The EPR transmitter is used to provide signal to

• A. The fuel metering control
• B. The engine pressure ratio sensor
• C. The temperature display
• D. The cockpit EPR gauge

Answer: (D)

The signal from the EPR transmitter is used to drive the cockpit EPR gauge. The transmitter converts the engine pressure ratio (the ratio of two pressure signals from the engine, such as compressor discharge pressure and turbine inlet pressure) into an electrical signal that the cockpit instrument displays as EPR. This provides the pilot with a thrust indication used for setting takeoff power and monitoring engine thrust.

Other options aren’t correct because they refer to different systems: fuel metering control is driven by fuel-flow signals, not the EPR gauge signal; the engine pressure ratio sensor is the pressure-sensing element (not the transmitter that sends the gauge signal); and the temperature display is driven by temperature sensors, not by the EPR transmitter.