While using a digital multimeter to diagnose electrical problems on customers’ equipment, I frequently hear the comment, “I’ve got one of those multimeter things, but I never learned how to use it.” ...

What Is a Multimeter? A multimeter is a tool that measures electrical properties like resistance, voltage, and current. It is used to test electrical components such as diodes and capacitors.

One of the simplest tasks a digital multimeter can perform is a basic voltage test on a car battery. Positive and negative terminals, hooked up to the car or not, will give a base number.