(a) Application. Use a flame-ionization detector (FID) analyzer to measure hydrocarbon concentrations in raw or diluted exhaust for either batch or continuous sampling. Determine hydrocarbon concentrations on a carbon number basis of one, C1. For measuring THC or THCE you must use a FID analyzer. For measuring CH4 you must meet the requirements of paragraph (f) of this section. See subpart I of this part for special provisions that apply to measuring hydrocarbons when testing with oxygenated fuels.
(b) Component requirements. We recommend that you use a FID analyzer that meets the specifications in Table 1 of Sec. 1065.205. Note that your FID-based system for measuring THC, THCE, or CH4 must meet all the verifications for hydrocarbon measurement in subpart D of this part, and it must also meet the linearity verification in Sec. 1065.307.
(c) Heated FID analyzers. For measuring THC or THCE from compression-ignition engines, two-stroke spark-ignition engines, and four-stroke spark-ignition engines at or below 19 kW, you must use heated FID analyzers that maintain all surfaces that are exposed to emissions at a temperature of (191 11) [deg]C.
(d) FID fuel and burner air. Use FID fuel and burner air that meet the specifications of Sec. 1065.750. Do not allow the FID fuel and burner air to mix before entering the FID analyzer to ensure that the FID analyzer operates with a diffusion flame and not a premixed flame.
(e) NMHC and NMOG. For demonstrating compliance with NMHC standards, you may either measure THC and CH4 and determine NMHC as described in Sec. 1065.660(b)(2) or (3), or you may measure THC and determine NMHC mass as described in Sec. 1065.660(b)(1). See 40 CFR 1066.635 for methods to demonstrate compliance with NMOG standards for vehicle testing.
(f) CH4. For reporting CH4 or for demonstrating compliance with CH4 standards, you may use a FID analyzer with a nonmethane cutter as described in Sec. 1065.265 or you may use a GC-FID as described in Sec. 1065.267. Determine CH4 as described in Sec. 1065.660(c). [76 FR 57442, Sept. 15, 2011, as amended at 79 FR 23761, Apr. 28, 2014]