Modern digital multimeters (DMMs) are user-friendly, accurate, and safe — when used correctly! Reading voltage is simple, but measurements must be properly interpreted. With a clamp-on DMM, accurate ...

The DMM is arguably the most versatile electrical test instrument we have. Even the most basic model can measure voltage, current, and resistance. You can use the resistance measurement function for ...

Measuring the electrical resistance (ohms) of motors, compressors, and other electrical devices in HVAC systems may seem straightforward. But when the measurements of zero (0) or “OL” (overload) come ...

The purpose of a multimeter is to enable you to test electrical circuits and record resistance, voltage and current measurements for future reference. Recording circuit measurements during alarm ...

This multimeter add-on is called the Half Ohm. It allows you to measure small resistance values, and can be used to track down shorts on a PCB. The board acts as a pass-through for both probes. When ...

In the previous article in this series, we looked at bridge circuits used to measure impedance. Now, let's look at some more (simple) math. The scaled bridge voltage and current, v vx and v ix ...