Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:10:p19
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 10 (pt 19/150)
Character Range: 767112–770178

shall be determined as described in paragraph 8.4.2.3. of Annex 4.
              A.1.3.6. Calculation of the instantaneous PM number emissions

The instantaneous PM number (PNi) emissions (#/s) shall be determined by multiplying the instantaneous concentration of the PM number (#/cm3) with the instantaneous exhaust mass flow rate (kg/s), both corrected and aligned for the transformation time, according to paragraph A.3.1.4.3. of Appendix 3. All negative instantaneous emissions values shall enter subsequent data evaluations as zero. All significant digits of intermediate results shall enter the calculation of the instantaneous emissions. The following formula shall apply for the purposes of determining the instantaneous PM number emissions:
Where:
           PNi  is the instantaneous PM number emissions, #/s

                     cpNi  is the measured PM number concentration, #/m3 normalised at 273 K (0 °C) including internal dilution and particle losses

           qmewi  is the measured exhaust mass flow rate, kg/s

           ρe  is the density of the exhaust gas, kg/m3 at 273 K (0 °C).

A.1.4. Determination of emissions and conformity factors
A.1.4.1. Averaging window principle
The emissions shall be integrated using a moving averaging window method, based on the reference CO2 mass or the reference work. The principle of the calculation is as follows: the 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 the engine CO2 mass or work measured over the reference laboratory transient cycle. The moving average calculations are conducted with a time increment ∆t equal to the data sampling period. These sub-sets used to average the emissions data are referred to as "averaging windows" in the following paragraphs.
Any invalidated data shall not be considered for the calculation of the work or CO2 mass and the emissions of the averaging window.
The following data shall be considered as not valid data:
(a) Zero drift check of the instruments;
(b) The data outside the conditions specified in paragraphs 4.2. and 4.3. of this annex.
              The mass emissions (mg/window) shall be determined as described in paragraph 8.4.2.3. of Annex 4.
       Figure 1
       Vehicle speed versus time and Vehicle averaged emissions, starting from the first averaging window, versus time
              A.1.4.2. Work based method
       Figure 2
       Work based method
           The duration (t2,i – t1,i) of the ith averaging window is determined by:
              Where:
              W(tj,i) is the engine work measured between the start and time tj,i, kWh;
              Wref is the engine work for the WHTC, kWh.
              t2,i  shall be selected such that:
              Where Δt is the data sampling period, equal to 1 second or less.
       A.1.4.2.1. Calculation of the specific emissions

              The specific emissions e (mg/kWh or #/kWh) shall be calculated for each window and each pollutant in the following