U.S. Code of Federal Regulations
Regulations most recently checked for updates: Dec 13, 2025
This part uses the following abbreviations:
Table 1 to § 1031.200—Abbreviations
| ° | degree |
| % | percent |
| CO | carbon monoxide |
| CO | carbon dioxide |
| EI | emission index |
| g | gram |
| HC | hydrocarbon(s) |
| kg | kilogram |
| kN | kilonewton |
| kW | kilowatt |
| LTO | landing and takeoff |
| m | meter |
| mg | milligram |
| µg | Microgram |
| NO | oxides of nitrogen |
| Num | number |
| nvPM | non-volatile particulate matter |
| nvPM | non-volatile particulate matter mass |
| nvPM | non-volatile particulate matter number |
| nvPM | non-volatile particulate matter mass concentration |
| rO | rated output |
| rPR | rated pressure ratio |
| SN | smoke number |
