Guide for Using a Digital Multimeter

 A digital multimeter can be a very useful tool when working with anything designed to run on electricity.  Knowing how to use the different features of a digital multimeter can be very helpful in analyzing and troubleshooting electronics devices.  From circuit board repair to testing household batteries, digital multimeters have many uses, but different settings are required in order to perform tests properly.  This guide shows the details of using different tests of a digital multimeter.

The digital multimeter can be used to test DC current (Amps). Set the meter dial to the DC current setting as shown above in the photo. Plug the red probe into the red A (Amps) jack. Plug the black probe into the com jack. Measure an in-circuit current by holding the red probe on the positive side of the circuit and holding the black probe to the negative side. For troubleshooting and building electronics projects, the ability to measure current is very important. Make sure to limit measuring of DC current to the maximum amount shown on your meter or in the multimeter manual to avoid damaging the meter.

The digital multimeter can be used to test AC current (Amps). Set the meter dial to the DC current setting as shown above in the photo. Plug the red probe into the red A (Amps) jack. Plug the black probe into the com jack. Measure an in-circuit current by holding the red probe on the positive side of the circuit and holding the black probe to the negative side. For troubleshooting and building electronics projects, the ability to measure current is very important. Make sure to limit measuring of AC current to the maximum amount shown on your meter or in the multimeter manual to avoid damaging the meter.  Never try to measure high current sources with a standard multimeter.

Use your digital multimeter to test DC voltage by using the dial setting shown in the photo above.  DC voltage is any voltage source from a battery or that has passed through a converter like a wall wart or voltage transformer that plugs into a wall.  Measuring DC voltage is typically one of the most used features of the digital multimeter.  Plug the + red probe into the red voltage, Ohm, diode jack. Plug the - black probe into the com jack. Hold the red probe on the positive side of the DC voltage source and hold the black probe to the negative side.  High voltage or current should never be measured with a standard digital multimeter

Use your digital multimeter to measure AC voltage by using the dial setting shown in the photo above.  AC voltage is any voltage source like a wall outlet.  Things like wall warts or voltage transformers that plug into a wall change the power from AC to DC voltage.  Plug the + red probe into the red voltage, Ohm, diode jack. Plug the - black probe into the com jack. Hold the red probe on the positive side of the AC voltage source and hold the black probe to the negative side.  High voltage or current should never be measured with a standard digital multimeter.

One of the most useful tests a digital multimeter can perform is the continuity test.  This is a great tool to test wires, circuit board traces, or fuses.  Position the dial setting as shown in the photo above. Plug the red probe into the red voltage, Ohm, diode jack. Plug the black probe into the com jack. Test circuit boards or wiring by holding one lead to one end of a trace or wire and the other lead to the other side of the lead or wire. The same is true for fuses.  A beep from the multimeter indicates a completed electrical connection.  This means that the trace, wire, or fuse is good.

The resistor test is an often used feature used by most multimeter owners. Resistors are a critical part of any circuit design, but when they no longer work the result can be damaging to other more expensive chips or memory on the circuit. Use a digital multimeter to test resistors by setting the digital multimeter on the setting shown in the photo above. Plug the + red probe into the red voltage, Ohm, diode jack. Plug the - black probe into the com jack. Hold the red probe on the positive side of the resistor in the circuit and hold the black probe to the negative side. If the resistor is tested loose the direction of voltage does not matter.