... IN/LO comparator functionGPIB and RS-232 interfaces for convenient system communication,Calibration performed without opening the cover10 sets of measurement ... voltage, AC voltage, DC current, AC current,2-wire resistance, 4-wire resistance, frequency, period, continuity, diodeMathematic functionmX+b, %, dB, ... please refer to the operation manual for other details. VA82 5 1/2 Digital bench multimeter