random failures during evaluation
testing were allowed on pre-production units only. Justification
required.
b) New Concept; Allow repair of random failure during accredidation
and re-certification testing as long as justified by engineering
report.
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c) Reason for Change; To reduce the cost of accredidation and
re-certification testing.
d) New Wording: Random failures must have sufficient documentation
(i.e., published report available to regulatory bodies) to justify
why the failure can be attributed as a random failure and not minor
design failure. Random failures may be repaired on all units. A
condition to allow the repair of production analyzers is the develop-
ment of a plan (where necessary) to prevent the specific type of
failure in future production units. After repairs, those tests that
might be affected by the repairs should be rerun.
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Spec: A.2.-3.
B. Section A. Gases (p. 19)
1. Subsection 2. Item d) zero gas
a) Previous Wording: Zero gas may be
i) bottled air,
ii) chemically purified room air such as with an activated
charcoal trap on the anlysis system, or
iii) catalytically purified room air.
b) New Wording: Zero gas may be air or N£. The impurities in
bottled zero gas must be analyzed at less than the maximum allowable
level. Ambient room air may be used for routine spanning of
inspection equipment.
c) Reason for Change: To clarify original intent between in-use zero
gas and audit gases (see sub-section 3).
2. Subsection 3. Recommended number of gases: b) for in-use systems. Item
ii) (p. 20).
a) Previous Wording: purified room air zero gas
b) New Wording; zer.o gas may be drawn from the ambient air
(room-air). It is preferred that the pick-up of ambient zero air is
as high off the floor as practical. Suggested accessory items (not
required) are chemical or catalytic devices to purify the ambient
air, or a zero-air port that would allow use of ambient zero air
drawn from outside the test cell or building.
c) Reason for Change: To clarify original intent to not require
bottled zero gas on in-use analyzers.
3. Subsection 3. Recommended number of gases c) for periodic check ...
Item iii) (p. 20).
a) Previous Wording: bottled zero gas
b) New Wording; bottled zero gas (because the audit check will use
bottle zero gas and the in-use system will use ambient room air, a
background emission calculation must be used during the audit check.)
c) Reason for Change: In allowing ambient room air to be used as zero
gas for in-use systems, there can be an offset in the gain setting of
the span control if there is a significant level of background
emissions. Background emission levels can vary substantially from
location to location. In order to evaluate the operation of the
machine, background levels should be measured during the audit check.
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Spec: B.I.
C. Section B. Gas Cylinders (p^ 21)
1. Subsection1. Item d)
a) Previous Wording: Disposable cylinders may not be used
b) New Wording: Disposable cylinders are generally not desireable in
the context of gas blending, gas stability, and gas traceability.
Also, the quantity of gas in the disposables is generally quite small
(approximately 7-8 cubic feet) compared to the refillable bottles
(160 cubic feet). The small size of the disposable bottles requires
more frequent replacement in the field. The disposables are,
however, convenient to handle and ship. Therefore, disposable
cylinders may be used .for in-use systems (not audit) provided that
the suppliers of the disposable bottles include the following quality
control measures.
i) The inside surfaces of the cylinder conform with the NBS CRM
or SRM procedures for preparation, cleanliness, trace materials,
composition, coatings, etc. for the gas composition and con-
centrations used.
ii) The cylinder valve shall conform with NBS CRM or SRM
procedures for preparation, packing materials, cleanliness,
composition, etc. for the gas composition and concentrations
used.
iii) The stability over the normal usage time of the gas
concentraton shall be periodically checked from random
production lots by the NBS CRM procedure.
c) Reason for_.Change:. To allow the use of disposable cylinders.
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10
Spec: D.3.d) & e)
and
D.7.b)
D. Section D. Design Requirements
!• Subsection 3. Sample System d) Water Trap, Item i) 2) (p. 24)
a) Previous Concept; Electronic compensation (based on pressure and
temperature) of the water in the sample was allowed.
b) New Concept; The previous concept assumed that the sample leaving
the water trap was saturated. This may not be the case for all
systems under all conditions. Therefore, the wording for Item 2. is
deleted, and new wording is substituted.
c) New Wording;
Option 2; Other techniques to either remove the water from the
sample (e.g. permapure @, etc.) or correct for the water content
(electronic dew point, pressure, etc.) may be used if they can
be demonstrated to be equivalent to Option 1.
2. Subsection 3. Sample System e) Particulate Filter, Item vi) (p. 24)
a) Previous Concept: The particulate filter before the optical bench
was required to be 5 micron or less.
b) New Concept; The particulate filter before the optical bench is
preferred to be 5 micron or less.
c) Reason for Change; To allow more flexibility in system design.
d) New Wording; It is preferred that the filter element and filter
system shall be designed to prevent particulates larger in size than
5 microns from entering the sample cell of the analyzer. The
location of this suggested optical bench filter (5 micron) is up to
the manufacturer and may be on the pressure or vacuum side of the
system. If this filter only filters sample gases passing through the
analyzer, the manufacturer may elect to have an additional filter
prior to the system pump(s). The particulate size of this optional
filter is at the discretion of the manufacturer. Verification of
filter particulate size removal may be determined by the filter
manufacturer using standardized ASTM or Filter Industry procedures.
3. Subsection 7. Analyzer Spanning System, Item b) (p. 26)
a) Previous Wording:
Recommended Gas Spanning Frequency: It is recommended that the
analyzer be gas spanned after:
i) every "power on" and warm-up sequence, and
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11
Spec: D.7.e) & h)
ii) every 4 hours of "power-on" condition when testing.
b) New Wording;
Recommended Gas Spanning Frequency; It is recommended that the
analyzer be gas spanned after:
i) every "power on" and warm-up sequence, and
ii) every 4 hours of "power-on" condition when testing.
iii) If this gas spanning frequency is used, the analyzer is not
required to have any temperature or barometric correction.
c) Reason for Change; To clarify original intent.
4. Subsection 7. Analyzer Spanning System, Item e) (p. 26)
a) Previous Wording; Last sentence in subparagraph e) ... The audit
port should interconnect the span system downstream of the span/zero
switching valve.
b) New Wording; Delete the last sentence in subparagraph e).
c) Reason for Change; The sentence was included to allow for leak
checking the span/zero switching valve during the audit. There are
other ways to check this valve more cost effectively.
5. Subsection 7. Analyzer Spanning System, Item h) (p. 26)
a) Previous Concept; Subparagraph h) required operator tracking of
the gain setting to identify analyzer problems or dirty sample cells.
b) New Concept: Replaces operator tracking by requiring the analyzer
manufacturers to limit the overall gain adjustment such that gain
cannot be turned up to the point where the signal-to-noise ratio
prevents the analyzer from meeting the calibration curve and drift
requirements.
c) Reason for Change; To allow the manufacturers more flexibility in
the analyzer design.
d) New Wording; (Delete the previous wording for subparagraph h) and
substitute the following). The overall analyzer span gain-control
shall be limited such that when compensating for analyzer degradation
the operator runs out of gain adjustment before the signal-to-noise
ratio of the analyzer prevents the analyzer from complying with the
calibration curve and drift requirements in Section E.
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Spec: D.7.1)
6. Subsection 7. Analyzer Spanning System, 1) Span Cylinders, Item i)
(p. 27).
a) Previous Concept: Requires the use of and supporting equipment for
200 cubic foot gas cylinders.
b) New Concept: Make specifications consistent with changes in
Section B. (Gas Cylinders) that allow the possible use of disposable
cylinders.
c) Reason for Change: Consistency with other changes.
d) New Wording; For stand alone centralized inspection analyzers (a
condition determined by the State or Contractor) and all decentral-
ized analyzers, the analysis system shall include a structure for
safely securing two refillable span cylinders, or shall include an
easily utilized source for procurement of such a structure by the
owner as well as safety and operating instructions for use of the
structure. Appropriate regulator(s) and lines shall be provided for
the type of cylinder(s) used. All analyzers not utilizing a- refill-
able bottle shall prominently display a label or a sticker which
indicates that "AN OPTIONAL KIT INCLUDING A GAS REGULATOR AND HOSE IS
AVAILABLE THAT ALLOWS THE USE OF LARGER MORE ECONOMICAL GAS
CYLINDERS". The analyzer manufacturer must provide such a kit. The
manufacturer's kit shall be evaluated during the accreditation
tests. The kit shall be included in all areas where disposable
bottles of traceable span gas are not available from an accredited
source. In areas where disposable bottles are available, the
manufacturer's sales literature and presentations should at least
give equal treatment to the kit and larger bottles (compared to the
disposable bottle system). A fair comparison of captial costs,
operating costs, bottle change-out frequency, payback time, etc. is
suggested. If the system includes a C02 analyzer, regulator(s) and
lines shall be provided for one cylinder of C02 span gas.
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Spec: E.I. & 3.
E. Section E. Analyzer Performance Specifications (p. 31)
1. Subsection 1. Calibration curve uncertainty, Item a) (p. 31).
a) Previous Wording; 5% of point (i.e. true value of reading).
b) New Working; 5% of point (i.e. true value of reading) at and above
1.2% CO and 220 ppm HC. Below 1.2% CO and 220 ppm, the uncertainty
limits are 0.06% CO and 11 ppm HC.
c) Reason for Change; The previous calibration curve uncertainty
specification (5% of point) at low CO values was necessary due to the
possibility of newly promulgated Federal LDT and HD idle standards of
0.47% CO becoming performance warranty standards. It is now reason-
ably clear that 5% of point uncertainty at 0.5% CO is beyond the
capability of optical benches that are available or will be available
in the near future without major redesign or modifications. Although
selected units of the current designs can meet the previous specifi-
cations, the production lot of the equipment is not expected to have
the consistency to meet the previous specifications. The new
specifications are a compromise among accuracy, cost, and availabil-
ity.
2. Subsection 3. Compensation, Item b)i) (p. 31)
a) ^Previous Wording; The temperature compensation network shall
provide accurate results over the ambient temperature range specified
in Section G of this chapter as well as exhaust gas temperatures up
to 49°C (120.2°F). (Units with heated sample cells are excluded from
this requirement).
b) New Wording; The analyzer shall provide accurate results over the
ambient temperature range specified in Section G of this chapter as
well as exhaust gas temperatures (at the sample cell) up to 49°C
(120.2°F). (Units with heated sample cells are excluded from this
requirement). If the automatic temperature compensation network does
not compensate for the full range of the required temperatures, the
analyzer should revert to a 4 hour gas span check at temperatures
outside of the compensated range. If the evaluation temperatures for
Section G are outside the compensated range, the standard uncertainty
procedures (which include prior gas span at the prevailing ambient
temperatures) should be used at these temperatures. Also, if the
evaluation temperatures are outside the compensated range, additional
tests should be performed to evaluate the compensation network. The
tests should include checking the actual activation and deactivation
temperatures as well as checking the analyzer uncertainty with the
compensation network active at a temperature 2°C above the actual
activation temperature, and at a temperature 2°C below the actual
deactivation temperature (e.g. 12.8°C to 35°C (55-958F) compensation
range, test temperatures should be 14.8°C and 33°C). The actual
activation and deactivation temperatures should be +3°C of the
manufacturer's stated temperatures.
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Spec: E.7. & 8.
c) Reason for Change: The use of. a temperature compensation network
is optional at .the analyzer manufacturer's discretion. Current
compensation networks are -somewhat limited in the ability to maintain
(through electronic compensation) an accurate calibration curve over
the full temperature range required in Section G. However, over
their limited operating range (usually 55-95°F), they are reported to
perform adequately. The advantage of the compensation network is the
ability to shift from the recommended 4 hour span check to a weekly
span check. The change in the compensation specification was made in
order to utilize the benefits of lower span gas consumption exhibited
by the compensated analyzers while maintaining the required accuracy.
3. Subsection 7. Sample Cell Temperature, Item b) (p. 32).
a) Previous Concept: If the sample cell is not heated, the system
must provide temperature compensation.
b) New Concept: If the sample cell is not heated, it is preferred
that the system provide temperature compensation.
c) Reason for Change: The original concern was about changes in the
sample gas temperatures entering the optical bench. Current systems
tend to reduce the sample gas temperature. to near ambient tempera-
tures at (or near) the water trap/filter assembly(s). Fundamentally,
this practice should reduce variability of the sample gas entering
the optical bench. Another concern was the potential for the sample
gas temperature to be different from the span gas temperature. Any
difference in temperature would cause an error in the span setting
that could only be detected when sampling a vehicle. Large span
errors due to temperature differences should be able to be identified
by the correlation test (to laboratory analyzers) on vehicle exhaust
(Section I). Theoretically, then, the requirement for temperature
compensation can be eliminated, but to be on the safe side, we would
prefer (but not require) temperature compensation if the sample cell
is not heated.
d) New Wording; If the sample cell is not heated, it is preferred
that the analysis system compensates for temperature effects on the
gas (sample or span) measurement process as in Section 3.
4« Subsection 8. Interferences b) Electronic, Item v) (p. 33).
a) Previous Wording:
Line voltage and : 1.0% fs L.S.
Frequency Variation
(90-130 vA.C.)
(59-61 hz)
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Spec: E.8.
b) New Wording:
Line voltage and : 1.0% fs L.S.
Frequency Variation
1) Normal system operation at 115 vA.C. +^10%
2) Electronics to be tested between 100-130 vA.C.
3) Normal system operation at 59-61 hz
c) Reason for Changei Most manufacturers use the same source for the
sample pump. The particular sample pump used has difficulty oper-
ating at low voltages, and won't start at extremely low voltages.
The reason for the wide voltage specifications in the previous
wording was that line voltage fluctuation and location in the power
grid as well as "brown-outs" in urban areas can easily cause the true
line voltage to exceed tradition voltage specifications (115 vA.C.
+^10%). The concern was about the accuracy of the analyzer when the
voltage available for the analyzer was outside of the traditional
val-ues. Therefore, to prevent pump damage, the evaluation test will
not attempt to start the sample pump below 106 vA.C, but will test
the electronics down to 100 vA.C.
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Spec: F.I.3. & 5.
F. Section F. Sample System Performance Specifications (p. 34)
1. Item, Subsection 1. (p. 34)
a) Previous Wording: Maximum sample cell mean pressure differences
between gas spanning and sampling: 4" H20
b) New Wording: Maximum sample cell mean pressure differences -between
gas spanning and sampling: 4" 1^0 or exhibit less than a 1%
difference in the mean low-range calibra-
tion curve (see E.I.) measured through
the span port compared to the mean
low-range calibration curve measured
through the probe.
c) Re a s o n for Cha ng e; Allow the manufacturers more flexibility.
2. Item,. Subsection 3. (p. 34.)
a) Previous, Wording; Maximum sample cell mean pressure difference
between normal flow and low flow indication : 4" H20
b) New Wording: Maximum sample cell mean pressure difference between
normal flow and low flow indication: 4" H20 or exhibit less than a
1% difference in the mean
response on the low range to a
span gas measured through the
probe at normal flows compared
with the mean response on the
low range to a span gas measured
through the probe at a flow rate
corresponding to the flow rate
that activates the low flow
indication.
c) Reagpn for Change: Allow the manufacturers more flexibility.
3. Subsection .5... System. Leakage.,. Item b) (p. 34).
a) Previous Wording: The pressure side of the sample system shall be
leak free as determined by a "bubble" leak-check method (not to be
used in the field).
b) New Wording; The pressure side of the sample system shall be leak
free as determined by a "bubble" leak-check method (not to be used in
the field). The sample cell pressure shall not exceed the maximum
normal operating pressure for this check.
c) Reason for Change^ To protect the analyzer from possible damage
due to overpressure.
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Spec: F.5. & 6.
4. Subsection 5. System Leakage, Item c) (p. 34).
a) Previous Wording; The vacuum side leak-check method shall consist
of a comparison of the span gas response introduced through the span
network to the response of the same span gas introduced through the
probe and sample line. In the future with demonstrated and histori-
cal data, other leak-check techniques may be accepted or equivalent
to the gas comparison leak-check.
b) New Wording: The vacuum side leak-check method shall consist of a
comparison of the span gas response introduced through the span
network to the response of the same span gas introduced through the
probe and sample line. Other leak-check techniques may be accepted
as equivalent to the gas comparison leak-check with appropriate
comparative evaluation of the fundamental mechanisms involved, and a
demonstration of the technique. These other techniques (such as
vacuum level/time decay) shall use a 1.5% measurement error trigger
instead of the 3% measurement error trigger specified for the gas
comparison leak check.
c) Reason for Change: Provide the manufacturers more flexibility.
5. Subsection 6. HC Hang-up, Item a) (p. 35).
a) Previous Wording; The HC analyzer response to room air sampled
through the probe and sample line shall be less than 20 ppm C6 prior
to testing a vehicle or the test is void.
b) New Wording; The HC analyzer response to room air sampled through
the probe and sample line shall be less than 20 ppm C6 (as measured
by the analyzer zeroed on room air) prior to testing a vehicle or the
test is void.
c) Reason for Change: Most analyzers will set zero with room air.
The difference between room air measured from the zero port and room
air measured from the sample line will usually be adequate to
indicate the amount of hang-up for this type of testing.
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Spec: G.I.
G. Section G.. Operating. Environment (p. 36).
1. Subsectionl.b) Ambient Relative Humidity.,. Item, i) .(p.. 36).
a) Previous. Wording; Range of field operation: 0% to 100% condensing
(i.e. raining or dense fog).
b) New Wording:
Range of field operation: The analyzer shall be designed for use
inside a building or semi-protective
shelter that is vented or open to outside
ambient humidity; The analyzer shall be
designed for use in such locations when
the outside relative humidity ranges
between 0% to 100% condensing (i.e. rain-
ing or dense fog).
c) Reason for Changej To clarify intended instrument use, .and to
indicate that instrument need not be designed for submersible oper-
ation.
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Spec: H.I.
H. Section H. Fail-Safe Features
1. Subsection 1. Warm-up c) lock-out, Item i) (p. 37).
a) Previous Wording: When system power is turned on. The lock-out
shall stay on until the zero drift is stabilized. The manufacturer
must condition the lock-out on analyzer parameters, and may not use
clock time as a sole criteria to determine warm-up condition.
Verification of proper zero stabilization is determined by observing
the zero drift over a 5 minute period after the lock-out feature
deactivates. The zero drift during this 5 minute period may not
exceed one-half of the zero drift specifications in Section E. If
digital sampling of the zero level is used, the sample rate shall be
at least 10 hertz. Analog observation of zero drift is permissible.
b) New Wording; When system power is turned on. The lock-out shall
stay on until the zero drift is stabilized. The manufacturer must
condition the lock-out on analyzer parameters, and may not use clock
time as a sole criteria to determine warm-up condition. Verification.
of proper zero stabilization during the evaluation test is determined
by observing the zero drift over a 5 minute period after the lock-out
feature deactivates. The zero drift during this 5 minute period may
not exceed one-half of the zero drift specifications in Section E.
c) Reason for Change; To clarify intent and to remove test procedure
specifications to the test procedure section.
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IV. Modified Sections in Chapter VIII
A. Introduction to Chapter VIII. .(p.. 41).
1. Add Sentence: "... the word "void" prominently and/or superimposed over
the data." Alternatively, a different format for inspection form versus
repair form may be used in place of the printer interlock and void stamp,
provided that there is an easily discernable difference between the
formats and that the repair form can not be used for inspection results.
"All valid test results ..."
2. Reason for. Change: Provide more flexibility for the designer.
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B. Section A. Automatic_Zero/Span checlc (p •
1. Item^ Subsection 6. (p.^41^ 42).
a) Previous Wording: The concentrations of span gas shall be entered
via switches or other convenient means to the following resolution:
HC = XXXX ppm propane
CO = X.XX% CO
The switches or interlock that allows the entering of the span gas
values shall be in an anti-tamper box as described in this chapter.
b) New Wording: The concentrations of span gas shall be entered via
switches or other convenient means to the following resolution:
HC = XXXX ppm propane
CO = X.XX% CO
The switches or interlock that allows the entering of the span gas
values shall be in an anti-tamper box as described in this chapter.
In place of locating the span gas concentration switches in the
anti-tamper box, the analyzer manufacturer may allow user access to
those switches if the system prints the gas concentrations, as
determined by those switches, on each consumer inspection ticket.
The printed value of the span gas concentration need not be identi-
fied as long as the format allows the auditor to check the values.
To use this alternative (printing concentration values) with the
optional automatic data collection (ADC) system, the microprocessor
shall automatically enter the span gas values determined by the
position of those switches into the ADC storage medium for each test.
c) Reason for Change: To allow the manufacturers the flexibility to
allow user access to the span gas concentration switches while
maintaining audit capability on the use of those switches.
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c' Section B. Automatic Leak Check (p. 43).
1. Item, Subsection 3. (p. 43).
a) .Previous Wording: Activation of the automatic leak-check system
shall cause the analyzer to automatically perform (or check) a span
sequence, automatically introduce span gas to the probe, compare the
difference between the span and probe readings, and make a pass or
fail determination.
b) New Wording: Activation of the automatic leak-check system shall
cause the analyzer to automatically perform (or check) a gas span
sequence, introduce span gas to the probe, compare the difference
between the gas span and the probe readings, and make a pass or fail
determination. Minimal activity by the operator (such as setting the
probe in a holder, adjusting probe flow to limits preset and checked
by the computer, capping the probe, etc. is permitted provided errors
resulting from improper operator action would be identified by the
computer and would require corrective action, or improper operator
action would tend to cause the system to fail a leak check.
c) Reason for Change: To clarify original intent.
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D. Section E. Dual Tailpipes (p. 45)
1. Item, Subsection 1.-4.. (p. 45)
a) Previous Concept: The dual tailpipe option provided for automatic
averaging of the results from each tailpipe.
b) New Concept: Delete requirement from Chapter VIII.
c) Reaspn for Change^ The number of vehicles in affected non-
attainment areas with true dual exhaust systems is expected to be
very small.
d) New Wording: E. [Deleted],
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E. Section H.. Vehicle Diagnosis, (p. 48)
1. Item, .Subsection 2. (p. 48)
a) Pr e vi pus Wo rd i n g: Activation of the "Vehicle Diagnosis" switch
shall allow the analyzer to continuously monitor the vehicle exhaust.
b) New Wor4J-ng: Activation of the "Vehicle Diagnosis" switch shall
allow the analyzer to continuously monitor the vehicle exhaust
regardless of inspection status (e.g. system needs weekly span check,
leak check, warm-up condition, etc.).
c) Reason for Change; Allows more flexible (but possibly less
accurate) use of the equipment for vehicle repair.
2. Item, Subsection 3. (p. 4.8)
a) Previous. Wording: The printer, or any automatic data collection
system, shall be prevented from operating anytime the analysis system
is in a "Vehicle Diagnosis" status.
b) New Wording.^ The printer, or any automatic data collection system,
shall be prevented from operating anytime the analysis system is in a
"Vehicle Diagnosis" status unless one of the options described in the
introduction to Chapter VIII is used.
c)
Reason for Change: Allow printer to be used in vehicle diagnosis.
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F. Section I. Anti-Tampering (p. 48)
1. Item,. Subsection 2. (p. 48)
a) Previous Wording: All switches or entry access for automotive
zero/span check adjustments, anti-dilution limits, span gas concen-
tration values, diagnostic switches, etc. shall be contained in a box
or other tamper-proof mechanism with provisions for an inspector's
seal. A gummed label with the inspectors initials and date which
must be torn to gain access, or a braided wire and crimped lead seal
(or similar device) would be sufficient for sealing.
b) New Wording,; All switches or entry access for automotive zero/span
check adjustments, anti-dilution limits, span gas concentration
values, diagnostic switches, etc. shall be contained in a box or
other tamper-proof mechanism with provisions for an inspector's
seal. Span gas concentration switches may be accessible to the user
if the switch values are printed for each test (see option in Section
A, subsection 6.). A gummed label with the inspectors initials (or
authorized stamp) and date which must be torn to gain access, or a
braided wire and crimped lead seal (or similar device) would be
sufficient for sealing.
c) ggason for Change: To make subsection 2. consistent with changes
in Subsections A.6. and 1.3.
^ Subsection 3. (p. 48)
a) Previous Wording: The tamper-proof system must allow convenient
access by an inspector.
b) New Wording: The tamper-proof system must allow convenient access
by an inspector or authorized service personnel.
c) Reason for Change: Allow service personnel to repair or adjust
analyzers.
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V. Modified Sections in Chapter IX
A. Section B.
1. Item, Subsection (all) (p. 52)
a) Previous Wording: B. [Deleted]
b) New Wording;
Dual Exhaust Systems
1. The system shall have the capability to automatically calculate
the average reading for dual tailpipes.
2. The dual tailpipe system shall use integrated test values from the
automatic read system for averaging.
3. Activation of dual tailpipe system shall allow two activations of
the automatic read system without activating the hang-up check
interlock.
4. The dual tailpipe system shall display the average value on
operator command, and hold the value until reset. The average value
is the value that would be forwarded to an automatic data collection
system.
c) Reason for Addition; To provide guidance for those programs that
choose the option to have the capability of testing dual exhaust
system vehicles and conveniently enter that data into an automatic
data collection system.
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B. Section C. Anti-Dilution (p. 53)
1. Item, Subsection 6. (p. 53)
a) Previous Wording; The C02 analyzer shall meet all of the
analyzer specifications in Chapter VII between C02 values of 6% and
14%. (CC>2 interference specification does not apply). Specifica-
tions in Chapter VIII apply to computer analyzers.
b) New Wording; The C02 analyzer shall meet all of the analyzer
specifications in Chapter VII between CC>2 values of 5% and 14%.
Exceptions are: 1) the C(>2 interference specification does not
apply, and 2) the uncertainty of the calibration curve shall be +0.9%
C&2 i° the range of 5-10% C02, and +0.5% C02 in the range of
10-14% C02- Specifications in Chapter VIII apply to computer
analyzers.
c) Reason for Change; The common method of adding a CC-2 analysis
capability to an HC/CO measurement system is to add a detector chip
to an existing sample cell. The length of the sample cell is very
critical in determining the accuracy and discrimination of an NDIR
analyzer. Fortunately, little compromise is necessary in selecting
the optimum sample cell length for HC and CO. Thus, the same sample
tube (cell) can be satisfactorily used for both HC and CO measure-
ment. Unfortunately, the optimum length for C02 measurement is
quite different than that for HC and CO measurement. Therefore, if
we want the economy of adding just a C02 detector chip to the HC/CO
sample tube, we must accept the type of accuracy that the non-optimum
C02 path length gives us. The alternative, if more accuracy is
required, would be to use an additional sample cell complete with IR
source, optics, detector, and electronics; in short another complete
optical bench, just for C02 measurement. The alternative approach
while being more accurate, in our judgment is not worth the cost.
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C. Section D. Loaded Mode Kit (p^ 54)
1. Item, Subsection 4. (p. 54)
a) Previous Wording: None - new subsection.
b) Nejw Wording: Alternatives to the 7°C maximum water trap tempera-
ture moisture-removal system are:
i) A 13°C maximum water trap temperature with corrections for
water content (electronic dew point, pressure, etc.) if the
system can be demonstrated to provide equivalent emission
results to the base water removal system.
ii) A..partial pressure type watertrap (permature @ etc.) may be
substituted for the base water removal system provided it can be
demonstrated to be as efficient in water removal.
iii) Any water removal system in conjunction with a heated
sample cell (with heated internal plumbing) and an electronic
water correction system (electronic dew point, pressure, .etc.)
may be used provided that the water removal system: 1) lowers
the sample gas temperature at least 8°C (14.4°F) below the
sample cell temperature; 2) the internal plumbing between the
water removal system and the sample cell does not allow the wall
temperature of the components to drop below the water removal
gas temperature; and 3) the overall system provides equivalent
emission results to the base water removal system.
c) Reason for Change: To allow the analyzer manufacturers more
flexibility in designing a loaded mode system.
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VI . Modified Sections in Chapter XI
Note: Throughout the test procedures, various test-point
values are required based on the analyzer specification
values. Revisions to some of these specifications (found
in report 80-5-C) may affect test-point or reference
values. Therefore, the reader is cautioned to carefully
check the test procedures to assure that values from 80-5-C
are used for evaluation testing.
A. Item, Introduction to Chapter XI (p. 59)
1. Previous Wording (Last Paragraph); The procedures as written are gener-
ally independent of tolerance specification values. Following each test
procedure, a reference value corresponding to the values given in Chapter
VII through X will be given in parenthesis.
2. New Wording: The procedures as written are generally independent of
tolerance specification values. Following each test procedure, a refer-
ence value corresponding to the values given in Chapter VII through X will
be given in parenthesis.
It is important to reemphasize that analyzer manufacturers may instrument
candidate analyzers to decrease set-up time during evaluation (see Chapter
VII introduction). An example of such pre-instrumentation is demonstrated
by the problem of obtaining an analog chart paper trace from a digital
readout or CRT display. Clarification of the type of pre-instrumentation
allowed was requested by several manufacturers. Most digital displays are
driven by BCD code. Many CRT final stage screen-writing electronics are
also driven by BCD. Chart recorders are now available that will accept a
BCD signal and print a stepped analog trace. Providing suitable add-on
signal conditioning equipment in order to buffer or parallel (with
parallel driver if necessary) the BCD signal output to the user readout
device or CRT screen-writer for the purpose of using a BCD chart recorder
would be an example of acceptable pre-instrumentation.
In addition to the general instructions given above, results from previous
testing performed for BAR 80 accreditation can be used in lieu of perform-
ing the tests listed in Table XI-1. Results can only be used from valid
tests performed as part of the accreditation procedure leading to full
accreditation. The data from the BAR 80 results is, however, subject to
the 3 year accreditation period (e.g. 1979 BAR 80 data could be used until
1982).
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Table XI-1
EPA Test Procedures For Which BAR 80 Results
May Be Substituted
EPA Test Procedure No.
C.2.
C.3.
C.4.
D.6.a.
E.3.a.
E.9.
E.10.
G.l.ii)
Description of Procedure
Sample Line Crush
Sample Handling Temperature Effect
Filter Check and Hang-up
Sample Line Flexibility
Altitude Compensation
Analyzer Electrical Inference - all except low
line-voltage testing
Propane to Hexane Conversion Factor
Low Temperature Environment
- all tests except warm-up and response time
c) Reason for Change: To add flexibility and to reduce evaluation testing
costs.
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TP: E.I. & 2.
B. Specific Test Procedure Changes
1. Section E. Subsection 1., Item b) i) (p. 72)
a) Previous Wording: If necessary, follow the manufacturer's
instructions for initial start-up and basic operating adjustments.
b) New Wording: If necessary, follow the manufacturer's instructions
for initial start-up and basic operating adjustments. If the
analyzer is equipped with an automatic read system, the auto-read
system may be used for this test.
c) Reason for Change; To add flexibility.
2. Section E. Subsection 3. Item a) v) (p. 77)
a) Previous Wording: None - adding a new subparagraph.
b) New Wording: An alternative test procedure may be used to evaluate
the analyzer's ability to be properly spanned at different
altitudes. The procedure consists of arbitrarily renaming the span
bottle used based on the expected density changes at the various test
altitudes. The new values are:
VH = (BARO/24) (span gas concentration)
VL = (BARO/31) (span gas concentration)
Where: BARO is in (in.HgA)
Use the standard gas span procedure to span to the Vjj and to the
VL values. See iv) for acceptance criteria.
c) Reason for Change: To add flexibility and reduce testing costs.
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TP: E.3.
3. Section E. Subsection 3, Item b) i) (p. 78)
a) Previous Wording; Testing concepts: This test procedure is to be
performed in order to identify the performance of any pressure or
temperature compensation systems under the various environmental
conditions that may be encountered during vehicle inspection
testing. In general, temperature compensation will be evaluated
during the more hostile environmental temperature tests .specified in
Section G. No other special testing would normally be necessary.
In order to evaluate pressure compensation systems, additional
testing is necessary. If the analyzer manufacturer can make a case
that testing the pressure compensation system in a manner similar to
the procedure specified in Chapter V Section E.3.a) (altitude
compensation) will represent actual analys'is system operating
conditions in the field, then that procedure (E.3.a) may be used for
check-out. If a sufficient case cannot be made, and a suitable
alternative test procedure cannot be determined, then performance
evaluations of the pressure compensation system must be carried out
in an altitude chamber. The pressure compenstion test shall be
conducted at each environmental temperature condition specified in
Chapter V. The tests shall be performed on each range of each
analyzer.
b) New Wording: Testing concepts: This test procedure is to be
performed in order to identify the performance of any pressure or
temperature 'compensation systems under the vairous environmental
conditions that may be encountered during vehicle inspection
testing. In general, temperature compensation will be evaluated
during the more hostile environmental temperature tests specified in
Section G. No other special testing would normally be necessary.
However, if the temperature compensation network does not compensate
for the full range of temperature specified in Section G, the
activation and deactivation temperatures of the system shall be
checked as well as the calibration curve uncertainty at a temperature
2°C above the actual activation temperature, and at a temperature 2°C
below the actual deactivation temperature. Checking of the activa-
tion temperature etc. may be performed during the Section G. check-
out.
In order to evaluate pressure compensation systems, additional
testing is necessary. If the analyzer manufacturer can make a case
that testing the pressure compensation system in a manner similar to
the procedure specified in Chapter V Section E.3.a) (altitude
compensation) or in any other manner (such as component testing) will
represent actual analysis system operating conditions in the field,
then that procedure (E.3.a. or other procedure justified by the
manufacturer) may be used for check-out. If a sufficient case cannot
be made, and a suitable alternative test procedure cannot be
determined, then performance evaluations of the pressure compensation
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TP: F.5. & G.I.
system must be carried out in an altitude chamber. The pressure
compenstion test shall be conducted at each environmental temperature
condition specified in Chapter V. The tests shall be performed on
each range of each analyzer.
c. Reason for Change: To be consistent with previous temperature
compensation changes and to allow more flexibility in the testing of
pressure compensation networks.
4. Section F. Subsection 5., Item b) xiv) (p. 104)
a) Previous Wording: None - adding a new subparagraph.
b) New Wording; Repeat steps i) through xiii) with the tee fitting
between the filter assembly and the leak check sensor.
c) Reason for Change; To compensate for and to test adequately
alternative leak-check systems that are allowed due to changes in
Chapter VII.F.5.
5. Section G. Subsection 1., Item b) (p. 105)
a) Previous Wording;
Test Conditions
i) 105°F (^5%°F) with a relative humidity between 80 and 85
percent (non-condensing).
ii) 40°F 0*5%°F) with a relative humidity between 75 and 80
percent with a 10 mph wind.
iii) 35°F (HH5%°F) with a relative humidity between 10 and 20
percent.
b) New Wording:
i) 105°F (jf5%°F) with a relative humidity ^between 80 and 85
percent (non-condensing).
ii) 40°F 0+5%°F) with a relative humidity between 75 and 80
percent with a 10 mph wind.
c) Reason for Change: Test conditions ii) and iii) were . somewhat
similar, therefore to reduce evaluation testing time and cost, test
condition iii) was dropped.
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