voltmeter

Battery tester

clamp meter

Grounding resistance meter, voltage tester, phase sequence meter

multimeter

Optical power meter, LAN line tester

Electric meter relay, inverter

clamp meter

Recorder (oscilloscope recorder, storage recorder)

LCR tester

Desktop multimeter

ohmmeter

Recorder, data acquisition device

Impedance Analyzer

Photovoltaic panel, power generation, PV maintenance tester