🔍 Key Concepts

• diesel engine indicator purpose and what it measures • where on a main propulsion diesel you would tap in to read cylinder pressure over the piston • difference between measuring conditions in the cylinder vs. exhaust, after cooler, or crankcase

💭 Think About

• Ask yourself: to create an indicator diagram of pressure vs. crank angle, where must the indicator sense pressure? • Which of the listed locations is directly exposed to combustion pressure while the engine is firing, without being separated by valves or other components? • Which choices are mainly for gas flow (in or out) or lube oil space, rather than direct combustion pressure?

✅ Before You Answer

• Identify which component has direct access to compression and combustion pressure above the piston. • Eliminate any locations that are normally at much lower pressure than peak firing pressure shown on the gauge scale. • Confirm that the chosen location is one where engines commonly have a dedicated indicator cock/valve provided by the manufacturer.