Multimeters: price comparison

The measurement category (CAT) under the IEC/EN 61010 series of standards indicates the environment in which a multimeter may be used safely. CAT II covers measurements on equipment connected via a plug, CAT III the fixed building installation such as distribution boards and socket circuits, and CAT IV the service connection. Together with the voltage rating (for example CAT III 600 V), it describes how well the device is protected against voltage spikes.

Very cheap multimeters often carry impressive markings but are not always tested to these standards. For batteries, a car's electrical system and electronics tinkering, that's of secondary importance. If you measure on 230 V circuits, look for a device with a credible CAT III rating, fused current ranges and good test leads.

Which features you need depends on what you want to measure:

For occasional measurements on batteries, power supplies and in the car, a simple device with continuity tester and auto-range is enough. For electronics and off-grid solar systems, True RMS, higher resolution and DC current measurement up to 10 A are worthwhile. If you work on domestic installations professionally, choose branded devices with verifiable safety certification.

Important: a multimeter is no substitute for a two-pole voltage tester when you need to verify that a circuit is dead before working on the electrical installation. That kind of work belongs in the hands of a qualified electrician anyway.

Good test leads with finger guards, a matching CAT rating and shrouded probe tips are just as important as the device itself. Check them for damage before every measurement. Crocodile clips, temperature probes and a carrying case make everyday work in the workshop and car easier.