Compare three things: the measurement category, the fuse, and whether it is true-RMS. Everything else on a multimeter listing is a function list.
The measurement category
A manufacturer statement of the transient over-voltage the instrument is built to survive at a point in an installation — CAT II at socket outlets, CAT III in fixed installation. It is a safety rating, not a quality grade, and a meter that does not state one cannot be placed.
Of five meters we compare, one listing states a category.
The fuse
The current input is protected by a fuse, and that fuse is a safety component. Ceramic sand-filled bodies are specified where a high-energy fault has to be interrupted; glass fuses of the same current rating are not. One listing of five names the type.
True-RMS
If the meter will ever be pointed at a dimmer, an LED driver or a variable-speed drive, it needs true-RMS. An averaging meter assumes a clean sine wave and reads those systematically low.
What not to compare
The count (2000, 6000, 20000). It is display resolution, and it is rarely the limiting factor on a hand-held meter.
What gets asked here
Should I buy the one with the most functions?
No. Capacitance, frequency and temperature are useful occasionally; a category rating and a proper fuse matter every time the meter is used near mains.
What is the most common way a meter is destroyed?
Measuring voltage with a lead still in the current socket — a near short circuit across the supply. One meter we compare lights the correct sockets for the selected function, which is the only design that addresses it.
Last reviewed 31 August 2026