Document ID: chunk:federal_register_of_legislation:F2008C00323:reg:120:p19
Version: federal_register_of_legislation:F2008C00323
Segment Type: reg
Provision Reference: reg 120 (pt 19/23)
Character Range: 288569–291784

density of the pollutant i in grams per litre at normal temperature and pressure (273.2 K and 101.33 kPa),

                   kh = humidity correction factor used for the calculation of the mass emissions of oxides of nitrogen. There is no humidity correction for HC and CO,

                   Ci = concentration of the pollutant i in the diluted exhaust gas expressed in ppm and corrected by the amount of the pollutant i contained in the dilution air,

                   d = distance corresponding to the operating cycle in kilometres.

         1.2. VOLUME DETERMINATION

         1.2.1. Calculation of the volume when a variable dilution device with constant flow control by orifice or venturi is used

         Record continuously the parameters showing the volumetric flow, and calculate the total volume for the duration of the test.

         1.2.2. Calculation of volume when a positive displacement pump is used

         The volume of diluted exhaust gas measured in systems comprising a positive displacement pump is calculated with the following formula:
 V = Vo . N

         where:

               V  = volume of the diluted gas expressed in litres per test (prior to correction),

               Vo = volume of gas delivered by the positive displacement pump in testing conditions in litres per revolution,

               N  = number of revolutions per test.

         1.2.3. Correction of the diluted exhaust-gas volume to standard conditions

         The diluted exhaust-gas volume is corrected by means of the following formula:
                    (2)
         in which:
          (3)
           where:

               PB = barometric pressure in the test room in kPa,

               P1 = vacuum at the inlet to the positive displacement pump in kPa relative to the ambient barometric pressure,

               Tp = average temperature of the diluted exhaust gas entering the positive displacement pump during the test (K).

         1.3. CALCULATION OF THE CORRECTED CONCENTRATION OF POLLUTANTS IN THE SAMPLING BAG

                    (4)

         where:

               Ci = concentration of the pollutant i in the diluted exhaust gas, expressed in ppm and corrected by the amount of i contained in the dilution air,

               Ce = measured concentration of pollutant i in the diluted exhaust gas, expressed in ppm,

               Cd = concentration of pollutant i in the air used for dilution, expressed in ppm,

               DF = dilution factor.

         The dilution factor is calculated as follows:

         For petrol and diesel

   DF =                       13.4     for petrol and diesel  (5a)
   CC02 + (CHC = CC0) . 10-4

   DF =                       11.9     for LPG                (5b)
   CC02 + (CHC = CC0) . 10-4

   DF =                       9.5      for NG                 (5c)
   CC02 + (CHC = CC0) . 10-4

         In these equations:

                   CCO2 = concentration of CO2 in the diluted exhaust gas contained in the sampling bag, expressed in per cent volume,

                   CHC = concentration of HC in the diluted exhaust gas contained in the sampling bag, expressed in ppm carbon equivalent,

                   CCO = concentration