Set the voltmeter to the AC voltage closest to the voltage you will measure. The United States, Mexico and Canada generally use 110/120 volt electrical outlets for electrical household appliances and equipment such as lamps, computers, televisions and power tools. Some electrical outlets use 220/240 volts for large equipment and appliances, such as stoves and dryers. 220/240 circuits are easily identified by their non-standard plug configuration. Most European countries and countries in other parts of the world generally use 220/240 volt electrical outlets.
Hold the insulated portion of the probes. Place one probe into each terminal, being careful not to touch the metal parts of the probes together or to anything else.
Read the meter scale or display.
Remove the probes from each of the two terminals, being careful not to touch the metal part of the probes to each other or to anything else.
Call a professional electrical service if the voltage reading is not within the typical range of the particular electrical circuit. For a 120 volt wall outlet in the United States, the normal range would be 108 to 121 volts. In this example, a professional should be called in the voltage measures less than 108 volts or more than 121 volts.
Things You Will Need
- Voltmeter or multimeter
- Positive input terminals are generally red or designated by "(+)," while negative input terminals are generally black or designated by "(-)". However, when checking the AC voltage of an electrical outlet, it does not matter which colored probe is inserted into which terminal.