| PSM 4 | |||
| Component | Symbol | Mole fraction | Uncertainty |
| Carbon monoxide | CO | 1.876 × 10−7 | 0.011 × 10−5 |
| Carbon dioxide | CO2 | 24.978 × 10−2 | 0.535 × 10−5 |
| Total hydrocarbon | CxHy | 1.876 × 10−7 | 0.011 × 10−5 |
| Water | H2O | 1.324 × 10−5 | 0.072 × 10−4 |
| Nitrogen | N2 | 75.020 × 10−2 | 0.786 × 10−5 |
| Oxygen | O2 | 8.120 × 10−6 | 0.038 × 10−4 |