Abstract: A portable test set provides field measurements of trim adjustable parameters for a gas turbine engine. Analog input signals from sensors disposed about the engine are filtered, to reduce electromagnetic interference, conditioned, amplified, converted to digital form and provided to a microprocessor. The microprocessor uses the digital input signals and stored data to calculate values for measured trim parameters and outputs the results to a digital readout for display. Circuitry is also provided to permit the operator of the test set to input known data to the engine and/or aircraft in order to verify performance of cockpit instrumentation. The test set also may be placed in an internal test mode for verification of its proper performance.