How Does a Multimeter Work?

Auto Mechanic Using a Digital Multimeter

A multimeter is an instrument used to test electronic circuits to ensure that everything is functioning properly. But, how does a multimeter work? What is a multimeter used to measure? A standard multimeter utilizes probes to test the current, resistance, or voltage of an object. More expensive models can also test capacitance and inductance, but we will focus on the standard multimeter functions in this guide.

What is a Multimeter Used to Measure?

How does a multimeter work? A multimeter actually combines several meters (as the name implies) into one handy tool. An ammeter measures current, an ohmmeter measures resistance, and a voltmeter is used to measure voltage across two points. We will take a closer look at the three main multimeter functions below:


The ammeter function of a multimeter is used to determine the number of electrons passing a given point for a set amount of time (current). Amperes are the unit of measurement, and a multimeter can determine how many amperes an object is drawing. This is a good way to test if an appliance is drawing excess power, which could cause a circuit breaker to open. 


Electrical resistance is measured by the ohmmeter. Electrical resistance is known as the opposition of electric current an object possesses (rubber insulation being highly resistant, copper wires offering little resistance) and is measured in ohms. A short circuit will have a resistance of zero or near zero, while an open circuit has infinite resistance.


A voltmeter measures electrical potential between two points in volts. Multimeters can be used to measure current and voltage in both alternating current (AC) and direct current (DC). This is important as household outlets use AC in the U.S, while batteries operate on DC. The correct mode to the test object must be selected when using your multimeter in order to gain accurate measurements.

Work With Gateway Cable Company

Still unsure of the answer to the question, “what is a multimeter used to measure?” Not to worry, you can contact our team to gain insight into multimeter functionality, learn how to test cables with a multimeter, and much more! If you need reliable equipment for your next project, request a quote from Gateway Cable Company. We are proud to offer high-quality products manufactured here in the U.S.A.