Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p29
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 29/56)
Character Range: 377199–380026

and steady state conditions.
 The electromagnetic compatibility (EMC) of the equipment shall be on a level as to minimize additional errors.
9.3.1.2. Accuracy
 The accuracy, defined as the deviation of the analyzer reading from the reference value, shall not exceed ±2 per cent of the reading or ±0.3 per cent of full scale whichever is larger.
9.3.1.3. Precision
 The precision, defined as 2.5 times the standard deviation of 10 repetitive responses to a given calibration or span gas, shall be no greater than 1 per cent of full scale concentration for each range used above 155 ppm (or ppm C) or 2 per cent of each range used below 155 ppm (or ppm C).
       9.3.1.4. Noise
 The analyzer peak-to-peak response to zero and calibration or span gases over any 10 seconds period shall not exceed 2 per cent of full scale on all ranges used.
9.3.1.5. Zero drift
 The drift of the zero response shall be specified by the instrument manufacturer.
9.3.1.6. Span drift
 The drift of the span response shall be specified by the instrument manufacturer.
9.3.1.7. Rise time
 The rise time of the analyzer installed in the measurement system shall not exceed 2.5 seconds.
9.3.1.8. Gas drying
 Exhaust gases may be measured wet or dry. A gas-drying device, if used, shall have a minimal effect on the composition of the measured gases. Chemical dryers are not an acceptable method of removing water from the sample.
9.3.2. Gas analyzers
9.3.2.1. Introduction
 Paragraphs 9.3.2.2. to 9.2.3.7. describe the measurement principles to be used. A detailed description of the measurement systems is given in Appendix 2 to this annex. The gases to be measured shall be analyzed with the following instruments. For non-linear analyzers, the use of linearizing circuits is permitted.
9.3.2.2. Carbon monoxide (CO) analysis
 The carbon monoxide analyzer shall be of the non-dispersive infrared (NDIR) absorption type.
9.3.2.3. Carbon dioxide (CO2) analysis
 The carbon dioxide analyzer shall be of the non-dispersive infrared (NDIR) absorption type.
9.3.2.4. Hydrocarbon (HC) analysis
 The hydrocarbon analyzer shall be of the heated flame ionization detector (HFID) type with detector, valves, pipework, etc. heated so as to maintain a gas temperature of 463 K ± 10 K (190 ± 10 °C). Optionally, for natural gas fuelled and PI engines, the hydrocarbon analyzer may be of the non-heated flame ionization detector (FID) type depending upon the method used (see Appendix 2 to this annex, paragraph A.2.1.3.).
9.3.2.5. Methane (CH4) and non-methane hydrocarbon (NMHC) analysis
 The determination of the methane and non-methane hydrocarbon fraction shall be performed with a heated non-methane cutter (NMC) and two FIDs as per Appendix 2 to this annex, paragraph A.2.1.4. and paragraph A.2.1.5. The concentration of the components shall be determined as