Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p10
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 10/30)
Character Range: 548208–551162

0,000553

      Notes:
            —       u values of raw exhaust based on ideal gas properties at λ = 2, dry air, 273 K, 101,3 kPa
            —       u values of dilute exhaust based on ideal gas properties and density of air
            —       u values of CNG accurate within 0,2 % for mass composition of: C = 66 – 76 %; H = 22 – 25 %; N = 0 – 12 %
            —       u value of CNG for HC corresponds to CH2,93 (for total HC use u value of CH4).

        5.6.  Calculation of the area control values

              For the three control points selected according to section 2.7.6, the NOx emission shall be measured and calculated according to section 5.6.1 and also determined by interpolation from the modes of the test cycle closest to the respective control point according to section 5.6.2. The measured values are then compared to the interpolated values according to section 5.6.3.

        5.6.1. Calculation of the Specific Emission

              The NOx emission for each of the control points (Z) shall be calculated as follows:

        5.6.2. Determination of the Emission Value from the Test Cycle

              The NOx emission for each of the control points shall be interpolated from the four closest modes of the test cycle that envelop the selected control point Z as shown in Figure 4. For these modes (R, S, T, U), the following definitions apply:

                 Speed(R) = Speed(T) = nRT

                 Speed(S) = Speed(U) = nSU

                 Per cent load(R) = Per cent load(S)

                 Per cent load(T) = Per cent load(U)

              The NOx emission of the selected control point Z shall be calculated as follows:

              and:

              where:

              ER, ES, ET, EU = specific NOx emission of the enveloping modes calculated in accordance with section 5.6.1.

              MR, MS, MT, MU = engine torque of the enveloping modes.

Figure 4

Interpolation of NOx Control Point

        5.6.1. Comparison of NOx Emission Values

              The measured specific NOx emission of the control point Z (NOx,Z) is compared to the interpolated value (EZ) as follows:

        6.   CALCULATION OF THE PARTICULATE EMISSIONS

        6.1.  Data Evaluation

              For the evaluation of the particulates, the total sample masses (msep) through the filter shall be recorded for each mode.

              The filter shall be returned to the weighing chamber and conditioned for at least one hour, but not more than 80 hours, and then weighed. The gross weight of the filters shall be recorded and the tare weight (see section 2.1) subtracted, which results in the par- ticulate sample mass mf.

              If background correction is to be applied, the dilution air mass (md) through the filter and the particulate mass (mf,d) shall be recorded. If more than one measurement was made, the quotient mf,d/md shall be calculated for each single measurement and