Digital multimeters (DMM), once called voltmeters, have been described as the tape measure for engineers in the new millennium. With electronics and electrical circuits included in almost every consumer and industrial product, DMMs are a must for designing, testing, and troubleshooting. Here’s a look at the features and capabilities of DMMs, as well as how to use them safely.
DMMs are tools for measuring volts (V), ohms (Ω), and amperes (A). Most DMMs have other features and characteristics, but measuring those three variables are the foundation for all electrical measurements. You should also know the different ways DMMs display their measurements.
Resolution, for instance, refers to how fine a DMM’s measurement is. By knowing the meter’s resolution, you can determine if it is possible for it to see a small change in the measured signal. For example, if the DMM has a resolution of 1 mV on the 4 V range, it can see a change of 1 mV (1/1,000 of a volt) while reading a 1 V signal.