A multimeter is a handheld device used to measure various electrical properties, including voltage (both AC and DC), current, and resistance. Developed in the early 20th century, it has become an essential tool for electricians, engineers, and hobbyists alike. The ability to perform multiple functions with one device makes the multimeter indispensable for troubleshooting and diagnosing electrical issues in circuits.

To check the outlet, the multimeter can measure the voltage to verify it matches the expected level (usually around 120V or 240V, depending on the region). This process helps identify any issues like faulty wiring, poor connections, or power supply problems. Regularly testing outlets with a multimeter can prevent electrical hazards such as shocks or fires. Ensuring proper voltage also guarantees that appliances and devices receive the correct power, promoting their longevity and efficient operation

Items needed: 

1. Multimeter
   
2. Safety Glasses

3. Safety Gloves

Socket overview:

A typical socket has 3 terminals: 

1. Neutral: The neutral wire completes the electrical circuit back to the power source. 
2. L1 (Line 1): This is where the “hot” wire connects. It carries the current from the power source.
3. Ground: Connected to the earth ground, it provides a safety path for stray electricity.

Measuring voltages: 

First, set the multimeter to the volts AC setting (V with the ~ above).

To safely measure the voltage, place one multimeter probe on L1 and the other on Neutral. Always start with the Neutral black probe first before connecting the (Hot) red probe. 

DO NOT insert the hot red wire first because the black probe will become energized and you risk being shocked.

To examine grounding, position one probe on L1 and the other on Ground. A reading similar to that between L1 and Neutral confirms proper wiring.

Minor fluctuations can occur when measuring outlets. On a (rather unique) 277v capacity PDU’s. The PDU may sometimes read a little lower (example shown above).