{"data":{"id":"us/40-cfr-1065.265","jurisdiction":"us","citation":"40 CFR 1065.265","heading":"Nonmethane cutter.","body":"(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.\n(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.\n(c) Configuration. Configure the nonmethane cutter with a bypass line if it is needed for the verification described in § 1065.365.\n(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.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER U—AIR POLLUTION CONTROLS","PART 1065—ENGINE-TESTING PROCEDURES","Subpart C—Measurement Instruments"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"84c3ecc6222d28f31acc4a36dc9861e5c6c2b9c5fd03b2a7a84c1c207fb67260","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-1065.260","next":"us/40-cfr-1065.266"},"notice":"GroundRules: Original legal text. Not legal advice."}