Table 3 Uncertainty of different measuring parameters.
(a) Instrument accuracy and measurement uncertainty | ||
|---|---|---|
Parameter | Accuracy | Uncertainty (%) |
Fuel flow rate | ± 0.5% | ± 0.75 |
Air flow rate | ± 1.0% | ± 1.2 |
Brake power | ± 0.2% | ± 0.5 |
In-cylinder pressure | ± 0.5% | ± 0.7 |
Crank angle | ± 1° CA | ± 1.0 |
Temperature | ± 1 °C | ± 0.8 |
CO | ± 0.03 vol% | ± 0.14 |
NOx | ± 10 ppm | ± 0.7 |
Smoke | ± 0.05 vol% | ± 0.7 |
(b) Derived parameters uncertainty | ||
|---|---|---|
Parameter | Method of calculation | Uncertainty (%) |
BSFC | Based on fuel flow and brake power | ± 0.7 |
BTE | From calorific value and BSFC | ± 0.5 |
