Commission Regulation (EU) 2017/1151 of 1 June 2017 supplementing 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, amending Directive 2007/46/EC of the European Parliament and of the Council, Commission Regulation (EC) No 692/2008 and Commission Regulation (EU) No 1230/2012 and repealing Commission Regulation (EC) No 692/2008 (Text with EEA relevance)

• (h) The linear regression parameters shall meet the requirements specified in Table A5/1.

3.4.3.   Requirements for linearity verification on a chassis dynamometer

Non-traceable flow-measuring instruments, sensors or ECU signals, that cannot directly be calibrated according to traceable standards, shall be calibrated on a chassis dynamometer. The procedure shall follow, as far as applicable, the requirements of UN Regulation No 154. If necessary, the instrument or sensor to be calibrated shall be installed on the test vehicle and operated according to the requirements of Appendix 4. The calibration procedure shall follow whenever possible the requirements of paragraph 3.4.2. At least 10 appropriate reference values shall be selected as to ensure that at least 90 per cent of the maximum value expected to occur during the RDE test is covered.

If a non-traceable flow-measuring instrument, sensor or ECU signal for determining exhaust flow is to be calibrated, a reference exhaust mass flow meter with traceable calibration or the CVS shall be attached to the vehicle’s tailpipe. It shall be ensured that the vehicle exhaust is accurately measured by the exhaust mass flow meter according to paragraph 3.4.3. of Appendix 4. The vehicle shall be operated by applying constant throttle at a constant gear selection and chassis dynamometer load.

4.1.   Permissible types of analysers

4.1.1.   Standard analysers

The gaseous components shall be measured with analysers specified in paragraph 4.1.4., Annex B5 to UN Regulation No 154. If an NDUV analyser measures both NO and NO2, a NO2/NO converter is not required.

4.1.2.   Alternative analysers

Any analyser not meeting the design specifications of paragraph 4.1.1. is permissible provided that it fulfils the requirements of paragraph 4.2. The manufacturer shall ensure that the alternative analyser achieves an equivalent or higher measurement performance compared to a standard analyser over the range of pollutant concentrations and co-existing gases that can be expected from vehicles operated with permissible fuels under moderate and extended conditions of valid RDE testing as specified in paragraphs 5., 6. and 7. of this Appendix. Upon request, the manufacturer of the analyser shall submit in writing supplemental information, demonstrating that the measurement performance of the alternative analyser is consistently and reliably in line with the measurement performance of standard analysers. Supplemental information shall contain:

• (a) a description of the theoretical basis and the technical components of the alternative analyser;

• (b) a demonstration of equivalency with the respective standard analyser specified in paragraph 4.1.1. over the expected range of pollutant concentrations and ambient conditions of the type-approval test defined in UN Regulation No 154 as well as a validation test as described in paragraph 3. of Appendix 6 for a vehicle equipped with a spark-ignition and compression-ignition engine; the manufacturer of the analyser shall demonstrate the significance of equivalency within the permissible tolerances given in paragraph 3.3. of Appendix 6.

• (c) a demonstration of equivalency with the respective standard analyser specified in paragraph 4.1.1. with respect to the influence of atmospheric pressure on the measurement performance of the analyser; the demonstration test shall determine the response to span gas having a concentration within the analyser range to check the influence of atmospheric pressure under moderate and extended altitude conditions defined in paragraph 5.2. Such a test can be performed in an altitude environmental test chamber.

- (d) a demonstration of equivalency with the respective standard analyser specified in paragraph 4.1.1. over at least three on-road tests that fulfil the requirements of this Appendix.

- (e) a demonstration that the influence of vibrations, accelerations and ambient temperature on the analyser reading does not exceed the noise requirements for analysers set out in paragraph 4.2.4.

Approval authorities may request additional information to substantiate equivalency or refuse approval if measurements demonstrate that an alternative analyser is not equivalent to a standard analyser.

4.2.   Analyser specifications

4.2.1.   General

In addition to the linearity requirements defined for each analyser in paragraph 3., the compliance of analyser types with the specifications laid down in paragraphs 4.2.2. to 4.2.8. shall be demonstrated by the analyser manufacturer. Analysers shall have a measuring range and response time appropriate to measure with adequate accuracy the concentrations of the exhaust gas components at the applicable emissions standard under transient and steady state conditions. The sensitivity of the analysers to shocks, vibration, aging, variability in temperature and air pressure as well as electromagnetic interferences and other impacts related to vehicle and analyser operation shall be limited as far as possible.

4.2.2.   Accuracy

The accuracy, defined as the deviation of the analyser reading from the reference value, shall not exceed 2 per cent of reading or 0.3 per cent of full scale, whichever is larger.

4.2.3.   Precision

The precision, defined as 2.5 times the standard deviation of 10 repetitive responses to a given calibration or span gas, shall be no greater than 1 per cent of the full scale concentration for a measurement range equal or above 155 ppm (or ppmC1) and 2 per cent of the full scale concentration for a measurement range of below 155 ppm (or ppmC1).

4.2.4.   Noise

The noise shall not exceed 2 per cent of full scale. Each of the 10 measurement periods shall be interspersed with an interval of 30 seconds in which the analyser is exposed to an appropriate span gas. Before each sampling period and before each span period, sufficient time shall be given to purge the analyser and the sampling lines.

4.2.5.   Zero response drift

The drift of the zero response, defined as the mean response to a zero gas during a time interval of at least 30 seconds, shall comply with the specifications given in Table A5/2.

4.2.6.   Span response drift

The drift of the span response, defined as the mean response to a span gas during a time interval of at least 30 seconds, shall comply with the specifications given in Table A5/2.

Table A5/2

Permissible zero and span response drift of analysers for measuring gaseous components under laboratory conditions

| Pollutant | Absolute Zero response drift | Absolute Span response drift |

| --- | --- | --- | | CO2 | ≤ 1000 ppm over 4 h | ≤ 2 % of reading or ≤ 1000 ppm over 4 h, whichever is larger | | CO | ≤ 50 ppm over 4 h | ≤ 2 % of reading or ≤ 50 ppm over 4 h, whichever is larger | | PN | 5 000 particles per cubic centimetre over 4 h | According to manufacturer specifications | | NOX | ≤ 3 ppm over 4 h | ≤ 2 % of reading or 3 ppm over 4 h, whichever is larger | | CH4 | ≤ 10 ppm C1 | ≤ 2 % of reading or ≤ 10 ppm C1 over 4 h, whichever is larger | | THC | ≤ 10 ppm C1 | ≤ 2 % of reading or ≤ 10 ppm C1 over 4 h, whichever is larger |

4.2.7.   Rise time

The rise time, defined as the time between the 10 per cent and 90 per cent response of the final reading (t

10 to t 90; see paragraph 4.4.), shall not exceed 3 seconds.

4.2.8.   Gas drying

Exhaust gases may be measured wet or dry. A gas-drying device, if used, shall have a minimal effect on the composition of the measured gases. Chemical dryers are not permitted.

4.3.   Additional requirements

4.3.1.   General

The provisions in paragraphs 4.3.2. to 4.3.5. define additional performance requirements for specific analyser types and apply only to cases in which the analyser under consideration is used for RDE emission measurements.

4.3.2.   Efficiency test for NOX converters

If a NOX converter is applied, for example to convert NO2 into NO for analysis with a chemiluminescence analyser, its efficiency shall be tested by following the requirements in paragraph 5.5. of Annex B5 to UN Regulation No 154. The efficiency of the NOX converter shall be verified no longer than one month before the emissions test.

4.3.3.   Adjustment of the Flame Ionisation Detector (FID)

- (a) Optimization of the detector response

If hydrocarbons are measured, the FID shall be adjusted as specified by the instrument manufacturer. A propane-in-air or propane-in-nitrogen span gas shall be used to optimize the response in the most common operating range.

• (b) Hydrocarbon response factors If hydrocarbons are measured, the hydrocarbon response factor of the FID shall be verified by following the provisions of paragraph 5.4.3. of Annex B5 to UN Regulation No 154, using propane-in-air or propane-in-nitrogen as span gases and purified synthetic air or nitrogen as zero gases, respectively.

• (c) Oxygen interference check The oxygen interference check shall be performed when introducing a FID into service and after major maintenance intervals. A measuring range shall be chosen in which the oxygen interference check gases fall in the upper 50 per cent. The test shall be conducted with the oven temperature set as required. The specifications of the oxygen interference check gases are described in paragraph 5.3. The following procedure applies:
• (i) The analyser shall be set at zero;
• (ii) The analyser shall be spanned with a 0 per cent oxygen blend for positive ignition engines and a 21 per cent oxygen blend for compression ignition engines;
• (iii) The zero response shall be rechecked. If it has changed by more than 0.5 per cent of full scale, steps (i) and (ii) shall be repeated;
• (iv) The 5 per cent and 10 per cent oxygen interference check gases shall be introduced;
• (v) The zero response shall be rechecked. If it has changed by more than ±1 per cent of full scale, the test shall be repeated;
• (vi) The oxygen interference E O2 [%] shall be calculated for each oxygen interference check gas in step (iv) as follows: Image omitted; see official source where the analyser response is: Image omitted; see official source where: c ref,b

is the reference HC concentration in step (ii) [ppmC1] c ref,d

is the reference HC concentration in step (iv) [ppmC1]

c FS,b

is the full scale HC concentration in step (ii) [ppmC1] c FS,d

is the full scale HC concentration in step (iv) [ppmC1] c m,b

is the measured HC concentration in step (ii) [ppmC1] c m,d

is the measured HC concentration in step (iv) [ppmC1] - (vii) The oxygen interference E O2 shall be less than ±1.5 per cent for all required oxygen interference check gases. - (viii) If the oxygen interference E O2 is higher than ±1.5 per cent, corrective action may be taken by incrementally adjusting the air flow (above and below the manufacturer's specifications), the fuel flow and the sample flow. - (ix) The oxygen interference check shall be repeated for each new setting.

4.3.4.   Conversion efficiency of the non-methane cutter (NMC)

If hydrocarbons are analysed, a NMC can be used to remove non-methane hydrocarbons from the gas sample by oxidizing all hydrocarbons except methane. Ideally, the conversion for methane is 0 per cent and for the other hydrocarbons, represented by ethane, is 100 per cent. For the accurate measurement of NMHC, the two efficiencies shall be determined and used for the calculation of the NMHC emissions (see paragraph 6.2. of Appendix 7). It is not necessary to determine the methane conversion efficiency in the case where the NMC-FID is calibrated according to method (b) in paragraph 6.2. of Appendix 7 by passing the methane/air calibration gas through the NMC.

- (a) Methane conversion efficiency

Methane calibration gas shall be flowed through the FID with and without bypassing the NMC; the two concentrations shall be recorded. The methane efficiency shall be determined as: Image omitted; see official source where: c HC(w/NMC)

is the HC concentration with CH4 flowing through the NMC [ppmC1] c HC(w/o NMC)

is the HC concentration with CH4 bypassing the NMC [ppmC1]

• (b) Ethane conversion efficiency Ethane calibration gas shall be flowed through the FID with and without bypassing the NMC; the two concentrations shall be recorded. The ethane efficiency shall be determined as: Image omitted; see official source where: c HC(w/NMC)

is the HC concentration with C2H6 flowing through the NMC [ppmC1] c HC(w/o NMC)

is the HC concentration with C2H6 bypassing the NMC [ppmC1]

4.3.5.   Interference effects

- (a) General

Other gases than the ones being analysed can affect the analyser reading. A check for interference effects and the correct functionality of analysers shall be performed by the analyser manufacturer prior to market introduction at least once for each type of analyser or device addressed in paragraphs 4.3.5. (b) to (f).

• (b) CO analyser interference check Water and CO2 can interfere with the measurements of the CO analyser. Therefore, a CO2 span gas, having a concentration of 80 to 100 per cent of the full scale of the maximum operating range of the CO2 analyser used during the test, shall be bubbled through water at room temperature and the analyser response recorded. The analyser response shall not be more than 2 per cent of the mean CO concentration expected during normal on-road testing or ± 50 ppm, whichever is larger. The interference check for H2O and CO2 may be run as separate procedures. If the H2O and CO2 levels used for the interference check are higher than the maximum levels expected during the test, each observed interference value shall be scaled down by multiplying the observed interference with the ratio of the maximum expected concentration value during the test and the actual concentration value used during this check. Separate interference checks with concentrations of H2O that are lower than the maximum concentration expected during the test may be run and the observed H2O interference shall be scaled up by multiplying the observed interference with the ratio of the maximum H2O concentration value expected during the test and the actual concentration value used during this check. The sum of the two scaled interference values shall meet the tolerance specified in this point.

- (c) NOX analyser quench check

The two gases of concern for CLD and HCLD analysers are CO2 and water vapour. The quench response to these gases is proportional to the gas concentrations. A test shall determine the quench at the highest concentrations expected during the test. If the CLD and HCLD analysers use quench compensation algorithms that utilize H2O or CO2 measurement analysers or both, quench shall be evaluated with these analysers active and with the compensation algorithms applied. - (i) CO2 quench check A CO2 span gas having a concentration of 80 to 100 per cent of the maximum operating range shall be passed through the NDIR analyser; the CO2 value shall be recorded as A. The CO2 span gas shall then be diluted by approximately 50 per cent with NO span gas and passed through the NDIR and CLD or HCLD; the CO2 and NO values shall be recorded as B and C, respectively. The CO2 gas flow shall then be shut off and only the NO span gas shall be passed through the CLD or HCLD; the NO value shall be recorded as D. The per cent quench shall be calculated as: Image omitted; see official source where: A

is the undiluted CO2 concentration measured with the NDIR [%] B

is the diluted CO2 concentration measured with the NDIR [%]

C

is the diluted NO concentration measured with the CLD or HCLD [ppm] D

is the undiluted NO concentration measured with the CLD or HCLD [ppm]

Alternative methods of diluting and quantifying of CO2 and NO span gas values such as dynamic mixing/blending are permitted upon approval of the approval authority. - (ii) Water quench check This check applies to measurements of wet gas concentrations only. The calculation of water quench shall consider dilution of the NO span gas with water vapour and the scaling of the water vapour concentration in the gas mixture to concentration levels that are expected to occur during an emissions test. A NO span gas having a concentration of 80 per cent to 100 per cent of full scale of the normal operating range shall be passed through the CLD or HCLD; the NO value shall be recorded as D. The NO span gas shall then be bubbled through water at room temperature and passed through the CLD or HCLD; the NO value shall be recorded as Cb. The analyser's absolute operating pressure and the water temperature shall be determined and recorded as E and F, respectively. The mixture's saturation vapour pressure that corresponds to the water temperature of the bubbler F shall be determined and recorded as G. The water vapour concentration H [%] of the gas mixture shall be calculated as: Image omitted; see official source The expected concentration of the diluted NO-water vapour span gas shall be recorded as D e after being calculated as: Image omitted; see official source For diesel exhaust, the maximum concentration of water vapour in the exhaust gas (in per cent) expected during the test shall be recorded as H m after being estimated, under the assumption of a fuel H/C ratio of 1.8/1, from the maximum CO2 concentration in the exhaust gas A as follows: Image omitted; see official source The per cent water quench shall be calculated as: Image omitted; see official source where: D e

is the expected diluted NO concentration [ppm] Cb

is the measured diluted NO concentration [ppm] H m

is the maximum water vapour concentration [%]

H

is the actual water vapour concentration [%] - (iii) Maximum allowable quench The combined CO2 and water quench shall not exceed 2 per cent of full scale.

- (d) Quench check for NDUV analysers

Hydrocarbons and water can positively interfere with NDUV analysers by causing a response similar to that of NOX. The manufacturer of the NDUV analyser shall use the following procedure to verify that quench effects are limited: - (i) The analyser and chiller shall be set up by following the operating instructions of the manufacturer; adjustments should be made as to optimise the analyser and chiller performance. - (ii) A zero calibration and span calibration at concentration values expected during emissions testing shall be performed for the analyser. - (iii) A NO2 calibration gas shall be selected that matches as far as possible the maximum NO2 concentration expected during emissions testing. - (iv) The NO2 calibration gas shall overflow at the gas sampling system's probe until the NOX response of the analyser has stabilised. - (v) The mean concentration of the stabilized NOX recordings over a period of 30 s shall be calculated and recorded as NOX,ref. - (vi) The flow of the NO2 calibration gas shall be stopped and the sampling system saturated by overflowing with a dew point generator's output, set at a dew point of 50 °C. The dew point generator's output shall be sampled through the sampling system and chiller for at least 10 minutes until the chiller is expected to be removing a constant rate of water. - (vii) Upon completion of (vi), the sampling system shall again be overflown by the NO2 calibration gas used to establish NOX,ref until the total NOX response has stabilized. - (viii) The mean concentration of the stabilized NOX recordings over a period of 30 s shall be calculated and recorded as NOX,m. - (ix) NOX,m shall be corrected to NOX,dry based upon the residual water vapour that passed through the chiller at the chiller's outlet temperature and pressure. The calculated NOX,dry shall at least amount to 95 % of NOX,ref.

- (e) Sample dryer

A sample dryer removes water, which can otherwise interfere with the NOX measurement. For dry CLD analysers, it shall be demonstrated that at the highest expected water vapour concentration H m the sample dryer maintains the CLD humidity at ≤ 5 g water/kg dry air (or about 0.8 per cent H2O), which is 100 per cent relative humidity at 3.9 °C and 101.3 kPa or about 25 per cent relative humidity at 25 °C and 101.3 kPa. Compliance may be demonstrated by measuring the temperature at the outlet of a thermal sample dryer or by measuring the humidity at a point just upstream of the CLD. The humidity of the CLD exhaust might also be measured as long as the only flow into the CLD is the flow from the sample dryer.

• (f) Sample dryer NO2 penetration Liquid water remaining in an improperly designed sample dryer can remove NO2 from the sample. If a sample dryer is used in combination with a NDUV analyser without an NO2/NO converter upstream, water could therefore remove NO2 from the sample prior to the NOX measurement. The sample dryer shall allow for measuring at least 95 per cent of the NO2 contained in a gas that is saturated with water vapour and consists of the maximum NO2 concentration expected to occur during emission testing.

4.4.   Response time check of the analytical system

For the response time check, the settings of the analytical system shall be exactly the same as during the emissions test (i.e. pressure, flow rates, filter settings in the analysers and all other parameters influencing the response time). The response time shall be determined with gas switching directly at the inlet of the sample probe. The gas switching shall be done in less than 0.1 second. The gases used for the test shall cause a concentration change of at least 60 per cent full scale of the analyser.

The concentration trace of each single gas component shall be recorded.

For time alignment of the analyser and exhaust flow signals, the transformation time is defined as the time from the change (t 0) until the response is 50 per cent of the final reading (t 50).

The system response time shall be ≤ 12 s with a rise time of ≤ 3 seconds for all components and all ranges used. When using a NMC for the measurement of NMHC, the system response time may exceed 12 seconds.

5. GASES

5.1.   Calibration and span gases for RDE tests

5.1.1.   General

The shelf life of calibration and span gases shall be respected. Pure as well as mixed calibration and span gases shall fulfil the specifications of Annex B5 of UN Regulation No 154.

5.1.2.   NO2 calibration gas

In addition, NO2 calibration gas is permissible. The concentration of the NO2 calibration gas shall be within two per cent of the declared concentration value. The amount of NO contained in the NO2 calibration gas shall not exceed 5 per cent of the NO2 content.

5.1.3.   Multicomponent mixtures

Only multicomponent mixtures which fulfil the requirements of paragraph 5.1.1. shall be used. These mixtures may contain two or more of the components. Multicomponent mixtures containing both NO and NO2 are exempted of the NO2 impurity requirement set out in paragraphs 5.1.1. and 5.1.2.

5.2.   Gas dividers

Gas dividers (i.e., precision blending devices that dilute with purified N2 or synthetic air) can be used to obtain calibration and span gases. The accuracy of the gas divider shall be such that the concentration of the blended calibration gases is accurate to within ± 2 per cent. The verification shall be performed at between 15 and 50 per cent of full scale for each calibration incorporating a gas divider. An additional verification may be performed using another calibration gas, if the first verification has failed.

Optionally, the gas divider may be checked with an instrument which by nature is linear, e.g. using NO gas in combination with a CLD. The span value of the instrument shall be adjusted with the span gas directly connected to the instrument. The gas divider shall be checked at the settings typically used and the nominal value shall be compared with the concentration measured by the instrument. The difference shall in each point be within ±1 per cent of the nominal concentration value.

5.3.   Oxygen interference check gases

Oxygen interference check gases consist of a blend of propane, oxygen and nitrogen and shall contain propane at a concentration of 350 ± 75 ppmC1. The concentration shall be determined by gravimetric methods, dynamic blending or the chromatographic analysis of total hydrocarbons plus impurities. The oxygen concentrations of the oxygen interference check gases shall meet the requirements listed in Table A5/3; the remainder of the oxygen interference check gas shall consist of purified nitrogen.

Table A5/3

Oxygen interference check gases

	Engine type	Engine type
	Compression ignition	Positive ignition
O2 concentration	21 ± 1 %	10 ± 1 %
O2 concentration	10 ± 1 %	5 ± 1 %
O2 concentration	5 ± 1 %	0,5 ± 0,5 %

This section will define future requirement for analysers for measuring particle number emissions, once their measurement becomes mandatory.

6.1.   General

The PN analyser shall consist of a pre-conditioning unit and a particle detector that counts with 50 per cent efficiency from approximately 23 nm. It is permissible that the particle detector also pre-conditions the aerosol. The sensitivity of the analysers to shocks, vibration, aging, variability in temperature and air pressure as well as electromagnetic interferences and other impacts related to vehicle and analyser operation shall be limited as far as possible and shall be clearly stated by the equipment manufacturer in its support material. The PN analyser shall only be used within its manufacturer’s declared parameters of operation. An example of a PN analyser setup is provided in Figure A5/1.

Figure A5/1

Example of a PN analyser setup: Dotted lines depict optional parts. EFM = Exhaust mass Flow Meter, d = inner diameter, PND = Particle Number Diluter

Image omitted; see official source

The PN analyser shall be connected to the sampling point via a sampling probe which extracts a sample from the centreline of the tailpipe tube. As specified in paragraph 3.5. of Appendix 4, if particles are not diluted at the tailpipe, the sampling line shall be heated to a minimum temperature of 373 K (100 °C) until the point of first dilution of the PN analyser or the particle detector of the analyser. The residence time in the sampling line shall be less than 3 s.

All parts in contact with the sampled exhaust gas shall be always kept at a temperature that avoids condensation of any compound in the device. This can be achieved for example by heating at a higher temperature and diluting the sample or oxidizing the (semi)volatile species.

The PN analyser shall include a heated section at wall temperature ≥ 573 K. The unit shall control the heated stages to constant nominal operating temperatures, within a tolerance of ± 10 K, and provide an indication of whether or not heated stages are at their correct operating temperatures. Lower temperatures are acceptable as long as the volatile particle removal efficiency fulfils the specifications of paragraph 6.4.

Pressure, temperature and other sensors shall monitor the proper operation of the instrument during operation and trigger a warning or message in case of malfunction.

The delay time of the PN analyser shall be ≤ 5 s.

The PN analyser (and/or particle detector) shall have a rise time of ≤ 3.5 s.

Particle concentration measurements shall be reported normalised to 273 K and 101.3 kPa. If necessary, the pressure and/or temperature at the inlet of the detector shall be measured and reported for the purposes of normalizing the particle concentration.

PN systems that comply with the calibration requirements of UN Regulation No 154 automatically comply with the calibration requirements of this appendix.

6.2.   Efficiency requirements

The complete PN analyser system including the sampling line shall fulfil the efficiency requirements of Table A5/3a.

Table A5/3a

PN analyser (including the sampling line) system efficiency requirements

dp [nm]	Sub-23	23	30	50	70	100	200
E(dp) PN analyser	To be determined	0,2 – 0,6	0,3 – 1,2	0,6 – 1,3	0,7 – 1,3	0,7 – 1,3	0,5 – 2,0

Efficiency E(dp) is defined as the ratio in the readings of the PN analyser system to a reference Condensation Particle Counter (CPC)’s (d50 % = 10 nm or lower, checked for linearity and calibrated with an electrometer) or an Electrometer’s number concentration measuring in parallel monodisperse aerosol of mobility diameter dp and normalized at the same temperature and pressure conditions.

The material should be thermally stable soot-like (e.g. spark discharged graphite or diffusion flame soot with thermal pre-treatment). If the efficiency curve is measured with a different aerosol (e.g. NaCl), the correlation to the soot-like curve must be provided as a chart which compares the efficiencies obtained using both test aerosols. The differences in the counting efficiencies shall be taken into account by adjusting the measured efficiencies based on the provided chart to give soot-like aerosol efficiencies. The correction for multiply charged particles shall be applied and documented but shall not exceed 10 %. These efficiencies refer to the PN analysers with the sampling line. The PN analyser can also be calibrated in parts (i.e. the pre-conditioning unit separately from the particle detector) as long as it is proven that the PN analyser and the sampling line together fulfil the requirements of Table A5/3a. The measured signal from the detector shall be > 2 times the limit of detection (here defined as the zero level plus 3 standard deviations).

6.3.   Linearity requirements

The PN analyser including the sampling line shall fulfil the linearity requirements of paragraph 3.2. of Appendix 5 using monodisperse or polydisperse soot-like particles. The particle size (mobility diameter or count median diameter) shall be larger than 45 nm. The reference instrument shall be an Electrometer or a Condensation Particle Counter (CPC) with d50 = 10 nm or lower, verified for linearity. Alternatively, a particle number system compliant with UN Regulation No 154.

In addition, the differences of the PN analyser from the reference instrument at all points checked (except the zero point) shall be within 15 % of their mean value. At least 5 points equally distributed (plus the zero) shall be checked. The maximum checked concentration shall be >90 % of the PN analyser nominal measurement range.

If the PN analyser is calibrated in parts, then the linearity can be checked only for the PN detector, but the efficiencies of the rest parts and the sampling line shall be considered in the slope calculation.

6.4.   Volatile removal efficiency

The system shall achieve > 99 % removal of ≥ 30 nm tetracontane (CH3(CH2)38CH3) particles with an inlet concentration of ≥ 10000 particles per cubic-centimetre at the minimum dilution.

The system shall also achieve a > 99 % removal efficiency of tetracontane with count median diameter > 50 nm and mass > 1 mg/m³.

The volatile removal efficiency with tetracontane shall be proven only once for the instrument family. The instrument manufacturer though shall provide the maintenance or replacement interval that ensures that the removal efficiency does not drop below the technical requirements. If such information is not provided, the volatile removal efficiency shall be checked yearly for each instrument.

7.1.   General

Instruments or signals for measuring the exhaust mass flow rate shall have a measuring range and response time appropriate for the accuracy required to measure the exhaust mass flow rate under transient and steady state conditions. The sensitivity of instruments and signals to shocks, vibration, aging, variability in temperature, ambient air pressure, electromagnetic interferences and other impacts related to vehicle and instrument operation shall be on a level as to eliminate additional errors.

7.2.   Instrument specifications

The exhaust mass flow rate shall be determined by a direct measurement method applied in either of the following instruments:

- (a) Pitot-based flow devices;

• (b) Pressure differential devices like flow nozzle (details see ISO 5167);

- (c) Ultrasonic flow meter;

• (d) Vortex flow meter.

Each individual exhaust mass flow meter shall fulfil the linearity requirements set out in paragraph 3. Furthermore, the instrument manufacturer shall demonstrate the compliance of each type of exhaust mass flow meter with the specifications in paragraphs 7.2.3. to 7.2.9.

It is permissible to calculate the exhaust mass flow rate based on air flow and fuel flow measurements obtained from sensors with traceable calibration if these fulfil the linearity requirements of paragraph 3., the accuracy requirements of paragraph 8. and if the resulting exhaust mass flow rate is validated according to paragraph 4. of Appendix 6.

In addition, other methods that determine the exhaust mass flow rate based on non-traceable instruments and signals, such as simplified exhaust mass flow meters or ECU signals, are permissible if the resulting exhaust mass flow rate fulfils the linearity requirements of paragraph 3. and is validated according to paragraph 4. of Appendix 6.

7.2.1.   Calibration and verification standards

The measurement performance of exhaust mass flow meters shall be verified with air or exhaust gas against a traceable standard such as a calibrated exhaust mass flow meter or a full flow dilution tunnel.

7.2.2.   Frequency of verification

The compliance of exhaust mass flow meters with paragraphs 7.2.3. to 7.2.9. shall be verified no longer than one year before the actual test.

7.2.3.   Accuracy

The accuracy of the EFM, defined as the deviation of the EFM reading from the reference flow value, shall not exceed ± 3 percent of the reading, or 0.3 % of full scale, whichever is larger.

7.2.4.   Precision

The precision, defined as 2.5 times the standard deviation of 10 repetitive responses to a given nominal flow, approximately in the middle of the calibration range, shall not exceed 1 per cent of the maximum flow at which the EFM has been calibrated.

7.2.5.   Noise

The noise shall not exceed 2 per cent of the maximum calibrated flow value. Each of the 10 measurement periods shall be interspersed with an interval of 30 seconds in which the EFM is exposed to the maximum calibrated flow.

7.2.6.   Zero response drift

The zero response drift is defined as the mean response to zero flow during a time interval of at least 30 seconds. The zero response drift can be verified based on the reported primary signals, e.g., pressure. The drift of the primary signals over a period of 4 hours shall be less than ±2 per cent of the maximum value of the primary signal recorded at the flow at which the EFM was calibrated.

7.2.7.   Span response drift

The span response drift is defined as the mean response to a span flow during a time interval of at least 30 seconds. The span response drift can be verified based on the reported primary signals, e.g., pressure. The drift of the primary signals over a period of 4 hours shall be less than ± 2 per cent of the maximum value of the primary signal recorded at the flow at which the EFM was calibrated.

7.2.8.   Rise time

The rise time of the exhaust flow instruments and methods should match as far as possible the rise time of the gas analysers as specified in paragraph 4.2.7. but shall not exceed 1 second.

7.2.9.   Response time check

The response time of exhaust mass flow meters shall be determined by applying similar parameters as those applied for the emissions test (i.e., pressure, flow rates, filter settings and all other response time influences). The response time determination shall be done with gas switching directly at the inlet of the exhaust mass flow meter. The gas flow switching shall be done as fast as possible, but in less than 0.1 second is highly recommended. The gas flow rate used for the test shall cause a flow rate change of at least 60 per cent full scale of the exhaust mass flow meter. The gas flow shall be recorded. The delay time is defined as the time from the gas flow switching (t 0) until the response is 10 per cent (t 10) of the final reading. The rise time is defined as the time between 10 per cent and 90 per cent response (t 10 to t 90) of the final reading. The response time (t 90) is defined as the sum of the delay time and the rise time. The exhaust mass flow meter response time (t90) shall be ≤ 3 seconds with a rise time (t 10 to t 90) of ≤ 1 second in accordance with paragraph 7.2.8.

8. SENSORS AND AUXILIARY EQUIPMENT

Any sensor or auxiliary equipment used to determine temperature, atmospheric pressure, ambient humidity, vehicle speed, fuel flow or intake air flow, for example, shall not alter or unduly affect the performance of the vehicle’s engine and exhaust after-treatment system. The accuracy of sensors and auxiliary equipment shall fulfil the requirements of Table A5/4. Compliance with the requirements of Table A5/4 shall be demonstrated at intervals specified by the instrument manufacturer, as required by internal audit procedures or in accordance with ISO 9000.

Table A5/4

Accuracy requirements for measurement parameters

| Measurement parameter | Accuracy |

| --- | --- | | Fuel flow [^E0081] | ± 1 % of reading [^E0082] | | Air flow [^E0083] | ± 2 % of reading | | Vehicle speed [^E0084] | ± 1,0 km/h absolute | | Temperatures ≤ 600 K | ± 2 K absolute | | Temperatures > 600 K | ± 0,4 % of reading in Kelvin | | Ambient pressure | ± 0,2 kPa absolute | | Relative humidity | ± 5 % absolute | | Absolute humidity | ± 10 % of reading or, 1 gH2O/kg dry air, whichever is larger |

Optional to determine exhaust mass flow.

[^E0082]: (²)

The accuracy shall be 0.02 per cent of reading if used to calculate the air and exhaust mass flow rate from the fuel flow according to paragraph 7 of Appendix 7.

[^E0083]: (³)

Optional to determine exhaust mass flow.

This requirement applies to the speed sensor only; if vehicle speed is used to determine parameters like acceleration, the product of speed and positive acceleration, or RPA, the speed signal shall have an accuracy of 0.1 % above 3 km/h and a sampling frequency of 1 Hz. This accuracy requirement can be met by using a wheel rotational speed signal.

Appendix 6

Validation of PEMS and non-traceable exhaust mass flow rate

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, PARAMETERS AND UNITS

a 0	—	y intercept of the regression line
a 1	—	slope of the regression line
r 2	—	coefficient of determination
x	—	actual value of the reference signal
y	—	actual value of the signal under validation

3. VALIDATION PROCEDURE FOR PEMS

3.1.   Frequency of PEMS validation

It is recommended to validate the correct installation of a PEMS on a vehicle via comparison with laboratory installed equipment on a test performed on a chassis dynamometer either before the RDE test or, alternatively, after the completion of the test. For tests performed during type approval, the validation test is required.

3.2.   PEMS validation procedure

3.2.1.   PEMS installation

The PEMS shall be installed and prepared according to the requirements of Appendix 4. The PEMS installation shall be kept unchanged in the time period between the validation and the RDE test.

3.2.2.   Test conditions

The validation test shall be conducted on a chassis dynamometer, as far as possible, under type approval conditions by following the requirements of UN Regulation No 154. 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

The total distance-specific emissions [g/km] measured with laboratory equipment shall be calculated in accordance with UN Regulation No 154. The emissions as measured with the PEMS shall be calculated according to Appendix 7, summed to give the total mass of pollutants [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 evaluated against the requirements specified in paragraph 3.3. For the validation of NOX emission measurements, humidity correction shall be applied in accordance with UN Regulation No 154.

3.3.   Permissible tolerances for PEMS validation

The PEMS validation results shall fulfil the requirements given in Table A6/1. If any permissible tolerance is not met, corrective action shall be taken and the PEMS validation shall be repeated.

Table A6/1

Permissible tolerances

| Parameter [Unit] | Permissible absolute tolerance |

| --- | --- | | Distance [km] [^E0085] | 250 m of the laboratory reference | | THC [^E0086] [mg/km] | 15 mg/km or 15 % of the laboratory reference, whichever is larger | | CH4 [^E0085] [mg/km] | 15 mg/km or 15 % of the laboratory reference, whichever is larger | | NMHC [^E0085] [mg/km] | 20 mg/km or 20 % of the laboratory reference, whichever is larger | | PN [^E0085] [#/km] | 8•10¹⁰ p/km or 42 % of the laboratory reference [^E0087] whichever is larger | | CO [^E0085] [mg/km] | 100 mg/km or 15 % of the laboratory reference, whichever is larger | | CO2 [g/km] | 10 g/km or 7,5 % of the laboratory reference, whichever is larger | | NOx [^E0085] [mg/km] | 10 mg/km or 12,5 % of the laboratory reference, whichever is larger |

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.

[^E0086]: (²)

Parameter only mandatory if measurement required for compliance with the limits.

PMP system.

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

4.1.   Frequency of validation

In addition to fulfilling the linearity requirements of paragraph 3. of Appendix 5 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.

4.2.   Validation procedure

The validation shall be conducted on a chassis dynamometer under type approval conditions, as far as applicable on the same vehicle used for the RDE test. As reference, a flow meter with traceable calibration shall be used. The ambient temperature can be any within the range specified in paragraph 5.1. of this Annex. The installation of the exhaust mass flow meter and the execution of the test shall fulfil the requirement of paragraph 3.4.3. of Appendix 4.

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 paragraph 3. of Appendix 7.

- (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: Image omitted; see official source where: y

is the actual value of the signal under validation a 1

is the slope of the regression line x

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 A6/2.

4.3.   Requirements

The linearity requirements given in Table A6/2 shall be fulfilled. If any permissible tolerance is not met, corrective action shall be taken and the validation shall be repeated.

Table A6/2

Linearity requirements of calculated and measured exhaust mass flow

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

Appendix 7

Determination of instantaneous emissions

1. INTRODUCTION

This appendix describes the procedure to determine the instantaneous mass and particle number emissions [g/s; #/s], following application of the data consistency rules of Appendix 4. The instantaneous mass and particle number emissions shall then be used for the subsequent evaluation of a RDE trip and the calculation of the intermediate and final emission result as described in Appendix 11.

2. SYMBOLS, PARAMETERS AND UNITS

| | | |

| --- | --- | --- | | α | — | molar hydrogen ratio (H/C) | | β | — | molar carbon ratio (C/C) | | γ | — | molar sulphur ratio (S/C) | | δ | — | molar nitrogen ratio (N/C) | | Δtt,i | — | transformation time t of the analyser [s] | | Δtt,m | — | transformation time t of the exhaust mass flow meter [s] | | ε | — | molar oxygen ratio (O/C) | | ρ e | — | density of the exhaust | | ρ gas | — | density of the exhaust component ‘gas’ | | λ | — | excess air ratio | | λ i | — | instantaneous excess air ratio | | A/F st | — | stoichiometric air-to-fuel ratio [kg/kg] | | c CH4 | — | concentration of methane | | c CO | — | dry CO concentration [%] | | c CO2 | — | dry CO2 concentration [%] | | c dry | — | dry concentration of a pollutant in ppm or per cent volume | | c gas,i | — | instantaneous concentration of the exhaust component ‘gas’ [ppm] | | c HCw | — | wet HC concentration [ppm] | | c HC(w/NMC) | — | HC concentration with CH4 or C2H6 flowing through the NMC [ppmC1] | | c HC(w/oNMC) | — | HC concentration with CH4 or C2H6 bypassing the NMC [ppmC1] | | c i,c | — | time-corrected concentration of component i [ppm] | | c i,r | — | concentration of component i [ppm] in the exhaust | | c NMHC | — | concentration of non-methane hydrocarbons | | c wet | — | wet concentration of a pollutant in ppm or per cent volume | | E E | — | ethane efficiency | | E M | — | methane efficiency | | H a | — | intake air humidity [g water per kg dry air] | | i | — | number of the measurement | | m gas,i | — | mass of the exhaust component ‘gas’ [g/s] | | q maw,i | — | instantaneous intake air mass flow rate [kg/s] | | q m,c | — | time-corrected exhaust mass flow rate [kg/s] | | q mew,i | — | instantaneous exhaust mass flow rate [kg/s] | | q mf,i | — | instantaneous fuel mass flow rate [kg/s] | | q m,r | — | raw exhaust mass flow rate [kg/s] | | r | — | cross-correlation coefficient | | r² | — | coefficient of determination | | r h | — | hydrocarbon response factor | | u gas | — | u value of the exhaust component ‘gas’ |

For the correct calculation of distance-specific emissions, the recorded traces of component concentrations, exhaust mass flow rate, vehicle speed, and other vehicle data shall be time corrected. To facilitate the time correction, data which are subject to time alignment shall be recorded either in a single data recording device or with a synchronised timestamp following paragraph 5.1. of Appendix 4. The time correction and alignment of parameters shall be carried out by following the sequence described in paragraphs 3.1. to 3.3.

3.1.   Time correction of component concentrations

The recorded traces of all component concentrations shall be time corrected by reverse shifting according to the transformation times of the respective analysers. The transformation time of analysers shall be determined according to paragraph 4.4. of Appendix 5.:

Image omitted; see official source

where:

c i,c		is the time-corrected concentration of component i as function of time t
c i,r		is the raw concentration of component i as function of time t
Δtt,i		is the transformation time t of the analyser measuring component i

3.2.   Time correction of exhaust mass flow rate

The exhaust mass flow rate measured with an exhaust flow meter shall be time corrected by reverse shifting according to the transformation time of the exhaust mass flow meter. The transformation time of the mass flow meter shall be determined according to paragraph 4.4. of Appendix 5.:

Image omitted; see official source

where:

q m,c		is the time-corrected exhaust mass flow rate as function of time t
q m,r		is the raw exhaust mass flow rate as function of time t
Δtt,m		is the transformation time t of the exhaust mass flow meter

In case the exhaust mass flow rate is determined by ECU data or a sensor, an additional transformation time shall be considered and obtained by cross-correlation between the calculated exhaust mass flow rate and the exhaust mass flow rate measured following paragraph 4. of Appendix 6.

3.3.   Time alignment of vehicle data

Other data obtained from a sensor or the ECU shall be time-aligned by cross-correlation with suitable emission data (e.g., component concentrations).

3.3.1.   Vehicle speed from different sources

To time align vehicle speed with the exhaust mass flow rate, it is first necessary to establish one valid speed trace. In case vehicle speed is obtained from multiple sources (e.g., the GNSS, a sensor or the ECU), the speed values shall be time aligned by cross-correlation.

3.3.2.   Vehicle speed with exhaust mass flow rate

Vehicle speed shall be time aligned with the exhaust mass flow rate by cross-correlation between the exhaust mass flow rate and the product of vehicle speed and positive acceleration.

3.3.3.   Further signals

The time alignment of signals whose values change slowly and within a small value range, e.g. ambient temperature, can be omitted.

Any instantaneous emissions or exhaust flow measurements obtained while the combustion engine is deactivated shall be recorded in the data exchange file.

5.1.   Drift correction

Image omitted; see official source

cref,z		is the reference concentration of the zero gas (usually zero) [ppm]
cref,s		is the reference concentration of the span gas [ppm]
cpre,z		is the pre-test analyser concentration of the zero gas [ppm]
cpre,s		is the pre-test analyser concentration of the span gas [ppm]
cpost,z		is the post-test analyser concentration of the zero gas [ppm]
cpost,s		is the post-test analyser concentration of the span gas [ppm]
cgas		is the sample gas concentration [ppm]

5.2.   Dry-wet correction

If the emissions are measured on a dry basis, the measured concentrations shall be converted to a wet basis as:

Image omitted; see official source

where:

c wet		is the wet concentration of a pollutant in ppm or per cent volume
c dry		is the dry concentration of a pollutant in ppm or per cent volume
k w		is the dry-wet correction factor

The following equation shall be used to calculate k w:

Image omitted; see official source

where:

Image omitted; see official source

where:

| | | |

| --- | --- | --- | | H a | | is the intake air humidity [g water per kg dry air] | | c CO2 | | is the dry CO2 concentration [%] | | c CO | | is the dry CO concentration [%] | | α | | is the molar hydrogen ratio of the fuel (H/C) |

5.3.   Correction of NOx for ambient humidity and temperature

NOx emissions shall not be corrected for ambient temperature and humidity.

5.4.   Correction of negative emission results

Negative instantaneous results shall not be corrected.

6.1.   Introduction

The components in the raw exhaust shall be measured with the measurement and sampling analysers described in Appendix 5. The raw concentrations of relevant components shall be measured in accordance with Appendix 4. The data shall be time corrected and aligned in accordance with paragraph 3.

6.2.   Calculating NMHC and CH4 concentrations

For methane measurement using a NMC-FID, the calculation of NMHC depends on the calibration gas/method used for the zero/span calibration adjustment. When a FID is used for THC measurement without a NMC, it shall be calibrated with propane/air or propane/N2 in the normal manner. For the calibration of the FID in series with a NMC, the following methods are permitted:

• (a) the calibration gas consisting of propane/air bypasses the NMC;

• (b) the calibration gas consisting of methane/air passes through the NMC.

It is strongly recommended to calibrate the methane FID with methane/air through the NMC.

In method (a), the concentrations of CH4 and NMHC shall be calculated as follows:

Image omitted; see official source

Image omitted; see official source

In method (b), the concentration of CH4 and NMHC shall be calculated as follows:

Image omitted; see official source

Image omitted; see official source

where:

c HC(w/oNMC)		is the HC concentration with CH4 or C2H6 bypassing the NMC [ppmC1]
c HC(w/NMC)		is the HC concentration with CH4 or C2H6 flowing through the NMC [ppmC1]
r h		is the hydrocarbon response factor as determined in paragraph 4.3.3.(b) of Appendix 5
E M		is the methane efficiency as determined in paragraph 4.3.4.(a) of Appendix 5
E E		is the ethane efficiency as determined in paragraph 4.3.4.(b) of Appendix 5

If the methane FID is calibrated through the cutter (method b), then the methane conversion efficiency as determined in paragraph 4.3.4.(a) of Appendix 5 is zero. The density used for calculating the NMHC mass shall be equal to that of total hydrocarbons at 273.15 K and 101.325 kPa and is fuel-dependent.

7.1.   Introduction

The calculation of instantaneous mass emissions according to paragraphs 8. and 9. requires determining the exhaust mass flow rate. The exhaust mass flow rate shall be determined by one of the direct measurement methods specified in paragraph 7.2. of Appendix 5. Alternatively, it is permissible to calculate the exhaust mass flow rate as described in paragraphs 7.2. to 7.4 of this Appendix.

7.2.   Calculation method using air mass flow rate and fuel mass flow rate

The instantaneous exhaust mass flow rate can be calculated from the air mass flow rate and the fuel mass flow rate as follows:

Image omitted; see official source

where:

q mew,i		is the instantaneous exhaust mass flow rate [kg/s]
q maw,i		is the instantaneous intake air mass flow rate [kg/s]
q mf,i		is the instantaneous fuel mass flow rate [kg/s]

If the air mass flow rate and the fuel mass flow rate or the exhaust mass flow rate are determined from ECU recording, the calculated instantaneous exhaust mass flow rate shall meet the linearity requirements specified for the exhaust mass flow rate in paragraph 3. of Appendix 5 and the validation requirements specified in paragraph 4.3. of Appendix 6.

7.3.   Calculation method using air mass flow and air-to-fuel ratio

The instantaneous exhaust mass flow rate can be calculated from the air mass flow rate and the air-to-fuel ratio as follows:

Image omitted; see official source

where:

Image omitted; see official source

Image omitted; see official source

where:

q maw,i		is the instantaneous intake air mass flow rate [kg/s]
A/F st		is the stoichiometric air-to-fuel ratio [kg/kg]
λ i		is the instantaneous excess air ratio
c CO2		is the dry CO2 concentration [%]
c CO		is the dry CO concentration [ppm]
c HCw		is the wet HC concentration [ppm]
α		is the molar hydrogen ratio (H/C)
β		is the molar carbon ratio (C/C)
γ		is the molar sulphur ratio (S/C)
δ		is the molar nitrogen ratio (N/C)
ε		is the molar oxygen ratio (O/C)

Coefficients refer to a fuel Cβ Hα Oε Nδ Sγ with β = 1 for carbon based fuels. The concentration of HC emissions is typically low and may be omitted when calculating λ i.

If the air mass flow rate and air-to-fuel ratio are determined from ECU recording, the calculated instantaneous exhaust mass flow rate shall meet the linearity requirements specified for the exhaust mass flow rate in paragraph 3. of Appendix 5 and the validation requirements specified in paragraph 4.3. of Appendix 6.

7.4.   Calculation method using fuel mass flow and air-to-fuel ratio

The instantaneous exhaust mass flow rate can be calculated from the fuel flow and the air-to-fuel ratio (calculated with A/Fst and λ i according to paragraph 7.3.) as follows:

Image omitted; see official source

Image omitted; see official source

The calculated instantaneous exhaust mass flow rate shall meet the linearity requirements specified for the exhaust gas mass flow rate in paragraph 3. of Appendix 5 and the validation requirements specified in paragraph 4.3. of Appendix 6.

The instantaneous mass emissions [g/s] shall be determined by multiplying the instantaneous concentration of the pollutant under consideration [ppm] with the instantaneous exhaust mass flow rate [kg/s], both corrected and aligned for the transformation time, and the respective u value in Table A7/1. If measured on a dry basis, the dry-wet correction according to paragraph 5.1. shall be applied to the instantaneous component concentrations before executing any further calculations. If occurring, negative instantaneous emission values shall enter all subsequent data evaluations. Parameter values shall enter the calculation of instantaneous emissions [g/s] as reported by the analyser, flow-measuring instrument, sensor or the ECU. The following equation shall be applied:

Image omitted; see official source

where:

m gas,i		is the mass of the exhaust component ‘gas’ [g/s]
u gas		is the ratio of the density of the exhaust component ‘gas’ and the overall density of the exhaust as listed in Table A7/1
c gas,i		is the measured concentration of the exhaust component ‘gas’ in the exhaust [ppm]
q mew,i		is the measured exhaust mass flow rate [kg/s]
gas		is the respective component
i		number of the measurement

Table A7/1

Raw exhaust gas u values depicting the ratio between the densities of exhaust component or pollutant i [kg/m³] and the density of the exhaust gas [kg/m³]

Fuel	ρ e [kg/m3]	Component or pollutant i	Component or pollutant i	Component or pollutant i	Component or pollutant i	Component or pollutant i	Component or pollutant i
Fuel	ρ e [kg/m3]	NOx	CO	HC	CO2	O2	CH4
Fuel	ρ e [kg/m3]	ρ gas [kg/m3]	ρ gas [kg/m3]	ρ gas [kg/m3]	ρ gas [kg/m3]	ρ gas [kg/m3]	ρ gas [kg/m3]
Fuel	ρ e [kg/m3]	2,052	1,249	[^E0090]	1,9630	1,4276	0,715
Fuel	ρ e [kg/m3]	u gas [^E0091], [^E0092]	u gas [^E0091], [^E0092]	u gas [^E0091], [^E0092]	u gas [^E0091], [^E0092]	u gas [^E0091], [^E0092]	u gas [^E0091], [^E0092]
Diesel (B0)	1,2893	0,001593	0,000969	0,000480	0,001523	0,001108	0,000555
Diesel (B5)	1,2893	0,001593	0,000969	0,000480	0,001523	0,001108	0,000555
Diesel (B7)	1,2894	0,001593	0,000969	0,000480	0,001523	0,001108	0,000555
Ethanol (ED95)	1,2768	0,001609	0,000980	0,000780	0,001539	0,001119	0,000561
CNG [^E0090]	1,2661	0,001621	0,000987	0,000528  [^E0091]	0,001551	0,001128	0,000565
Propane	1,2805	0,001603	0,000976	0,000512	0,001533	0,001115	0,000559
Butane	1,2832	0,001600	0,000974	0,000505	0,001530	0,001113	0,000558
LPG [^E0092]	1,2811	0,001602	0,000976	0,000510	0,001533	0,001115	0,000559
Petrol (E0)	1,2910	0,001591	0,000968	0,000480	0,001521	0,001106	0,000554
Petrol (E5)	1,2897	0,001592	0,000969	0,000480	0,001523	0,001108	0,000555
Petrol (E10)	1,2883	0,001594	0,000970	0,000481	0,001524	0,001109	0,000555
Ethanol (E85)	1,2797	0,001604	0,000977	0,000730	0,001534	0,001116	0,000559

depending on fuel

at λ = 2, dry air, 273 K, 101,3 kPa

u values accurate within 0,2 % for mass composition of: C=66-76 %; H=22-25 %; N=0-12 %

NMHC on the basis of CH2,93 (for THC the u gas coefficient of CH4 shall be used)

u accurate within 0,2 % for mass composition of: C3=70-90 %; C4=10-30 %

ugas is a unitless parameter; the u gas values include unit conversions to ensure that the instantaneous emissions are obtained in the specified physical unit, i.e., g/s

The instantaneous particle number emissions [particles/s] shall be determined by multiplying the instantaneous concentration of the pollutant under consideration [particles/cm³] with the instantaneous exhaust mass flow rate [kg/s], both corrected and aligned for the transformation time and by dividing with the density [kg/m³] according to Table A7/1. If applicable, negative instantaneous emission values shall enter all subsequent data evaluations. All significant digits of preceding results shall enter the calculation of the instantaneous emissions. The following equation shall apply:

Image omitted; see official source

where:

PNi		is the particle number flux [particles/s]
cPN,i		is the measured particle number concentration [#/m3] normalized at 0 °C
qmew,i		is the measured exhaust mass flow rate [kg/s]
ρe		is the density of the exhaust gas [kg/m3] at 0 °C (Table A7/1)

Data Exchange: The data shall be exchanged between the measurement systems and the data evaluation software by a standardised data exchange file provided by the Commission⁶.

Any pre-processing of data (e.g. time correction according to paragraph 3, vehicle speed correction according to paragraph 4.7 of Appendix 4 or the correction of the GNSS vehicle speed signal according to paragraph 6.5. of Appendix 4) shall be done with the control software of the measurement systems and shall be completed before the data exchange file is generated.

Appendix 8

Assessment of overall trip validity using the moving averaging window method

1. INTRODUCTION

The Moving Averaging Window method shall be used to assess the overall trip dynamics. The test is divided in sub-sections (windows) and the subsequent analysis aims at determining whether the trip is valid for RDE purposes. The ‘normality’ of the windows shall be assessed by comparing their CO2 distance-specific emissions with a reference curve obtained from the vehicle CO2 emissions measured in accordance with the WLTP test.

Index (i) refers to the time step

Index (j) refers to the window

Index (k) refers to the category (t=total, ls=low speed, ms=medium speed, hs=high speed) or to the CO2 characteristic curve (cc)

a 1,b 1	-	coefficients of the CO2 characteristic curve
---	---	---
a 2,b 2	-	coefficients of the CO2 characteristic curve
---	---	---
M CO2	-	CO2 mass, [g]
---	---	---
M CO2j	-	CO2 mass in window j, [g]
---	---	---
t i	-	total time in step i, [s]
---	---	---
t t	-	duration of a test, [s]
---	---	---
v i	-	actual vehicle speed in time step i, [km/h]
---	---	---
Image omitted; see official source	-	average vehicle speed in window j, [km/h]
---	---	---
tol 1H	-	upper tolerance for the vehicle CO2 characteristic curve, [%]
---	---	---
tol 1L	-	lower tolerance for the vehicle CO2 characteristic curve, [%]

3.1.   Definition of averaging windows

The instantaneous CO2 emissions calculated according to Appendix 7 shall be integrated using a moving averaging window method, based on a reference CO2 mass.

The usage of the reference CO2 mass is illustrated in Figure A8/2. The principle of the calculation is as follows: The RDE distance-specific CO2 mass emissions are not calculated for the complete data set, but for sub-sets of the complete data set, the length of these sub-sets being determined so as to match always the same fraction of the CO2 mass emitted by the vehicle over the applicable WLTP test (after all appropriate corrections e.g. ATCT are applied, where relevant). The moving window calculations are conducted with a time increment Δt corresponding to the data sampling frequency. These sub-sets used to calculate the vehicle on-road CO2 emissions and its average speed are referred to as ‘averaging windows’ in the following sections. The calculation described in this point shall be run from the first data point (forward), as shown in Figure A8/1.

The following data shall not be considered for the calculation of the CO2 mass, the distance and the vehicle average speed in each averaging window:

The periodic verification of the instruments and/or after the zero drift verifications;