The REED R5055-NIST is an auto-ranging True RMS clamp meter measuring AC/DC current up to 1000A (extendable to 3000A AC with REED's optional flexible probe), AC/DC voltage to 1000V, resistance, capacitance, frequency and contact temperature via a Type K thermocouple input. A 6,000-count backlit display with a 31-segment bargraph, low-pass filter and Low-Z mode help it reject ghost voltages and motor-drive noise, and it's rated CAT III 1000V/CAT IV 600V for tougher industrial panels. The NIST designation means it comes with a traceable calibration certificate documenting the measured data and uncertainties.