Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p30
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 30/56)
Character Range: 379770–382603

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 per paragraph 8.6.2.
9.3.2.6. Oxides of nitrogen (NOx) analysis
 Two measurement instruments are specified for NOx measurement and either instrument may be used provided it meets the criteria specified in paragraphs 9.3.2.6.1. or 9.3.2.6.2., respectively. For the determination of system equivalency of an alternate measurement procedure in accordance with paragraph 5.1.1., only the CLD is permitted.
9.3.2.6.1. Chemiluminescent detector (CLD)
 If measured on a dry basis, the oxides of nitrogen analyzer shall be of the chemiluminescent detector (CLD) or heated chemiluminescent detector (HCLD) type with a NO2/NO converter. If measured on a wet basis, a HCLD with converter maintained above 328 K (55 °C) shall be used, provided the water quench check (see paragraph 9.3.9.2.2.) is satisfied. For both CLD and HCLD, the sampling path shall be maintained at a wall temperature of 328 K to 473 K (55 °C to 200 °C) up to the converter for dry measurement and up to the analyzer for wet measurement.
9.3.2.6.2. Non-dispersive ultraviolet detector (NDUV)
 A non-dispersive ultraviolet (NDUV) analyzer shall be used to measure NOx concentration. If the NDUV analyzer measures only NO, a NO2/NO converter shall be placed upstream of the NDUV analyzer. The NDUV temperature shall be maintained to prevent aqueous condensation, unless a sample dryer is installed upstream of the NO2/NO converter, if used, or upstream of the analyzer.
9.3.2.7. Air to fuel measurement
 The air to fuel measurement equipment used to determine the exhaust gas flow as specified in paragraph 8.4.1.6. shall be a wide range air to fuel ratio sensor or lambda sensor of Zirconia type. The sensor shall be mounted directly on the exhaust pipe where the exhaust gas temperature is high enough to eliminate water condensation.
 The accuracy of the sensor with incorporated electronics shall be within:
 3 per cent of reading for   < 2
 5 per cent of reading for 2   < 5
 10 per cent of reading for 5  
 To fulfil the accuracy specified above, the sensor shall be calibrated as specified by the instrument manufacturer.
9.3.3. Gases
 The shelf life of all gases shall be respected.
9.3.3.1. Pure gases
 The required purity of the gases is defined by the contamination limits given below. The following gases shall be available for operation:
a) For raw exhaust gas
                   Purified nitrogen
 (Contamination  1 ppm C1,  1 ppm CO,   400 ppm CO2,
 0.1 ppm NO)
                   Purified oxygen
                  (Purity  99.5 per cent vol O2)

                   Hydrogen-helium mixture