Back-calculate λ = AFR / AFR_stoich from measured exhaust-gas oxygen percentage.
Formula
$$ \lambda \approx \frac{21}{21 - O_2%} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $O_2%$ | Oxygen in dry exhaust | % v/v | portable analyser / CEMS |
| $λ$ | Excess-air factor | - | result |
Sources
- ISO 10396 - Stationary source emissions sampling.