How to Read a Multimeter

A multimeter is a measuring instrument that can calculate multiple electrical properties – and it is an electrician’s best friend. It can measure voltage, resistance, and current. The readings it emits are calculated as volt-ohm-milliammeter or VOM for short. An electrician will find great value with this tool, but in truth this is a tool that every homeowner should have. It can be used for multiple needs, from testing batteries to finding a bad switch that may be draining the household of power and spiking the power bill. Before running out to purchase one, it is important to know how to read one. Here are steps to help you use this tool efficiently.

Preparing the Meter
Before any kind of testing can be done, you need to make sure that its settings are fixed properly so that you get the best output. For voltage (V), make sure the dial on the device is turned in a range based upon what kind of current you are looking for. There are two types: Alternating Current (AC) or Direct Current (DC). For Currents, the dial must be turned to the area notated with A, for the amperes, which is how it is measured. Lastly, to test the resistance, look for the Greek letter Omega (Ω). This represents ohms, which is what resistance is measured in. Once all settings have been adjusted, you are ready to use the multimeter.

Reading an Analog Meter
Analog meters are the kind that have a needle behind a glass window which spikes to indicate results. There are usually three arcs printed behind it and each is a different scale. The scale with the (Ω) symbol will show the results for electrical resistance. DC will read the Direct Current, and AC will read out the Alternate Current. Make sure the dial on the front of the device is set for the voltage scale range you are looking to test for.

Common Troubleshooting Issues
If the needle on the analog meter does not move, this could be a sign your setting is too low. If the needle immediately shoots to the other side and doesn’t move, then you will need to do the opposite and raise the range. Make sure you also disconnect power before measuring resistance to ensure you get the most accurate reading. Additionally, calibrate the ohms on the meter. An electrician will know how to do this.

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