Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:10:p27
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 10 (pt 27/30)
Character Range: 595085–598165

lowest range used.

        3.1.6. Rise time

              The rise time of the analyser installed in the measurement system shall not exceed 3,5 s.

              Note: Only evaluating the response time of the analyser alone will not clearly define the suitability of the total system for transient testing. Volumes and especially dead volumes through out the system will not only effect the transportation time from the probe to the analyser, but also effect the rise time. Also transport times inside of an analyser would be defined as analyser response time, like the converter or water traps inside NOx analysers. The determination of the total system response time is described in sec- tion 1.5 of Appendix 5 to this Annex.

        3.2.  Gas drying

              The optional gas drying device must have a minimal effect on the concentration of the measured gases. Chemical dryers are not an acceptable method of removing water from the sample.

        3.3.  Analysers

              Sections 3.3.1 to 3.3.4 describe the measurement principles to be used. A detailed description of the measurement systems is given in Annex V. The gases to be measured shall be analysed with the following instruments. For non-linear analysers, the use of lin- earising circuits is permitted.

        3.3.1 Carbon monoxide (CO) analysis

              The carbon monoxide analyser shall be of the Non-Dispersive InfraRed (NDIR) absorption type.

        3.3.2. Carbon dioxide (CO2) analysis

              The carbon dioxide analyser shall be of the Non-Dispersive InfraRed (NDIR) absorption type.

        3.3.3. Hydrocarbon (HC) analysis

              For diesel and LPG fuelled gas engines, the hydrocarbon analyser shall be of the Heated Flame Ionisation Detector (HFID) type with detector, valves, pipework, etc. heated so as to maintain a gas temperature of 463 K ± 10 K (190 ± 10 °C). For NG fuelled gas engines, the hydrocarbon analyser may be of the non heated Flame Ionisation Detector (FID) type depending upon the method used (see section 1.3 of Annex V).

        3.3.4. Non-Methane Hydrocarbon (NMHC) analysis (NG fuelled gas engines only)

              Non-methane hydrocarbons shall be determined by either of the following methods:

        3.3.4.1. Gas chromatographic (GC) method

              Non-methane hydrocarbons shall be determined by subtraction of the methane analysed with a Gas Chromatograph (GC) con- ditioned at 423 K (150 °C) from the hydrocarbons measured according to section 3.3.3.

        3.3.4.2. Non-Methane Cutter (NMC) method

              The determination of the non-methane fraction shall be performed with a heated NMC operated in line with an FID as per sec- tion 3.3.3 by subtraction of the methane from the hydrocarbons.

        3.3.5. Oxides of Nitrogen (NOx) analysis

              The oxides of nitrogen analyser shall be of the ChemiLuminescent Detector (CLD) or Heated ChemiLuminescent Detector (HCLD) type with a NO2/NO converter, if measured on a dry basis. If measured on a wet basis, a HCLD with converter maintained above