Digital multimeters
A stated safety category, or true-RMS?
Across five multimeters, one listing states a measurement category and one offers true-RMS. They are not the same meter. This page is about which gap you can live with.
| Compared on | CAT III digital multimeter | True-RMS multimeter, 6000 counts |
|---|---|---|
| Measurement category | CAT III stated (voltage not given) | Not published |
| True RMS | Not published | Stated |
| Counts | 3½ digits | 6000 |
| Voltage range | 600 V AC/DC | Up to 600 V |
| Current range | 10 A AC/DC | AC/DC current, range not given |
| Extra functions | Resistance to 20 MΩ, continuity | Temperature, capacitance, frequency, diode, continuity |
| Probe tip caps | Not published | Supplied |
| Auto power-off | After 15 minutes | After 15 minutes |
A tick marks the better answer on that line only. Counting ticks does not decide the page — the two verdicts below do, because these products answer different questions.
Buy the coczow if knowing where the instrument may be used matters more than what it can measure. Stating a category at all puts it ahead of four of the five meters in the hub.
Buy the Brennenstuhl if the meter will be pointed at anything modern. True-RMS is the difference between a correct reading and a systematically low one on dimmers, drives and LED supplies — and read the manual for the category it does not print.
Partly. A category and a voltage are one specification, so CAT III alone is incomplete — and it is still more than the other four meters publish. The full rating is on the instrument and in the manual.
It assumes a clean sine wave and scales its reading accordingly. On a chopped waveform — a dimmer, an inverter, a variable-speed drive — it reads low, sometimes substantially.
CAT III stated · 600 V AC/DC · 10 A · 20 MΩ · auto power-off
The only multimeter in this hub whose listing states a measurement category. It also gives its ranges plainly: 600 V AC and DC, 10 A, 20 MΩ.
Best for: Household and installation fault-finding where knowing the category matters more than the feature list.
≈ $25 / £20 / 21 €
True RMS · 6000 counts · 600 V · temperature, capacitance and frequency
A true-RMS meter with 6000-count resolution and the widest function list here — voltage, current, resistance, temperature, diode, continuity, capacitance and frequency — with probe caps included.
Best for: Household and light installation work where waveforms are not clean and the reading has to be right.
≈ £35 / 32 €
