The Sinometer BM3548 combines a giga-ohm insulation tester and a digital multimeter seamlessly into one convenient device. As a multimeter, it can be used to measure AC/DC voltage & amperage, resistance, capacitance, frequency, diode test as well as continuity test. As a insulation tester, it can generate up to 1000 volts and test insulation anywhere from 250 KΩ to 40 GΩ. For you convenience and safety, when conducting insulation tester, the display not only shows the resistance, but also the voltage and time duration of the test. Another unique feature of this meter is its self-calibration function, when you enter the calibration mode, you can calibrate all the ranges easily and conveniently by pressing a few buttons.