Where are the pressure pickups located for Engine Pressure Ratio (EPR) measurement?

Where are the pressure pickups located for Engine Pressure Ratio (EPR) measurement?

• A. Inlet engine and turbine exhaust
• B. In oil gallery and accessory case
• C. In cabin pressurization duct
• D. In the fuel metering system

Answer: (A)

Engine Pressure Ratio uses two gas-path pressure readings: one taken at the engine inlet before the compressor and one taken at the turbine exhaust after the high-pressure turbine. Pressure pickups are placed in the inlet duct to sense the compressor inlet pressure and in the exhaust path downstream of the turbine to sense the exhaust pressure. The ratio of these two pressures provides a quick indicator of engine thrust. The other options don’t relate to the gas-path pressures used for thrust indication (oil pressure, cabin pressure, or fuel system pressures are separate systems).

Engine Pressure Ratio uses two gas-path pressure readings: one taken at the engine inlet before the compressor and one taken at the turbine exhaust after the high-pressure turbine. Pressure pickups are placed in the inlet duct to sense the compressor inlet pressure and in the exhaust path downstream of the turbine to sense the exhaust pressure. The ratio of these two pressures provides a quick indicator of engine thrust. The other options don’t relate to the gas-path pressures used for thrust indication (oil pressure, cabin pressure, or fuel system pressures are separate systems).