The Fluke 1587 digital insulation multimeter (also known as a multitester) is a true RMS, auto- and manual-ranging meter insulation resistance, current, voltage, and resistance for testing line insulation on motors, generators, cables, and switch gear. The insulation test voltages of 50, 100, 250, 500 and 1000V measure resistance from 0.01 megohms to 2 gigohms. The meter also measures capacitance, frequency, and resistance. Temperature is measured using a K-type thermocouple (included). A diode test detects correct functioning of a circuit's diodes. A low-pass filter provides accurate AC voltage and AC frequency measurements on inverters and variable-frequency motor drives by blocking unwanted voltages. Live circuit detection increases user safety by preventing insulation tests when voltages exceed 30 volts, and auto-discharge