Follow these steps to check an electrical outlet:
1. Connect the black probe to the common (COM) jack on the multimeter. Plug the red probe into the jack labeled as AC voltage or ohms. It may also be labeled VΩmA, VΩ or V (for voltage).
2. Set the mode on your multimeter to AC voltage (V~). Some multimeters will automatically adjust voltage measurement settings while other meters may require you to choose from a range of high or low voltage settings. When measuring AC for the first time, you want to select the highest setting available on your meter.
3. Place the end of the black probe into one of the vertical outlet slots. Put the red probe into the other vertical outlet slot.
4. Check your reading. In the United States, voltage readings should be 120VAC (± 5 - 10%) for standard wall outlets.
5. When you’re done, remove the red & black probes from the outlet you’re testing.
