Measurement of Indicated Mean Effective Pressure (IMEP) State whether the following is correct: “The indicated mean effective pressure of an engine is obtained from the indicator diagram drawn with the help of an engine indicator.”

Introduction / Context:
Indicated mean effective pressure (IMEP) is a load-normalized measure of the work produced inside the cylinder per cycle. It is derived from the pressure–volume history and is central for comparing engines regardless of displacement.

Given Data / Assumptions:

• A mechanical or electronic engine indicator records pressure vs. crank angle.
• The resulting indicator diagram is converted to a P–V curve over a cycle.
• Cycle averaging yields indicated work per cycle.

Concept / Approach:

IMEP is defined as indicated work per cycle divided by displacement volume per cycle. Since indicated work is the area enclosed by the P–V loop, it must be obtained from an indicator diagram (or an equivalent in-cylinder pressure measurement). Traditional mechanical indicators or modern piezoelectric transducers both serve this purpose.

Step-by-Step Solution:

Verification / Alternative check:

Dynamometer-only tests cannot provide IMEP directly; they provide brake power. IMEP requires cylinder pressure data or a validated combustion model tied to it.

Why Other Options Are Wrong:

Restrictions to two-stroke, supercharged, or full-load operation are unnecessary; IMEP can be obtained for any operating point where a valid indicator diagram is recorded.

Common Pitfalls:

Confusing IMEP (in-cylinder metric) with BMEP (brake MEP). BMEP is derived from brake torque and displacement, while IMEP requires cylinder pressure.

Final Answer:

True