Digital multimeters can test for many different conditions, such as resistance, amps, and voltage. AC voltage can be checked with a digital multimeter, and the steps vary depending on your type of meter.
You will have either an auto-range or manual range meter. Auto-range multimeters have fewer settings on the dial to choose from. The AC voltage setting may look like V(AC) or V~. The tilde symbol may be used or it may be a picture of a sine wave.
Turn on the multimeter and set it to AC voltage.
Place the black lead to the neutral of the circuit. You can also touch the black lead to a grounded section of the device or circuit, but if possible touch it to neutral.
Place the red lead to the hot wire of a device or circuit.
Read the AC voltage output on the screen of your digital multimeter. The output may vary a little, within a small range of numbers (the reading may fluctuate from 300 to 310 millivolts, for example).
Take regular electrical safety precautions to avoid injury. With a manual range multimeter, set the meter at the highest setting for AC voltage, then move down to smaller ranges until you get a reading. Some meters will give you an overload message if you choose the wrong range. If the device doesn't have an overload warning, it might sustain damage or be destroyed when the wrong range is selected.