Testing an electrical socket with a mulitmeter is the best way to make sure the outlet is functioning properly. A multimeter is a device that measures the voltage and the current of the electricity present in the outlet. Using a multimeter can be challenging, due to the various settings on the device. But you can safely test an electrical socket with a multimeter by following a few basic steps.
Inspect the leads on your multimeter to make sure they are not broken or frayed. If they are damaged, replace them before continuing.
Insert each lead firmly into its socket on your multimeter.
Turn the rotary switch on the multimeter to the AC Voltage, or ACV, section of the selection dial and find the reading that is closest to120 volts.
Insert the black lead into the larger of the two slots on the electrical socket. If it's an older outlet with slots that are the same size, use either slot.
Insert the red lead into the other slot.
Watch the display on your multimeter. If there is electricity in the outlet, the display will show either a positive or negative reading of around 120 volts.
Remove the black lead from the socket, followed by the red lead.
Test the multimeter itself on a GFI circuit, which you will find next to the sink in your bathroom. The GFI will short out and protect you while you learn how to work the mulitmeter. The meter should read around 120 volts, but it probably won't hit that exactly. A negative reading on your multimeter just means that the positive lead is in the outlet's neutral slot. Although reversing the leads will make the reading positive, the numbers will be the same.
Do not attempt this process until you familiarise yourself with the multimeter. Do not attempt this process if the leads are frayed or broken. Be absolutely certain that both leads are firmly inserted in the multimeter before sticking one into an outlet. Attempt this process only in a dry environment. Go slowly and take your time whenever you are working with electricity.