Calculation of the Gaseous Emissions. The finally reported test results shall be derived through the following steps:
Calculation of the Gaseous Emissions. 4.1. Determination of the diluted exhaust gas flow The total diluted exhaust gas flow over the cycle (kg/test) must be calculated from the measurement values over the cycle and the corresponding calibration data of the flow measurement device (V0 for PDP or KV for CFV, as determined in annex 4, appendix 5, paragraph 2.). The following formulae must 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, see annex 4, appendix 7, paragraph 2.3.). For the PDP-CVS system MTOTW = 1.293 * V0 * NP * (pB - p1) * 273 / (101.3 * T) where: MTOTW = mass of the diluted exhaust gas on wet basis over the cycle, kg V0 = volume of gas pumped per revolution under test conditions, m³/rev NP = total revolutions of pump per test pB = atmospheric pressure in the test cell, kPa p1 = pressure depression below atmospheric at pump inlet, kPa T = average temperature of the diluted exhaust gas at pump inlet over the cycle, K For the CFV-CVS system MTOTW = 1.293 * t * Kv * p A / T 0.5 where: MTOTW = mass of the diluted exhaust gas on wet basis over the cycle, kg t = cycle time, s KV = calibration coefficient of the critical flow venturi for standard conditions, pA = absolute pressure at venturi inlet, kPa T = absolute temperature at venturi inlet, K If a system with flow compensation is used (i.e. without heat exchanger), the instantaneous mass emissions must be calculated and integrated over the cycle. In this case, the instantaneous mass of the diluted exhaust gas must be calculated as follows. For the PDP-CVS system: MTOTW,i = 1.293 * V 0 * NP,i * (p B - p1) * 273 / (101.3 @ T) where: MTOTW,i =instantaneous mass of the diluted exhaust gas on wet basis, kg NP,i =total revolutions of pump per time interval For the CFV-CVS system: MTOTW,i = 1.293 * ?ti * KV * pA / T 0.5 where: MTOTW,i =instantaneous mass of the diluted exhaust gas on wet basis, kg ?ti =time interval, s If the total sample mass of particulates (MSAM) and gaseous pollutants exceeds 0.5 per cent of the total CVS flow (MTOTW), the CVS flow must be corrected for MSAM or the particulate sample flow must be returned to the CVS prior to the flow measuring device (PDP or CFV).
