These AC Voltmeters are capable of measuring AC voltages of 10 Hz - 500 kHz. The response characteristics of the pointers are of mean-value response. The scales are calibrated with root-mean—square values for sinusoidal waveform inputs.. Range selection of the Dual-pointer Voltmeters (Models AVM23, AVM25, AVM23R,, and AVM25R) can be made with, the two channels directly linked together or with the two channels linked together providing a certain differential level between them, as well as it can be made independently for each of the two channels. Also» these, models of voltmeters are incorporated with a GND MODE selector so that the circuit ground can be connected to or floated from the case ground. Models AVM23R and AVM25R Voltmeters are capable of remote control of range selection.. The remote control signal used for this purpose is a positive-logic TTL-level binary-coded signal with 4 bits per channel. The Remote Controllers which can be used for this purpose are RC01-AVM, RC02-AVM, RCOl-ORC, and RC02-ORC, When the IF01-AVM (GP-IB interface) is used, digital data corresponding to pointer deflection can be sent to the CPU making use of the range selection control signal and DC output signal of the voltmeter. All of the six models of Voltmeters are provided with an AC output terminal which delivers an output signal of approximately CL.1 V rms for full scale. Models AVM23R and AVM25R Voltmeters are provided with a DC output terminal which delivers an output signal of 1 V (±3%) for full scale..