Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p33
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 33/39)
Character Range: 1246264–1249444

paragraph 8.4.1.)

              The exhaust mass flow shall be determined according to the direct measurement method as described in section 8.4.1.3.

              Alternatively the airflow and air to fuel ratio measurement method according to paragraph 8.4.1.6. (equations 30, 31 and 32) may be used only if α, γ, δ and ε values are determined according to  sections A.6.2. and A.6.3. of Appendix 6. The use of a zirconia-type sensor to determine the air fuel ratio is not allowed.

              A.4.4.3.2. Determination of the gaseous components (Annex 4, section 8.4.2.)

              The calculations shall be performed according to Annex 4, section 8. but the ugas-values and molar ratios as described in section A.6.2. and A.6.3. of Appendix 6 shall be used.

              A.4.4.3.3. Particulate determination (Annex 4, section 8.4.3.)

              For the determination of particulate emissions with the partial dilution measurement method the calculation shall be performed according to Annex 4, paragraph 8.4.3.2.

              For controlling the dilution ratio one of the following two methods may be used:

              - The direct mass flow measurement as described in paragraph 8.4.1.3.

                  - The airflow and air to fuel ratio measurement method according to paragraph 8.4.1.6. (equations 30, 31 and 32) may only be used when this is combined with the look ahead method described in  paragraph 8.4.1.2. and if α, γ, δ and ε values are determined according to sections A.6.2. and A.6.3. of Appendix 6.

              The quality check according to paragraph 9.4.6.1. shall be performed for each measurement.

              A.4.4.3.4. Additional requirements regarding the exhaust gas mass flow meter

              The flow meter referred to in sections A.4.4.3.1. and A.4.4.3.3. shall not be sensitive to the changes in exhaust gas composition and density. The small errors of e.g. pitot tube or orifice-type of measurement (equivalent with the square root of the exhaust density) may be neglected.

              A.4.4.4. Full flow dilution measurement (CVS) (Annex 4, section 8.5.)

              The possible variation of the fuel composition will only influence the hydrocarbons measurement results calculation. For all other components the appropriate equations from section 8.5.2. of Annex 4 shall be used.

              The exact equations shall be applied for the calculation of the hydrocarbon emissions using the molar component ratios determined from the fuel consumption measurements of both fuels according to section A.6.4. of Appendix 6.

              A.4.4.4.1. Determination of the background corrected concentrations (Annex 4, paragraph 8.5.2.3.2.)

              To determine the stoïchiometric factor, the molar hydrogen ratio α of the fuel shall be calculated as the average molar hydrogen ratio of the fuel mix during the test according to section A.6.4. of Appendix 6.

              Alternatively the Fs value of the gaseous fuel may be used in equation 59 or 60 of Annex 4.

              A.4.5. Equipment specification and verification (Annex 4, section 9.)

              A.4.5.1. Oxygen interference check gases