Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p25
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 25/56)
Character Range: 366123–369298

mass sampled over the cycle, mg
                  msep  is the mass of diluted exhaust gas passing the particulate collection filters, kg
                  med is the mass of diluted exhaust gas over the cycle, kg
                  With
msep = mset - mssd (64)
 Where:
                  mset  is the mass of double diluted exhaust gas through particulate filter, kg
                  mssd is the mass of secondary diluent, kg
 If the particulate background level of the diluent is determined in accordance with paragraph 7.5.6., the particulate mass may be background corrected. In this case, the particulate mass (g/test) shall be calculated as follows:
                      (65)
 Where:
                  msep is the mass of diluted exhaust gas passing the particulate collection filters, kg
                  med is the mass of diluted exhaust gas over the cycle, kg
                  msd is the mass of diluent sampled by background particulate sampler, kg
                  mb is the mass of the collected background particulates of the diluent, mg
                  D is the dilution factor as determined in paragraph 8.5.2.3.2.
8.6. General calculations
8.6.1. Drift correction
 With respect to drift verification in paragraph 7.8.4., the corrected concentration value shall be calculated as follows:
 (66)
 Where:
                  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 analyzer concentration of the zero gas, ppm
                  cpre,s is the pre-test analyzer concentration of the span gas, ppm
                  cpost,z is the post-test analyzer concentration of the zero gas, ppm
                  cpost,s is the post-test analyzer concentration of the span gas, ppm
                  cgas is the sample gas concentration, ppm
 Two sets of specific emission results shall be calculated for each component in accordance with paragraph 8.6.3., after any other corrections have been applied. One set shall be calculated using uncorrected concentrations and another set shall be calculated using the concentrations corrected for drift according to equation 66.
               Depending on the measurement system and calculation method used, the uncorrected emissions results shall be calculated with equations 36, 37, 56, 58 or 62, respectively. For calculation of the corrected emissions, cgas in equations 36, 37, 56, 58 or 62, respectively, shall be replaced with ccor of equation 66. If instantaneous concentration values cgas,i are used in the respective equation, the corrected value shall also be applied as instantaneous value ccor,i. In equations 58 and 62, the correction shall be applied to both the measured and the background concentration.

 The comparison shall be made as a percentage of the uncorrected results. The difference between the uncorrected and the corrected brake-specific emission values shall be within ±4 per cent of the uncorrected brake-specific emission values or within ±4 per cent of the respective limit value, whichever is greater. If the drift is greater than 4 per cent,