How to Measure Voltage
Set the multimeter range., Connect the probes to the multimeter., Carefully insert the probes., Read the voltage., Remove the probes.
Step-by-Step Guide
-
Step 1: Set the multimeter range.
Turn the dial to the AC side of the multimeter, then set the potential voltage range to the highest potential voltage you might test.
AC stands for "alternating current." Outlets in the United States use AC voltage, so you'll need to set the multimeter to measure AC voltage when testing an outlet.
This side of the range will usually be labeled with an "AV" or "~V." Standard outlet current is between 110 to 120 volts, but some heavy-duty outlets used for dryers, air conditioners, and other large equipment may have voltage between 220 and 240 volts.
These outlets should be identifiable by their non-standard outlet plugs, however.You should always set the voltage range so that it can measure slightly higher than the expected amount of volts.
If you set the range too low, you may end up overloading and damaging the multimeter. -
Step 2: Connect the probes to the multimeter.
Connect the black probe to the "COM" or "-" port and the red probe to the "V," "mAV," or "+" port.
You'll need to connect the bent banana jack end of each probe to the multimeter.
The straight probe tips will be applied to the outlet.
Some multimeters may have three ports: 10A, COM, and mAV.
Always plug the black probe into the COM port.
Connect the red probe to mAV for low currents up to 200 mA, but connect it to the 10A port for high currents.
For a standard wall outlet, use the low current (mAV) port., Grab both probe tips on the insulated portion beneath the metal pin.
Insert the black probe into one of the straight outlet slots, then insert the red probe into the other.
Only grab the probes by their plastic insulator bases.
Do not touch the metal tip during any part of the process.
After inserting the black probe, slowly release it.
It should remain in the outlet without being held in place.
If it doesn't, try inserting the black probe into the outlet again.
As soon as you insert the red probe, the multimeter should give a voltage reading. , Read the voltage shown on the multimeter.
If using a digital meter, the voltage should show on the display screen.
If using an analog meter, you will need to examine the scale and identify the voltage based on where the needle lands.
In most cases, the scale should read between 108 and 121 volts.
If the voltage is higher or lower than expected, you may need to call a professional electrician to inspect the circuitry and identify any possible problems. , Carefully grip both probes by their insulated bases and pull them straight out of the outlet.
Work carefully.
Do not touch the metal tips with your bare hands and do not allow them to come into contact with one another.
After removing the probes, turn the multimeter knob down to its lowest range and switch the device off. -
Step 3: Carefully insert the probes.
-
Step 4: Read the voltage.
-
Step 5: Remove the probes.
Detailed Guide
Turn the dial to the AC side of the multimeter, then set the potential voltage range to the highest potential voltage you might test.
AC stands for "alternating current." Outlets in the United States use AC voltage, so you'll need to set the multimeter to measure AC voltage when testing an outlet.
This side of the range will usually be labeled with an "AV" or "~V." Standard outlet current is between 110 to 120 volts, but some heavy-duty outlets used for dryers, air conditioners, and other large equipment may have voltage between 220 and 240 volts.
These outlets should be identifiable by their non-standard outlet plugs, however.You should always set the voltage range so that it can measure slightly higher than the expected amount of volts.
If you set the range too low, you may end up overloading and damaging the multimeter.
Connect the black probe to the "COM" or "-" port and the red probe to the "V," "mAV," or "+" port.
You'll need to connect the bent banana jack end of each probe to the multimeter.
The straight probe tips will be applied to the outlet.
Some multimeters may have three ports: 10A, COM, and mAV.
Always plug the black probe into the COM port.
Connect the red probe to mAV for low currents up to 200 mA, but connect it to the 10A port for high currents.
For a standard wall outlet, use the low current (mAV) port., Grab both probe tips on the insulated portion beneath the metal pin.
Insert the black probe into one of the straight outlet slots, then insert the red probe into the other.
Only grab the probes by their plastic insulator bases.
Do not touch the metal tip during any part of the process.
After inserting the black probe, slowly release it.
It should remain in the outlet without being held in place.
If it doesn't, try inserting the black probe into the outlet again.
As soon as you insert the red probe, the multimeter should give a voltage reading. , Read the voltage shown on the multimeter.
If using a digital meter, the voltage should show on the display screen.
If using an analog meter, you will need to examine the scale and identify the voltage based on where the needle lands.
In most cases, the scale should read between 108 and 121 volts.
If the voltage is higher or lower than expected, you may need to call a professional electrician to inspect the circuitry and identify any possible problems. , Carefully grip both probes by their insulated bases and pull them straight out of the outlet.
Work carefully.
Do not touch the metal tips with your bare hands and do not allow them to come into contact with one another.
After removing the probes, turn the multimeter knob down to its lowest range and switch the device off.
About the Author
Kyle Castillo
Brings years of experience writing about DIY projects and related subjects.
Rate This Guide
How helpful was this guide? Click to rate: