In a typical engine pressure ratio indicating system, the indicator is a dual-synchro instrument. The system shows a constant reading of engine performance. This is done by computing the ratio between the gas generator discharge pressure and the inlet pressure of the engine. These ratios are then transmitted to an indicator (both indicators if a two-engine aircraft). Sample pressures are taken from engine gas producer or gas generator ports and from the pilot pressure system. The system includes a transducer. The transducer includes a mounting bracket and a transmitter unit. The transmitter unit contains a multicell, diaphram-actuated computer; gear train; two-phase motor; and transmitting synchros. The indicators are graduated from 1.0 to 2.5 EPR units with 0.1 EPR markings and a vernier dial graduated in 0.01 EPR markings. An adjustable pointer on the face of the indicator is set to the maximum EPR for the ambient temperature to indicate possible engine overspeed. The maximum EPR for given temperatures is listed on the instrument panel. The AC Power system supplies electrical power through the EPR circuit breaker.