Amprobe ACDC-3400 IND AC/DC CAT IV True-RMS Clamp Meter Digital clamp meter measures alternating current (AC) and direct current (DC) to 1,000 amp, DC voltage to 1,000 volts (V), AC voltage to 750V, capacitance to 6.6 millifarads, resistance to 66 megaohms, frequency to 1 megahertz (MHz), and duty cycles True RMS (root mean square) sensing meter provides accurate readings when measuring linear or non-linear loads, where the current or voltage has a sinusoidal or nonsinusoidal waveform Clamp with a 2" (57 mm) jaw opening measures current without touching or interrupting the circuit Relative zero mode stores a reading in memory to use as a zero point for subsequent readings, allowing quick comparison of multiple readings Meets International Electrotechnical Commission (IEC) safety standard 61010 and is certified for category III installations up to 1,000V and category IV installations up to 600V