CNMV 99
Page 1, Totally 10 Pages
Technical Specification for Verification
and Inspection of Vehicle Exhaust
Emissions Analyzers
S/N CNMV 99
Rev.
1
1. This technical specification is enacted pursuant to Paragraph 2, Articles 14 and 16 of the
Weights and Measures Act.
2. The revision, date of promulgations, document No, date of enforcement and content of the
amendment are listed as follows:
In any case, the original Technical Specifications in Chinese are to be evidence.
NO GUARANTEE ON THE TRANSLATION
Rev. Date of Promulgation
1
21.05.2003
Document No.
(Ching-Piao-Szu-Tsu )
Date of Enforcement
No.09240004850
01.07.2003
Content of
Amendment
3. This specification is formulated with reference to the following international specifications:
OIML R99 Instruments for measuring vehicle exhaust emissions (1998)
Date of Promulgation Bureau of Standards, Metrology and Inspection, Date of Enforcement
21.05.2003
Ministry of Economic Affairs
01.07.2003
CNMV 99
1.
Page 2, Totally 10 Pages
Scope: The standard is applicable to analyzers for measuring exhaust emissions of in-use
motor vehicles with spark ignition engines.
2.
Structure:
2.1 Vehicle exhaust gas analyzers (hereinafter referred to as the “analyzer(s)”) shall have a
permanent and easily readable labels giving the following information:
(1) Manufacturer’s corporate name/trade mark;
(2) Year of manufacture;
(3) Class (0, Ⅰ and Ⅱ);
(4) Serial number of the analyzer and of the measuring transducer;
(5) Calibration flow rate, minimum and nominal sampling flow rate (SLPM);
(6) Nominal mains voltage, frequency and power required;
(7) Gas components and respective maximum measured value;
The label information defined above shall be correct, obvious and hard to be erased.
2.2 The value of the propane/hexane equivalency factor for each analyzer, and the warm-up
time for the instruments shall be marked permanently on the front panel of the analyzer
or shall be displayable on the indicating device.
2.3 For instruments with software-controlled metrological function, the identification of the
legally relevant software shall be marked permanently on the front panel of the
instrument or shall be displayable on the indicating device.
2.4 The measured result of the gas components shall be unambiguously expressed as “% vol.
CO”, “% vol. CO2” and “ppm vol. HC”. HC: the concentration of hydrocarbons shall be
expressed as n-hexane equivant via conversion factor.
2.5 The gas handling system shall contain a filter unit with replaceable element capable of
removing particles, it shall be possible to observe the degree of a filter’s contamination
without its removal, and it shall also be possible to replace, when necessary, this filter
easily without special tools.
2.6 The gas handling system shall contain a water separator that prevents water condensation
from forming in the measuring transducer.
2.7 In addition to the gas sampling port, instruments shall have a calibration port. Instruments
with an HC channel shall have a port for drawing in ambient air or other gas without
hydrocarbons, to provide a reference for zero-setting of the measuring instruments. If
used, ambient air shall pass through a charcoal filter or equivalent system.
2.8 The pump conveying the exhaust gas shall be mounted so that its vibrations do not affect
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the measurements; however, it shall not be possible to make a measurement when the
pump is switched off.
2.9 The minimum measuring range that may be subdivided shall be as given in Table 1.
Table 1
Measurand
Class
0, Ⅰ
Ⅱ
CO(1)
CO(2)
CO2
HC(1)
HC(2)
0% vol.
to
0% vol.
to
0% vol.
to
0 ppm vol.
to
0 ppm vol.
to
5% vol.
8% vol.
16% vol.
2000 ppm
vol.
14000 ppm
vol.
0% vol.
to
7% vol.
0% vol.
to
8% vol.
0% vol.
to
16% vol.
0 ppm vol.
to
2000 ppm
vol.
0 ppm vol.
to
14000 ppm
vol.
CO(1) and HC(1): the standard concentration of analyzer is suitable for car.
CO(2) and HC(2): the standard concentration of analyzer is suitable for motorcycle.
2.10 The minimum scale intervals of indication is specified below:
2.10.1 For analog instruments, the minimum scale intervals for CO, CO2 and HC shall be
comply with the requirements given in Table 2.
Table 2
Measurand
CO
CO2
HC(1)
0, Ⅰ
0.1% vol.
0.1% vol.
10 ppm vol.
Ⅱ
0.2% vol.
0.2% vol.
20 ppm vol.
Class
The minimum scale spacing shall be 1.25 mm. The thickness of the needle shall not be
greater than one quarter of the scale spacing. The needle shall overlap at least; one
third of the shortest mark and shall be clearly visible. The graduation shall be
designated with figures at least 5 mm high and designed in such away as to prevent
misinterpretation..
2.10.2 The digital figures for the instruments shall be at least 5 mm high. The least
significant figure of the display shall provide a resolution equal to or one order of
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magnitude higher than the values given in Table 3:
Table 3
Measurand
Class
0, Ⅰ
Ⅱ
CO
CO2
HC(1)
HC(2)
0.01% vol.
0.1% vol.
1 ppm vol.
10 ppm vol.
0.05% vol.
0.1% vol.
5 ppm vol.
20 ppm vol.
HC(1): the standard concentration of analyzer is suitable for car.
HC(2): the standard concentration of analyzer is suitable for motorcycle.
2.11 A battery-operated instrument shall either continue to function correctly or not indicate
any value whenever the voltage is below the manufacture’s specified value.
2.12 The instruments shall be equipped with the gas handling system for sampling, the
function for the indication of the flush and block.
2.13 The analyzer shall be equipped with an interface device for the serial digital RS-232 or
the analog signal to read the raw test data of the sampling and calibrating.
3. Verification, inspection and maximum permissible errors
3.1 The requirements of verification and inspection equipment are as follows:
(1) Standard gas: it should be traceable to national or international standard, except
hydrocarbons (the relative expanded uncertainty U is shown below), the other
relative expanded uncertainties shall be 1% or less.
HC(1): where HC(1) is below 1000 ppm, U is 2% or less; where HC(1) is between
1000 ppm to 2000 ppm, U is 1% or less.
HC(2): where HC(2) is below 7000 ppm, U is 2% or less; U is 1% or less, where
HC(1) is 7000 to 14000 ppm.
U is 2% or less, where the standard gas is used for verification and inspection of the
in-use instruments.
U: means the relative expanded uncertainty under 95% reliable levels and the
expanding coefficient is 2.
(2) Zero gas: High pure nitrogen with THC＜0.5ppm, CO＜1ppm, CO2＜1ppm and
H2O ＜5ppm.
(3) Stopwatch: facility shall measure over 8 hours and the minimum resolution of
indication is 0.1 sec or less.
(4) Thermometer: facility shall measure 5 to 40 oC upward, the minimum resolution of
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indication is 0.5 oC or less. The uncertainty shall be 1 oC or less.
(5) Pressure meter: facility shall measure 80-106 kPa upward, the minimum resolution of
indicatio is 2 kPa or less. The uncertainty shall be 5 kPa or less.
(6) Flow controller: facility shall measure 0-10 SLPM, the minimum resolution of
indicatio is 10SCCM or less, and the uncertainty shall be 300 sccm or less.
3.2 The verification and inspection items shall include the following tests:
(1) Appearance, structure and performance.
(2) Warm-up test (in use instruments need not perform this item).
(3) Response time test.
(4) Accuracy and reproducibility test.
(5) Leakage test.
(6) HC residue test (in use instruments need not perform this item).
(7) Low flow test.
3.3 The conduct of test items defined above shall conform the following condition:
3.3.1 The tests shall be performed using the standard gas given in Table 4.
Table 4
Gas component, concentration and serial number
Measurand
No. 1 gas
No. 2 gas
No. 3 gas
No. 4 gas
CO(1)
0.8% vol.10% 1.6% vol. 10% 3.2% vol.10% 4% vol.10%
CO(2)
3.2% vol.10% 4.8% vol. 10% 6.4% vol.10% 8% vol.10%
CO2
HC(1)
HC(2)
5.6% vol.10% 8.4% vol. 10%
11.2%
14% vol.10%
vol.10%
160 ppm vol.
320 ppm vol.
15%
15%
4800 ppm vol.
7200 ppm vol.
15%
10%
1280 ppm vol. 1600 ppm vol.
15%
15%
9600 ppm vol. 12000 ppm vol.
10%
10%
3.3.2 After the warm-up time, the instruments shall perform the test items immediately.
3.3.3 The span gas shall use the No. 4 gas to perform the calibration.
3.3.4 The verification and inspection tests performed in laboratory shall use the span gas
with labeled calibration-flow to perform the calibrated adjustment from the calibration
gas port of instruments. And the calibrated adjustment for the verification of the on
site instruments is performed with on site span gas. After the calibrated adjustment, all
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of the verification test items are performed from gas sampling port with the standard
gas No. 1, 2 and 3.
3.3.5 After inputting test-gas for 20 sec, just start to get the acquisition of sampling data. At
the same time take three continuous data to calculate the mean value as the record
basis.
3.3.6 While performing calibration and test through the gas sampling port and drawing-type
calibration port, the flow rate of the sample and span gas shall be greater than the
labeled flow on the instruments, so that the superfluous test-gas can flow out from the
branch.
3.3.7 capillary–type calibration inlet shall take off the tube from calibration port and
connect to the standard gas system to do the verification and inspection test.
3.3.8 The test through the sampling gas inlet means that the test gas must go through the gas
handling system that contains the sampling probe and pre-filter unit.
3.4 Warm-up test: immediately after either the instruments warm-up period has elapsed or an
automatic warm-up lockout has been deactivated, perform a span adjustment within 1
minute; then at time intervals of 2 min, 5 min and 15 min after warm-up, perform a
measurement with No. 3 gas.The difference between any of the four measured value and
individual 3 test results shall not exceed the modulus of the maximum permissible error
on initial verification.
3.5 Response time test: A measurement shall be employed for instantly changing from the
instrument flush of the zero gas to sampling the No. 1 gas through the probe at ambient
pressure. For measuring CO, HC, instruments including the specified gas handling
system shall indicate 90% of the final value within 10 sec or less after changing from a
gas with zero content.
3.6 Rated operation conditions
Main voltage: -15% to +10% of the nominal voltage, and 2% of nominal frequency.
Under the rated operation condition of instruments, the error of measuring instruments
for the verification and inspection test shall perform the calibration adjustment at the zero
and span with No. 4 gas first, then proceed three-cycle consecutive measurements with
No. 1, 2, 3 gas concentration, and the three-time mean of the standard deviation for each
measurand is the result of the reproducibility test. The difference between the three-time
average and certificate value for each measurand is the error of measuring instruments for
the result of the accuracy test.
3.7 Maximum permissible errors on the verification
3.7.1 The maximum permissible errors given in Table 5 shall apply for instruments on initial
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verification.
Table 5
Measurand
Class
CO(1)
CO(2)
CO2
HC(1)
HC(2)
O
a+ 0.03% vol. 0.06% vol. 0.5% vol.
b+
5%
5%
5%
10 ppm
70 ppm vol.
vol.
5%
5%
Ⅰ
a+ 0.06% vol. 0.12% vol. 0.5% vol.
b+
5%
5%
5%
12 ppm
84 ppm vol.
vol.
5%
5%
Ⅱ
a+ 0.2% vol. 0.2% vol.
b+
10%
10%
1% vol.
10%
30 ppm
vol.
210 ppm
vol.
10%
10%
+ Absolute or relative, whichever is greater.
a+ : The absolute error of measurement .
b+ : The relative error of measurement.3.7.2
The maximum permissible errors given in
Table 6 shall apply for instruments on subsequent verification.
Table 6
Measurand
Class
O
Ⅰ
Ⅱ
CO(1)
CO(2)
CO2
a+ 0.04% vol. 0.08% vol. 0.5% vol.
b+
8%
8%
8%
a+ 0.08% vol. 0.16% vol. 0.5% vol.
b+
8%
8%
8%
a+
b+
0.2% vol. 0.2% vol.
10%
10%
1% vol.
10%
HC(1)
HC(2)
16 ppm
vol.
112 ppm
vol.
8%
8%
19 ppm
vol.
133 ppm
vol.
8%
8%
30 ppm
vol.
210 ppm
vol.
10%
10%
+ Absolute or relative, whichever is greater.
a+ : The absolute error of measurement .
b+ : The relative error of measurement.
3.8 The maximum permissible errors on the inspection and verification are identical.
3.9 The result of the accuracy test shall not be greater than the maximum permissible errors
on verification, and the result of the reproducibility test for the No. 2 gas shall not be
greater than one fourth of the maximum permissible errors on verification.
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3.10 Leakage test: an adjustable leakage device shall be introduced artificially into the gas
handling system near the sampling port, then adjust the leakage with zero gas for the No.
1 gas to proceed the dilution measurement, when the difference of the indication and
certificate value is greater than the half of the maximum permissible errors, without
disturbing the artificial leak, remove the calibration gas supplied at the probe, and
conduct the leakage test procedure as described in the manufacture’s operating
instructions to check whether the instruments equip with the function of the leakage test.
3.11 The gas handling system shall be airtight to such an extent that the influence of dilution
with ambient air on the measuring results shall not be more than half the modulus of the
maximum permissible error on verification. Class 0 or class Ⅰ instruments shall not be
able to make a measurement if leakage of the gas handling system is found by leakage
test.
3.12 HC residue test: immediately after the sampling at least 5 min with No. 4 gas, conduct an
HC residue check as described by the manufacture’s operating instructions, and the
instruments shall stop the residue test within 30 sec. and take the HC records. Repeat this
operation three times, and then supply the No. 3 gas to check compliance with the
maximum permissible error on verification of the accuracy test.
3.13 The three-time HC residue values of the HC-residue-check test shall be less than twice of
the absolute maximum permissible error of the class 0 measurand, and the following
maximum permissible error on verification of the accuracy test shall not be more than
half of the maximum permissible error of the test gas. The class 0 or class Ⅰ
instruments shall not be able to make a measurement if the HC residue value exceeds too
high.
3.14 Low flow test: a measurement shall be performed with a No. 1 gas that is initially
supplied to the gas handling system at a gas flow rate greater than the minimum required
by the tested instrument. During the measurement, the gas flow rate shall be gradually
reduced. When the difference of the indication and certificate value is greater than the
half the modulus of the maximum permissible error on verification, the instrument shall
indicate the low flow responds, and for class 0 or class Ⅰ instruments, when that limit is
reached, the device shall prevent measurement.
3.15 The term of validity of the verification for the instruments is one year from the first day
of the next month since the date affixed with a verified conformity mark.
3.16 New instruments and the other instruments that has changed sensors or software version
in the term of validity of the verification shall perform a verification test in laboratory.
4. The verification compliance marks
4.1 The place of verification compliance marks of the instruments shall be on the front and
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obvious, affixed a verification compliance tag on the instrument.
4.2 After the instrument passed verification, a verification compliance certificate shall be
issued.
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Attached Table
Table 1: Verification Compliance Certificate
Bureau of Standards, Metrology and Inspection
○○○○○
Verification Compliance Certificate of Vehicle Exhaust Emissions Analyzer
1. Applicant
:
2. Address
:
3. Specification
:
4. Brand
:
5. Type No.
:
6. Instrument No
: Primer:
Sensor:
7. Category
:
8. Class
:
9. Verification Compliance Tag No.:
10. Date of Verification
: yy/mm/dd
11. Date of Expiry
: yy/mm/dd
Within the validity period, vehicle exhaust emissions analyzers should run
checking tests periodically with traced and certified standard gas in order to apply
the analyzer in legal tests continuously.
Date: yy/mm/dd.