Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p55
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 55/56)
Character Range: 444806–448397

above equation,
                       = average corrected concentration of particles from the diluted exhaust gas corrected to standard conditions (273.2 K and 101.33 kPa), particles per cubic centimetre,
                       = mean particle concentration reduction factor of the volatile particle remover specific to the dilution settings used for the test.
                 shall be calculated from the following equation:
                        (98)
                  Where:
                             cs,i = a discrete measurement of particle concentration in the diluted gas exhaust from the particle counter, corrected for coincidence and to standard conditions (273.2 K and 101.33 kPa), particles per cubic centimetre,
                             n = number of particle concentration measurements taken over the duration of the test.
                     10.4.4. Test result
              10.4.4.1. Calculation of the specific emissions
              For each individual WHSC, hot WHTC and cold WHTC the specific emissions in number of particles/kWh shall be calculated as follows:
                       (99)
               Where:
                     e = is the number of particles emitted per kWh,
           Wact  = is the actual cycle work according to paragraph 7.8.6., in kWh.

              10.4.4.2. Exhaust after-treatment systems with periodic regeneration
               For engines equipped with periodically regenerating after-treatment systems, the general provisions of paragraph 6.6.2. apply. The WHTC hot start emissions shall be weighted according to equation 5 where  is the average number of particles/kWh without regeneration, and is the average number of particles/kWh with regeneration. The calculation of the regeneration adjustment factors shall be done according to equations 6, 6a, 7 or 8, as appropriate.
              10.4.4.3. Weighted average WHTC test result
               For the WHTC, the final test result shall be a weighted average from cold start and hot start (including periodic regeneration where relevant) tests calculated using one of the following equations:
                  (a)           In the case of multiplicative regeneration adjustment, or engines without periodically regenerating after-treatment
                     (100)
                  (b)           In the case of additive regeneration adjustment
                    (101)
                 Where:
                          Ncold = is the total number of particles emitted over the WHTC cold test cycle,
                          Nhot = is the total number of particles emitted over the WHTC hot test cycle,
                          Wact,cold = is the actual cycle work over the WHTC cold test cycle according to paragraph 7.8.6., in kWh,
                          Wact, hot = is the actual cycle work over the WHTC hot test cycle according to paragraph 7.8.6., in kWh,
                          kr = is the regeneration adjustment, according to paragraph 6.6.2., or in the case of engines without periodically regenerating after-treatment kr = 1
              10.4.4.4. Rounding of final results
               The final WHSC and weighted average WHTC test results shall be rounded in one step to three significant figures in accordance with ASTM E 29–06B. No rounding of intermediate values leading to the final brake specific emission result is permissible.
              10.5. Determination of particle number background
              10.5.1. At the engine manufacturer's request, dilution tunnel background particle number concentrations may be sampled, prior