Abstract: A multi-mode signal measurement system provides at least True RMS and Average RMS signal measurement modes in one system in response to a measurement mode selection made by an operator. The system controls the processing of the input signal by a selected signal measurement unit according to the operator selected signal measurement mode. After signal processing is complete, a display unit displays a value of the measurement of the input signal according to the selected measurement mode. Other measurement modes providing peak value and resistance measurement readings may also be provided.