Section 1065.265 - Nonmethane cutter(a)Application. You may use a nonmethane cutter to measure CH4 with a FID analyzer. A nonmethane cutter oxidizes all nonmethane hydrocarbons to CO2 and H2O. You may use a nonmethane cutter for raw or diluted exhaust for batch or continuous sampling.(b)System performance. Determine nonmethane-cutter performance as described in § 1065.365 and use the results to calculate CH4 or NMHC emissions in § 1065.660 .(c)Configuration. Configure the nonmethane cutter with a bypass line if it is needed for the verification described in § 1065.365 .(d)Optimization. You may optimize a nonmethane cutter to maximize the penetration of CH4 and the oxidation of all other hydrocarbons. You may humidify a sample and you may dilute a sample with purified air or oxygen (O2) upstream of the nonmethane cutter to optimize its performance. You must account for any sample humidification and dilution in emission calculations. 70 FR 40516 , July 13, 2005, as amended at 73 FR 37300 , June 30, 2008; 76 FR 57442 , Sept. 15, 2011