Commission Regulation (EC) No 692/2008 of 18 July 2008 implementing and amending Regulation (EC) No 715/2007 of the European Parliament and of the Council on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information (Text with EEA relevance) (c. 692)

[F1ANNEX IIIA U.K. VERIFYING REAL DRIVING EMISSIONS

Textual Amendments

F1 Inserted by Commission Regulation (EU) 2016/427 of 10 March 2016 amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6) (Text with EEA relevance).

Appendix 3

Validation of PEMS and non-traceable exhaust mass flow rate U.K.

1. INTRODUCTION U.K.

This appendix describes the requirements to validate under transient conditions the functionality of the installed PEMS as well as the correctness of the exhaust mass flow rate obtained from non-traceable exhaust mass flow meters or calculated from ECU signals.

2. SYMBOLS U.K.

—

per cent

#/km

—

number per kilometre

a ₀

—

y intercept of the regression line

a ₁

—

slope of the regression line

g/km

—

gramme per kilometre

—

hertz

—

kilometre

—

metre

mg/km

—

milligramme per kilometre

r ²

—

coefficient of determination

—

actual value of the reference signal

—

actual value of the signal under validation

3. VALIDATION PROCEDURE FOR PEMS U.K.

3.1. Frequency of PEMS validation U.K.

It is recommended to validate the installed PEMS once for each PEMS-vehicle combination either before the test or, alternatively, after the completion of an on-road test. The PEMS installation shall be kept unchanged in the time period between the on-road test and the validation.

3.2. PEMS validation procedure U.K.

3.2.1. PEMS installation U.K.

The PEMS shall be installed and prepared according to the requirements of Appendix 1. After the completion of the validation test until the start of the on-road test, the PEMS installation shall not be changed.

3.2.2. Test conditions U.K.

The validation test shall be conducted on a chassis dynamometer, as far as applicable, under type-approval conditions by following the requirements of Annex 4a to UN/ECE Regulation No 83, 07 series of amendments or any other adequate measurement method. It is recommended to conduct the validation test with the worldwide harmonised light vehicles test cycle (WLTC) as specified in Annex 1 to UNECE Global Technical Regulation No 15. The ambient temperature shall be within the range specified in point 5.2 of this Annex.

It is recommended to feed the exhaust flow extracted by the PEMS during the validation test back to the CVS. If this is not feasible, the CVS results shall be corrected for the extracted exhaust mass. If the exhaust mass flow rate is validated with an exhaust mass flow meter, it is recommended to cross-check the mass flow rate measurements with data obtained from a sensor or the ECU.

3.2.3. Data analysis U.K.

The total distance-specific emissions [g/km] measured with laboratory equipment shall be calculated following Annex 4a to UN/ECE Regulation No 83, 07 series of amendments. The emissions as measured with the PEMS shall be calculated according to point 9 of Appendix 4, summed to give the total mass of pollutant emissions [g] and then divided by the test distance [km] as obtained from the chassis dynamometer. The total distance-specific mass of pollutants [g/km], as determined by the PEMS and the reference laboratory system, shall be compared and evaluated against the requirements specified in point 3.3. For the validation of NO _X emission measurements, humidity correction shall be applied following point 6.6.5 of Annex 4a to UN/ECE Regulation No 83, 07 series of amendments.

3.3. Permissible tolerances for PEMS validation U.K.

The PEMS validation results shall fulfil the requirements given in Table 1. If any permissible tolerance is not met, corrective action shall be taken and the PEMS validation shall be repeated.

Table 1

Permissible tolerances

Parameter [Unit]	Permissible tolerance
^a Only applicable if vehicle speed is determined by the ECU; to meet the permissible tolerance it is permitted to adjust the ECU vehicle speed measurements based on the outcome of the validation test.
^b Parameter only mandatory if measurement required by Annex IIIA, Section 2.1.
^c Still to be determined.
Distance [km] ^a	± 250 m of the laboratory reference
THC ^b [mg/km]	± 15 mg/km or 15 % of the laboratory reference, whichever is larger
CH ₄ ^b [mg/km]	± 15 mg/km or 15 % of the laboratory reference, whichever is larger
NMHC ^b [mg/km]	± 20 mg/km or 20 % of the laboratory reference, whichever is larger
PN ^b [#/km]	^c
CO ^b [mg/km]	± 150 mg/km or 15 % of the laboratory reference, whichever is larger
CO ₂ [g/km]	± 10 g/km or 10 % of the laboratory reference, whichever is larger
NO _x ^b [mg/km]	± 15 mg/km or 15 % of the laboratory reference, whichever is larger

4. VALIDATION PROCEDURE FOR THE EXHAUST MASS FLOW RATE DETERMINED BY NON-TRACEABLE INSTRUMENTS AND SENSORS U.K.

4.1. Frequency of validation U.K.

In addition to fulfilling the linearity requirements of point 3 of Appendix 2 under steady-state conditions, the linearity of non-traceable exhaust mass flow meters or the exhaust mass flow rate calculated from non-traceable sensors or ECU signals shall be validated under transient conditions for each test vehicle against a calibrated exhaust mass flow meter or the CVS. The validation test procedure can be executed without the installation of the PEMS but shall generally follow the requirements defined in Annex 4a to UN/ECE Regulation No 83, 07 series of amendments and the requirements pertinent to exhaust mass flow meters defined in Appendix 1.

4.2. Validation procedure U.K.

The validation test shall be conducted on a chassis dynamometer under type-approval conditions, as far as applicable, by following the requirements of Annex 4a to UN/ECE Regulation No 83, 07 series of amendments. The test cycle shall be the worldwide harmonised light vehicles test cycle (WLTC) as specified in Annex 1 to UNECE Global Technical Regulation No 15. As reference, a traceably calibrated flow meter shall be used. The ambient temperature can be any within the range specified in point 5.2 of this Annex. The installation of the exhaust mass flow meter and the execution of the test shall fulfil the requirement of point 3.4.3 of Appendix 1 of this Annex.

The following calculation steps shall be taken to validate the linearity:

(a)

The signal under validation and the reference signal shall be time corrected by following, as far as applicable, the requirements of point 3 of Appendix 4.

(b)

Points below 10 % of the maximum flow value shall be excluded from the further analysis.

(c)

At a constant frequency of at least 1,0 Hz, the signal under validation and the reference signal shall be correlated using the best-fit equation having the form:

y = a ₁ x + a ₀

where:

is the actual value of the signal under validation

a ₁

is the slope of the regression line

is the actual value of the reference signal

a ₀

is the y intercept of the regression line

The standard error of estimate (SEE) of y on x and the coefficient of determination (r ² ) shall be calculated for each measurement parameter and system.

(d)

The linear regression parameters shall meet the requirements specified in Table 2.

4.3. Requirements U.K.

The linearity requirements given in Table 2 shall be fulfilled. If any permissible tolerance is not met, corrective action shall be taken and the validation shall be repeated.

Table 2

Linearity requirements of calculated and measured exhaust mass flow

Measurement parameter/system	a ₀	Slope a ₁	Standard error SEE	Coefficient of determination r ²
Exhaust mass flow	0,0 ± 3,0 kg/h	1,00 ± 0,075	≤ 10 % max	≥ 0,90]