Model 1030 Digital RMS Voltmeter utilizes an entirely new type of True Root Mean Square sensing circuit for the accurate measurement of both sinusoidal and non-sinusoidal waveforms. The circuitry was developed to overcome the shortcomings of thermal r. m. s. to d. c. convertors, by directly computing the true r.m.s. value of an input waveform. It offers the user significant advantages over currently available instruments in several important areas of measurement. Among these is its accuracy at extremely low frequencies even with high crest factor signals, its exceptionally rapid response and its accuracy over a wide dynamic range of input signals. The utilization of all-electronic circuitry enables the Model 1030 to operate over a frequency range of 0. 01 Hz to 1 MHz, displaying either the Root Mean Square or the Mean Square value of the input waveform. It opens new fields of measurement capability, in control engineering, noise and vibration studies and in any application involving complex or distorted waveforms. Reading indication is by means of an integrating analogue to digital convertor equipped with highly-efficient cold-cathode seven-segment displays. These are mounted behind a polarizing filter to provide high visual contrast under all normal lighting conditions.