What symbols, acronyms, and abbreviations does this part use?

The following symbols, acronyms, and abbreviations apply to this part: ABT Averaging, banking, and trading. cc cubic centimeters. CFR Code of Federal Regulations. CH 4 methane. CO carbon monoxide. CO 2 carbon dioxide. EPA Environmental Protection Agency. FEL Family Emission Limit. g gram. HC hydrocarbon. hr hour. kPa kilopascals. kW kilowatts. N 2 O nitrous oxide. NMHC nonmethane hydrocarbons. NO X oxides of nitrogen (NO and NO 2 ). psig pounds per square inch of gauge pressure. RPM revolutions per minute. THC total hydrocarbon. THCE total hydrocarbon equivalent. U.S.C. United States Code.