A multimeter tests continuity. It also can measure the amount of alternating current (AC or household current) or direct current (DC or battery current) in a plugged-in or live circuit. It can check voltage, too. For example, a multimeter can verify that there are about 120 volts in an AC circuit or that a 9-volt battery is fully charged. In addition, a multimeter can check resistance. A continuity tester checks resistance, but answers YES or NO. A multimeter checks resistance and reports how many ohms (the measurement of resistance) a circuit has.

Multimeters are relatively inexpensive. The analog unit shown was $10 and the digital multimeter was $20, though you can pay $50 or more for more accurate models. The ones used in this website are sufficient for most electrical tests.

Analog multimeters measuring conductivity/resistance must first be adjusted for a zero reading. Check instructions that come with a new multimeter.

You can use a multimeter to test motors, switches, controllers, and many other electrical gadgets. Specific instructions will come with the multimeter (also called a volt-ohmmeter or VOM) you purchase.