IMEP derived from indicator-card area - the fundamental input for cylinder-balance and performance-trend checks.
Formula
$$ IMEP = \frac{\text{Card area}}{\text{Card length}} \cdot \text{Spring scale} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $Card area$ | Planimetered area of indicator diagram | mm² | planimeter / digital reading |
| $Card length$ | Horizontal length of one cycle | mm | ruler |
| $Spring scale$ | Pressure per mm of card height | bar/mm | indicator spring |
| $IMEP$ | Indicated MEP | bar | result |
Sources
- Pounder’s Marine Diesel Engines Ch.3.