(f)

Appendix 2 is amended as follows: Section 3 is replaced by the following: ‘3. EMISSIONS TEST RUN At the manufacturers request, a dummy test may be run for conditioning of the engine and exhaust system before the measurement cycle. NG and LPG fuelled engines shall be run-in using the ETC test. The engine shall be run over a minimum of two ETC cycles and until the CO emission measured over one ETC cycle does not exceed by more than 10 % the CO emission measured over the previous ETC cycle. 3.1. Preparation of the sampling filters (if applicable) At least one hour before the test, each filter shall be placed in a partially covered petri dish, which is protected against dust contamination, and placed in a weighing chamber for stabilisation. At the end of the stabilisation period, each filter shall be weighed and the tare weight shall be recorded. The filter shall then be stored in a closed petri dish or sealed filter holder until needed for testing. The filter shall be used within eight hours of its removal from the weighing chamber. The tare weight shall be recorded. 3.2. Installation of the measuring equipment The instrumentation and sample probes shall be installed as required. The tailpipe shall be connected to the full flow dilution system, if used. 3.3. Starting the dilution system and the engine The dilution system and the engine shall be started and warmed up until all temperatures and pressures have stabilised at maximum power according to the recommendation of the manufacturer and good engineering practice. 3.4. Starting the particulate sampling system (diesel engines only) The particulate sampling system shall be started and running on by-pass. The particulate background level of the dilution air may be determined by passing dilution air through the particulate filters. If filtered dilution air is used, one measurement may be done prior to or after the test. If the dilution air is not filtered, measurements at the beginning and at the end of the cycle may be done and the values averaged. The dilution system and the engine shall be started and warmed up until all temperatures and pressures have stabilised according to the recommendation of the manufacturer and good engineering practice. In case of periodic regeneration aftertreatment, the regeneration shall not occur during the warm-up of the engine. 3.5. Adjustment of the dilution system The flow rates of the dilution system (full flow or partial flow) shall be set to eliminate water condensation in the system, and to obtain a maximum filter face temperature of 325 K (52 °C) or less (see section 2.3.1 of Annex V, DT). 3.6. Checking the analysers The emission analysers shall be set at zero and spanned. If sample bags are used, they shall be evacuated. 3.7. Engine starting procedure The stabilised engine shall be started according to the manufacturer's recommended starting procedure in the owner's manual, using either a production starter motor or the dynamometer. Optionally, the test may start directly from the engine preconditioning phase without shutting the engine off, when the engine has reached the idle speed. 3.8. Test cycle 3.8.1. Test sequence The test sequence shall be started, if the engine has reached idle speed. The test shall be performed according to the reference cycle as set out in section 2 of this Appendix. Engine speed and torque command set points shall be issued at 5 Hz (10 Hz recommended) or greater. Feedback engine speed and torque shall be recorded at least once every second during the test cycle, and the signals may be electronically filtered. 3.8.2. Gaseous emissions measurement 3.8.2.1. Full flow dilution system At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the measuring equipment shall be started, simultaneously: HC and NOx shall be measured continuously in the dilution tunnel with a frequency of 2 Hz. The average concentrations shall be determined by integrating the analyzer signals over the test cycle. The system response time shall be no greater than 20 s, and shall be coordinated with CVS flow fluctuations and sampling time/test cycle offsets, if necessary. CO, CO2, NMHC and CH4 shall be determined by integration or by analysing the concentrations in the sample bag, collected over the cycle. The concentrations of the gaseous pollutants in the dilution air shall be determined by integration or by collecting into the background bag. All other values shall be recorded with a minimum of one measurement per second (1 Hz). 3.8.2.2. Raw exhaust measurement At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the measuring equipment shall be started, simultaneously: For the evaluation of the gaseous emissions, the emission concentrations (HC, CO and NOx) and the exhaust gas mass flow rate shall be recorded and stored with at least 2 Hz on a computer system. The system response time shall be no greater than 10 s. All other data may be recorded with a sample rate of at least 1 Hz. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation. For calculation of the mass emission of the gaseous components the traces of the recorded concentrations and the trace of the exhaust gas mass flow rate shall be time aligned by the transformation time as defined in section 2 of Annex I. Therefore, the response time of each gaseous emissions analyser and of the exhaust gas mass flow system shall be determined according to the provisions of section 4.2.1 and section 1.5 of Appendix 5 to this Annex and recorded. 3.8.3. Particulate sampling (if applicable) 3.8.3.1. Full flow dilution system At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the particulate sampling system shall be switched from by-pass to collecting particulates. If no flow compensation is used, the sample pump(s) shall be adjusted so that the flow rate through the particulate sample probe or transfer tube is maintained at a value within ± 5 % of the set flow rate. If flow compensation (i.e., proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ± 5 % of its set value (except for the first 10 seconds of sampling). Note: For double dilution operation, sample flow is the net difference between the flow rate through the sample filters and the secondary dilution air flow rate. The average temperature and pressure at the gas meter(s) or flow instrumentation inlet shall be recorded. If the set flow rate cannot be maintained over the complete cycle (within ± 5 %) because of high particulate loading on the filter, the test shall be voided. The test shall be rerun using a lower flow rate and/or a larger diameter filter. 3.8.3.2. Partial flow dilution system At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the particulate sampling system shall be switched from by-pass to collecting particulates. For the control of a partial flow dilution system, a fast system response is required. The transformation time for the system shall be determined by the procedure in section 3.3 of Appendix 5 to Annex III. If the combined transformation time of the exhaust flow measurement (see section 4.2.1) and the partial flow system is less than 0,3 sec, online control may be used. If the transformation time exceeds 0,3 sec, look ahead control based on a pre-recorded test run must be used. In this case, the rise time shall be ≤ 1 sec and the delay time of the combination ≤ 10 sec. The total system response shall be designed as to ensure a representative sample of the particulates, qmp,i, proportional to the exhaust mass flow. To determine the proportionality, a regression analysis of qmp,i versus qmew,i shall be conducted on a minimum 1 Hz data acquisition rate, and the following criteria shall be met: Optionally, a pretest may be run, and the exhaust mass flow signal of the pretest be used for controlling the sample flow into the particulate system (look-ahead control). Such a procedure is required if the transformation time of the particulate system, t50,P or the transformation time of the exhaust mass flow signal, t50,F, or both, are > 0,3 sec. A correct control of the partial dilution system is obtained, if the time trace of qmew,pre of the pretest, which controls qmp, is shifted by a look-ahead time of t50,P + t50,F. For establishing the correlation between qmp,i and qmew,i the data taken during the actual test shall be used, with qmew,i time aligned by t50,F relative to qmp,i (no contribution from t50,P to the time alignment). That is, the time shift between qmew and qmp is the difference in their transformation times that were determined in section 3.3 of Appendix 5 to Annex III. 3.8.4. Engine stalling If the engine stalls anywhere during the test cycle, the engine shall be preconditioned and restarted, and the test repeated. If a malfunction occurs in any of the required test equipment during the test cycle, the test shall be voided. 3.8.5. Operations after test At the completion of the test, the measurement of the diluted exhaust gas volume or raw exhaust gas flow rate, the gas flow into the collecting bags and the particulate sample pump shall be stopped. For an integrating analyser system, sampling shall continue until system response times have elapsed. The concentrations of the collecting bags, if used, shall be analysed as soon as possible and in any case not later than 20 minutes after the end of the test cycle. After the emission test, a zero gas and the same span gas shall be used for re-checking the analysers. The test will be considered acceptable if the difference between the pre-test and post-test results is less than 2 % of the span gas value. 3.9. Verification of the test run 3.9.1. Data shift To minimise the biasing effect of the time lag between the feedback and reference cycle values, the entire engine speed and torque feedback signal sequence may be advanced or delayed in time with respect to the reference speed and torque sequence. If the feedback signals are shifted, both speed and torque must be shifted the same amount in the same direction. 3.9.2. Calculation of the cycle work The actual cycle work Wact (kWh) shall be calculated using each pair of engine feedback speed and torque values recorded. This shall be done after any feedback data shift has occurred, if this option is selected. The actual cycle work Wact is used for comparison to the reference cycle work Wref and for calculating the brake specific emissions (see sections 4.4 and 5.2). The same methodology shall be used for integrating both reference and actual engine power. If values are to be determined between adjacent reference or adjacent measured values, linear interpolation shall be used. In integrating the reference and actual cycle work, all negative torque values shall be set equal to zero and included. If integration is performed at a frequency of less than 5 Hertz, and if, during a given time segment, the torque value changes from positive to negative or negative to positive, the negative portion shall be computed and set equal to zero. The positive portion shall be included in the integrated value. Wact shall be between – 15 % and + 5 % of Wref 3.9.3. Validation statistics of the test cycle Linear regressions of the feedback values on the reference values shall be performed for speed, torque and power. This shall be done after any feedback data shift has occurred, if this option is selected. The method of least squares shall be used, with the best fit equation having the form: y = mx + b where: The standard error of estimate (SE) of y on x and the coefficient of determination (r2) shall be calculated for each regression line. It is recommended that this analysis be performed at 1 Hertz. All negative reference torque values and the associated feedback values shall be deleted from the calculation of cycle torque and power validation statistics. For a test to be considered valid, the criteria of table 7 must be met. Table 7 Regression line tolerances Point deletions from the regression analyses are permitted where noted in Table 8. Table 8 Permitted point deletions from regression analysis start collecting or analysing dilution air, start collecting or analysing diluted exhaust gas, start measuring the amount of diluted exhaust gas (CVS) and the required temperatures and pressures, start recording the feedback data of speed and torque of the dynamometer. start analysing the raw exhaust gas concentrations, start measuring the exhaust gas or intake air and fuel flow rate, start recording the feedback data of speed and torque of the dynamometer. The correlation coefficient R2 of the linear regression between qmp,i and qmew,i shall not be less than 0,95, The standard error of estimate of qmp,i on qmew,i shall not exceed 5 % of qmp maximum, qmp intercept of the regression line shall not exceed ± 2 % of qmp maximum. y | = | Feedback (actual) value of speed (min-1), torque (Nm), or power (kW) m | = | slope of the regression line x | = | reference value of speed (min-1), torque (Nm), or power (kW) b | = | y intercept of the regression line | Speed | Torque | Power Standard error of estimate (SE) of Y on X | Max 100 min–1 | Max 13 % (15 %) (*) of power map maximum engine torque | Max 8 % (15 %) (*) of power map maximum engine power Slope of the regression line, m | 0,95 to 1,03 | 0,83–1,03 | 0,89–1,03 (0,83–1,03) (*) Coefficient of determination, r2 | min 0,9700 (min 0,9500) (*) | min 0,8800 (min 0,7500) (*) | min 0,9100 (min 0,7500) (*) Y intercept of the regression line, b | ± 50 min–1 | ± 20 Nm or ± 2 % (± 20 Nm or ± 3 %) (*) of max torque whichever is greater | ± 4 kW or ± 2 % (± 4 kW or ± 3 %) (*) of max power whichever is greater Conditions | Points to be deleted Full load demand and torque feedback < 95 % torque reference | Torque and/or power Full load demand and speed feedback < 95 % speed reference | Speed and/or power No load, not an idle point, and torque feedback > torque reference | Torque and/or power No load, speed feedback ≤ idle speed + 50 min–1 and torque feedback = manufacturer defined/measured idle torque ± 2 % of max. torque | Speed and/or power No load, speed feedback > idle speed + 50 min–1 and torque feedback > 105 % torque reference | Torque and/or power No load and speed feedback > 105 % speed reference | Speed and/or power’ The following section 4 is inserted: ‘4. CALCULATION OF THE EXHAUST GAS FLOW 4.1. Determination of the diluted exhaust gas flow The total diluted exhaust gas flow over the cycle (kg/test) shall be calculated from the measurement values over the cycle and the corresponding calibration data of the flow measurement device (V 0 for PDP, K V for CFV, C d for SSV), as determined in section 2 of Appendix 5 to Annex III). The following formulae shall be applied, if the temperature of the diluted exhaust is kept constant over the cycle by using a heat exchanger (± 6 K for a PDP-CVS, ± 11 K for a CFV-CVS or ± 11 K for a SSV-CVS), see section 2.3 of Annex V). For the PDP-CVS system: m ed = 1,293 × V 0 × N P × (p b - p 1) × 273 / (101,3 × T) where: For the CFV-CVS system: m ed = 1,293 × t × K v × p p / T 0,5 where: For the SSV-CVS system m ed = 1,293 × QSSV where: Text of image QSSV = A0d2Cdpp √[1 T (rp 1,4286 - rp 1,7143) × (1 1 - rD4rp1,4286)] with: If a system with flow compensation is used (i.e. without heat exchanger), the instantaneous mass emissions shall be calculated and integrated over the cycle. In this case, the instantaneous mass of the diluted exhaust gas shall be calculated as follows. For the PDP-CVS system: m ed,i = 1,293 × V 0 × N P,i × (p b - p 1) × 273 / (101,3 × T) where: N P,i = total revolutions of pump per time interval For the CFV-CVS system: m ed,i = 1,293 × Δt i × K V × p p / T 0,5 where: Δt i = time interval, s For the SSV-CVS system: med = 1,293 × QSSV × Δti where: Δt i = time interval, s The real time calculation shall be initialised with either a reasonable value for C d, such as 0,98, or a reasonable value of Q ssv. If the calculation is initialised with Q ssv, the initial value of Q ssv shall be used to evaluate Re. During all emissions tests, the Reynolds number at the SSV throat must be in the range of Reynolds numbers used to derive the calibration curve developed in section 2.4 of Appendix 5 to this Annex. 4.2. Determination of raw exhaust gas mass flow For calculation of the emissions in the raw exhaust gas and for controlling of a partial flow dilution system, it is necessary to know the exhaust gas mass flow rate. For the determination of the exhaust mass flow rate, either of the methods described in sections 4.2.2 to 4.2.5 may be used. 4.2.1. Response time For the purpose of emissions calculation, the response time of either method described below shall be equal to or less than the requirement for the analyzer response time, as defined in section 1.5 of Appendix 5 to this Annex. For the purpose of controlling of a partial flow dilution system, a faster response is required. For partial flow dilution systems with online control, a response time of ≤ 0,3 seconds is required. For partial flow dilution systems with look ahead control based on a pre-recorded test run, a response time of the exhaust flow measurement system of ≤ 5 seconds with a rise time of ≤ 1 second is required. The system response time shall be specified by the instrument manufacturer. The combined response time requirements for exhaust gas flow and partial flow dilution system are indicated in section 3.8.3.2. 4.2.2. Direct measurement method Direct measurement of the instantaneous exhaust flow may be done by systems such as: Precautions shall be taken to avoid measurement errors which will impact emission value errors. Such precautions include the careful installation of the device in the engine exhaust system according to the instrument manufacturers' recommendations and to good engineering practice. Engine performance and emissions shall especially not be affected by the installation of the device. The accuracy of exhaust flow determination shall be at least ± 2,5 % of reading or ± 1,5 % of engine's maximum value, whichever is the greater. 4.2.3. Air and fuel measurement method This involves measurement of the air flow and the fuel flow. Air flowmeters and fuel flowmeters shall be used that meet the total exhaust flow accuracy requirement of section 4.2.2. The calculation of the exhaust gas flow is as follows: qmew = qmaw + qmf 4.2.4. Tracer measurement method This involves measurement of the concentration of a tracer gas in the exhaust. A known amount of an inert gas (e.g. pure helium) shall be injected into the exhaust gas flow as a tracer. The gas is mixed and diluted by the exhaust gas, but shall not react in the exhaust pipe. The concentration of the gas shall then be measured in the exhaust gas sample. In order to ensure complete mixing of the tracer gas, the exhaust gas sampling probe shall be located at least 1 m or 30 times the diameter of the exhaust pipe, whichever is larger, downstream of the tracer gas injection point. The sampling probe may be located closer to the injection point if complete mixing is verified by comparing the tracer gas concentration with the reference concentration when the tracer gas is injected upstream of the engine. The tracer gas flow rate shall be set so that the tracer gas concentration at engine idle speed after mixing becomes lower than the full scale of the trace gas analyser. The calculation of the exhaust gas flow is as follows: Text of image qmew,i = qvt × ρe 60 × (cmix,i - ca) where: When the background concentration is less than 1 % of the concentration of the tracer gas after mixing (c mix.i) at maximum exhaust flow, the background concentration may be neglected. The total system shall meet the accuracy specifications for the exhaust gas flow, and shall be calibrated according to section 1.7 of Appendix 5 to this Annex. 4.2.5. Air flow and air-to-fuel ratio measurement method This involves exhaust mass calculation from the air flow and the air to fuel ratio. The calculation of the instantaneous exhaust gas mass flow is as follows: Text of image qmew,i = qmaw,i × (1 + 1 A/Fst × λi) with: Text of image A/Fst = 138,0 × (β + α 4 - ε 2 + γ) 12,011 × β + 1,00794 × α + 15,9994 × ε + 14,0067 × δ + 32,065 × γ Text of image λi = β × (100 - cCO × 10–4 2 - cHC × 10–4) + (α 4 × 1 - 2 × cCO × 10–4 3,5 × cCO2 1 + cCO × 10–4 3,5 × cCO2 - ε 2 - δ 2) × (cCO2 + cCO × 10–4) 4,764 × (β + α 4 - ε 2 + γ) × (cCO2 + cCO × 10–4 + cHC × 10–4) where: Note: β can be 1 for fuels containing carbon and 0 for hydrogen fuel. The air flowmeter shall meet the accuracy specifications of section 2.2 of Appendix 4 to this Annex, the CO2 analyser used shall meet the specifications of section 3.3.2 of Appendix 4 to this Annex and the total system shall meet the accuracy specifications for the exhaust gas flow. Optionally, air to fuel ratio measurement equipment such as a zirconia type sensor may be used for the measurement of the excess air ratio which meets the specifications of section 3.3.6 of Appendix 4 to this Annex.’ V 0 | = | volume of gas pumped per revolution under test conditions, m3/rev N P | = | total revolutions of pump per test p b | = | atmospheric pressure in the test cell, kPa p 1 | = | pressure depression below atmospheric at pump inlet, kPa T | = | average temperature of the diluted exhaust gas at pump inlet over the cycle, K t | = | cycle time, s K v | = | calibration coefficient of the critical flow venturi for standard conditions, p p | = | absolute pressure at venturi inlet, kPa T | = | absolute temperature at venturi inlet, K A 0 | = | collection of constants and units conversions Text of image (m3 min) (K1 2 kPa) (1 mm2) = 0,006111 in SI units of d | = | diameter of the SSV throat, m C d | = | discharge coefficient of the SSV p p | = | absolute pressure at venturi inlet, kPa T | = | temperature at the venturi inlet, K r p | = | ratio of the SSV throat to inlet absolute, static pressure = Text of image 1 - ΔP PA rD | = | ratio of the SSV throat diameter, d, to the inlet pipe inner diameter = Text of image d D pressure differential devices, like flow nozzle, ultrasonic flowmeter, vortex flowmeter. q mew,i | = | instantaneous exhaust mass flow, kg/s q vt | = | tracer gas flow, cm3/min c mix.i | = | instantaneous concentration of the tracer gas after mixing, ppm ρ e | = | density of the exhaust gas, kg/m3 (cf. table 3) c a | = | background concentration of the tracer gas in the intake air, ppm A/F st | = | stoichiometric air to fuel ratio, kg/kg λ | = | excess air ratio c CO2 | = | dry CO2 concentration, % c CO | = | dry CO concentration, ppm c HC | = | HC concentration, ppm Sections 4 and 5 are replaced by the following: ‘5. CALCULATION OF THE GASEOUS EMISSIONS 5.1. Data evaluation For the evaluation of the gaseous emissions in the diluted exhaust gas, the emission concentrations (HC, CO and NOx) and the diluted exhaust gas mass flow rate shall be recorded according to section 3.8.2.1 and stored on a computer system. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation. For the evaluation of the gaseous emissions in the raw exhaust gas, the emission concentrations (HC, CO and NOx) and the exhaust gas mass flow rate shall be recorded according to section 3.8.2.2 and stored on a computer system. For analogue analysers the response shall be recorded, and the calibration data may be applied online or offline during the data evaluation. 5.2. Dry/wet correction If the concentration is measured on a dry basis, it shall be converted to a wet basis according to the following formula. For continuous measurement, the conversion shall be applied to each instantaneous measurement before any further calculation. cwet = kW × cdry The conversion equations of section 5.2 of Appendix 1 to this Annex shall apply. 5.3. NOx correction for humidity and temperature As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for ambient air temperature and humidity with the factors given in section 5.3 of Appendix 1 to this Annex. The factors are valid in the range between 0 and 25 g/kg dry air. 5.4. Calculation of the emission mass flow rates The emission mass over the cycle (g/test) shall be calculated as follows depending on the measurement method applied. The measured concentration shall be converted to a wet basis according to section 5.2 of Appendix 1 to this Annex, if not already measured on a wet basis. The respective values for u gas shall be applied that are given in Table 6 of Appendix 1 to this Annex for selected components based on ideal gas properties and the fuels relevant for this Directive. If applicable, the concentration of NMHC and CH4 shall be calculated by either of the methods shown in section 3.3.4 of Appendix 4 to this Annex, as follows: 5.4.1. Determination of the background corrected concentrations (full flow dilution system, only) The average background concentration of the gaseous pollutants in the dilution air shall be subtracted from measured concentrations to get the net concentrations of the pollutants. The average values of the background concentrations can be determined by the sample bag method or by continuous measurement with integration. The following formula shall be used. Text of image c = ce - cd × (1 - 1 D) where: The dilution factor shall be calculated as follows: 5.5. Calculation of the specific emissions The emissions (g/kWh) shall be calculated in the following way: 5.5.1. In case of a periodic exhaust aftertreatment system, the emissions shall be weighted as follows: Text of image MGas = (n1 × MGas,n1 + n2 × MGas,n2) / (n1 + n2) where: 6. CALCULATION OF THE PARTICULATE EMISSION (IF APPLICABLE) 6.1. Data evaluation The particulate filter shall be returned to the weighing chamber no later than one hour after completion of the test. It shall be conditioned in a partially covered petri dish, which is protected against dust contamination, for at least one hour, but not more than 80 hours, and then weighed. The gross weight of the filters shall be recorded and the tare weight subtracted, which results in the particulate sample mass m f. For the evaluation of the particulate concentration, the total sample mass (m sep) through the filters over the test cycle shall be recorded. If background correction is to be applied, the dilution air mass (m d) through the filter and the particulate mass (m f,d) shall be recorded. 6.2. Calculation of the mass flow 6.2.1. Full flow dilution system The particulate mass (g/test) shall be calculated as follows: Text of image mPT = mf msep × med 1000 where: If a double dilution system is used, the mass of the secondary dilution air shall be subtracted from the total mass of the double diluted exhaust gas sampled through the particulate filters. msep = mset – mssd where: If the particulate background level of the dilution air is determined in accordance with section 3.4, the particulate mass may be background corrected. In this case, the particulate mass (g/test) shall be calculated as follows: Text of image mPT = [mf msep - (mf,d md × (1 - 1 D))] × med 1000 where: 6.2.2. Partial flow dilution system The mass of particulates (g/test) shall be calculated by either of the following methods: 6.3. Calculation of the Specific Emission The particulate emission (g/kWh) shall be calculated in the following way: Text of image MPT = mPT Wact where: W act = actual cycle work as determined according to section 3.9.2, kWh. 6.3.1. In case of a periodic regeneration aftertreatment system, the emissions shall be weighted as follows: Text of image PT = (n1 × PTn1 + n2 × PT n2) / (n1 + n2) where: for the raw exhaust gas: Text of image mgas = ugas × Σ i = 1 i = n cgas,i × qmew,i × 1 f where: u gas | = | ratio between density of exhaust component and density of exhaust gas from table 6 c gas,i | = | instantaneous concentration of the respective component in the raw exhaust gas, ppm q mew,i | = | instantaneous exhaust mass flow rate, kg/s f | = | data sampling rate, Hz n | = | number of measurements for the diluted exhaust gas without flow compensation: mgas = ugas × cgas × med where: u gas | = | ratio between density of exhaust component and density of air from table 6 c gas | = | average background corrected concentration of the respective component, ppm m ed | = | total diluted exhaust mass over the cycle, kg for the diluted exhaust gas with flow compensation: Text of image mgas = [ugas × Σ i = 1 i = n (ce,i × qmdew,i × 1 f)] - [(med × cd × (1 - 1/D) × ugas)] where: c e,i | = | instantaneous concentration of the respective component measured in the diluted exhaust gas, ppm c d | = | concentration of the respective component measured in the dilution air, ppm q mdew,i | = | instantaneous diluted exhaust gas mass flow rate, kg/s m ed | = | total mass of diluted exhaust gas over the cycle, kg u gas | = | ratio between density of exhaust component and density of air from table 6 D | = | dilution factor (see section 5.4.1) GC method (full flow dilution system, only): cNMHC = cHC – cCH4 NMC method: Text of image cNMHC = cHC(w/oCutter) × (1 - EM) - cHC (w/Cutter) EE - EM Text of image cCH4 = cHC(w/Cutter) - cHC(w/oCutter) × (1 - EE) EE - EM where: c HC(w/Cutter) | = | HC concentration with the sample gas flowing through the NMC c HC(w/oCutter) | = | HC concentration with the sample gas bypassing the NMC c e | = | concentration of the respective pollutant measured in the diluted exhaust gas, ppm c d | = | concentration of the respective pollutant measured in the dilution air, ppm D | = | dilution factor for diesel and LPG fueled gas engines Text of image D = FS cCO2 + (cHC + cCO) × 10–4 for NG fueled gas engines Text of image D = FS cCO2 + (cNMHC + cCO) × 10–4 where: Concentrations measured on dry basis shall be converted to a wet basis in accordance with section 5.2 of Appendix 1 to this Annex. The stoichiometric factor shall be calculated as follows: Text of image FS = 100 × 1 1 + α 2 + 3,76 × (1 + α 4 - ε 2) where: α, ε are the molar ratios referring to a fuel CH α O ε Alternatively, if the fuel composition is not known, the following stoichiometric factors may be used: c CO2 | = | concentration of CO2 in the diluted exhaust gas, % vol c HC | = | concentration of HC in the diluted exhaust gas, ppm C1 c NMHC | = | concentration of NMHC in the diluted exhaust gas, ppm C1 c CO | = | concentration of CO in the diluted exhaust gas, ppm F S | = | stoichiometric factor F S (diesel) | = | 13,4 F S (LPG) | = | 11,6 F S (NG) | = | 9,5 all components, except NOx: Text of image Mgas = mgas Wact NOx: Text of image Mgas = mgas × kh Wact where: W act = actual cycle work as determined according to section 3.9.2. n1 | = | number of ETC tests between two regenerations n2 | = | number of ETC during a regeneration (minimum of one ETC test) M gas,n2 | = | emissions during a regeneration M gas,n1 | = | emissions after a regeneration. m f | = | particulate mass sampled over the cycle, mg m sep | = | mass of diluted exhaust gas passing the particulate collection filters, kg m ed | = | mass of diluted exhaust gas over the cycle, kg m set | = | mass of double diluted exhaust gas through particulate filter, kg m ssd | = | mass of secondary dilution air, kg mPT, msep, med | = | see above md | = | mass of primary dilution air sampled by background particulate sampler, kg mf,d | = | mass of the collected background particulates of the primary dilution air, mg D | = | dilution factor as determined in section 5.4.1. Text of image mPT = mf msep × medf 1000 where: The total mass of equivalent diluted exhaust gas mass over the cycle shall be determined as follows: Text of image medf = i = n Σ i = 1 qmedf,i × 1 f Text of image qmedf,i = qmew,i × rd,i Text of image rd,i = qmdew,,i (qmdew,,i - qmdw,,i) where: m f | = | particulate mass sampled over the cycle, mg m sep | = | mass of diluted exhaust gas passing the particulate collection filters, kg m edf | = | mass of equivalent diluted exhaust gas over the cycle, kg q medf,i | = | instantaneous equivalent diluted exhaust mass flow rate, kg/s q mew,i | = | instantaneous exhaust mass flow rate, kg/s r d,i | = | instantaneous dilution ratio q mdew,i | = | instantaneous diluted exhaust mass flow rate through dilution tunnel, kg/s q mdw,i | = | instantaneous dilution air mass flow rate, kg/s f | = | data sampling rate, Hz n | = | number of measurements Text of image mPT = mf rs × 1000 where: with: Text of image rs = mse mew × msep msed where: Note: In case of the total sampling type system, m sep and M sed are identical. m f | = | particulate mass sampled over the cycle, mg r s | = | average sample ratio over the test cycle m se | = | sample mass over the cycle, kg m ew | = | total exhaust mass flow over the cycle, kg m sep | = | mass of diluted exhaust gas passing the particulate collection filters, kg m sed | = | mass of diluted exhaust gas passing the dilution tunnel, kg. n1 | = | number of ETC tests between two regeneration events n2 | = | number of ETC tests during a regeneration (minimum of one ETC) Text of image PTn2 | = | emissions during a regeneration Text of image PTn1 | = | emissions outside a regeneration.’

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Source: EUR-Lex (Cellar) · retrieved 2026-11-10 · Text as adopted (Official Journal); later amendments are not incorporated in this text.