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CAT III 600V multimeter: category and voltage on a UK board

Updated: October 2026

You are about to put probes on a socket or near a consumer unit, and the meter in your hand says CAT III, or it says nothing. A CAT III 600V multimeter mark only means something when a voltage sits beside the category, and that pair matches the place you are in. Peter F. updated this page on 17 October 2026 from the seller's lines and public UK guidance. The [Voltcraft multimeter comparison](/hub/measuring-equipment/voltcraft-multimeter) ranks the twelve files, and none of them is a Voltcraft. A qualifying purchase can earn a commission at no extra cost to you.

You are about to put probes on a socket or near a consumer unit, and the meter in your hand says CAT III, or it says nothing.

Our top picks

VENLAB VENLAB VM-600M

Best overall

VENLAB VENLAB VM-600M
8.7/10about £26.99
View offer
Crenova Crenova MS8233D

Preis-Tipp

Crenova Crenova MS8233D
8.9/10about £22.99
View offer
VENLAB VENLAB VM-600A

Rank 3

VENLAB VENLAB VM-600A
9.4/10about £29.99
View offer
On this page
  1. 1.Where you are measuring
  2. 2.Category plus voltage
  3. 3.What this set prints
  4. 4.What a CAT line does not do

Where you are measuring

Martindale puts CAT II on plug-in loads, CAT III on the building distribution, including socket wiring and the breakers in a consumer unit, and CAT IV on the supply side. Megger puts CAT IV up to the first isolator that opens line and neutral. UK mains are 230 V. The voltage you read is not the transient the category is there to survive. A plugged-in appliance lead is CAT II territory. Socket wiring or a breaker is CAT III on that description. The supply side of the main switch is CAT IV, and this Amazon set is the wrong shelf for that work.

Category plus voltage

A measurement category is two parts: the category and the voltage to earth. CAT III on its own does not say CAT III 600 V. The Crenova 890Z spec line says CAT III and gives no voltage. You cannot fill in 600 V from other rows. CAT II 1000 V does not promote a meter into the distribution category. The UNI-T UT892 prints both pairs, so you read the one that matches the place. This set has no CAT III 1000 V meter. The Kethvoz prints CAT III 300 V, which is above a steady 230 V reading and still a lower transient claim than CAT III 600 V.
VENLAB VENLAB VM-600M

Testsieger

VENLAB VENLAB VM-600M
8.7/10about £26.99
View offer

What this set prints

Three rows print CAT III 600 V: the VM-600A at £29.99, the VM-600M at £26.99, and the MS8233D at £22.99. The Kethvoz prints CAT III 300 V. The 890Z prints CAT III with no voltage. The coczow puts CAT words on the leads, not on the meter. RICOKEY, Beizkna, BSIDE, and FNIRSI print no CAT rating. Rapid's VC191 and VC232 print the pair and are not ASINs here. The best meters page ranks the VM-600A only because the pair is printed. The buying guide is the brand check.

What a CAT line does not do

A CAT line is the seller's text, not an independent certificate. GS38 lists exceeding the category as one way test gear fails, and probes should carry a category of their own. Split insulation on the VM-600A leads, reported in a UK review, means you stop. The line does not prove a circuit dead. Battery, fuse, and the stop point are on the how to use page. In England, a new circuit, a new consumer unit, and work in a bath or shower room are notifiable under Part P.

Common questions

What is the difference between CAT II, CAT III and CAT IV?
Martindale puts CAT II on plug-in loads, CAT III on the building distribution including socket wiring and breakers, and CAT IV on the supply side. Megger puts CAT IV up to the first isolator that opens line and neutral. The steady 230 V you might read is not what separates them. The transient and the fault energy at that place are. A category without a voltage still does not name the place.
Why does the voltage have to sit next to the category?
Because the mark is a pair. Megger treats the category and the voltage to earth as the two parts. CAT III on its own, which is all the 890Z spec line gives you, does not mean CAT III 600 V. CAT II 1000 V does not mean the meter is rated for a consumer unit. Read the pair that matches the place you are in.
Is CAT III on its own enough?
No. The Crenova 890Z prints CAT III and no voltage. You cannot assume 600 V from other rows in this folder. A category without a voltage does not define where the meter belongs. Leave that listing out of a socket or consumer-unit shortlist until a voltage is printed beside the category.
Does CAT III 1000 V beat CAT III 600 V here?
This set does not contain a CAT III 1000 V meter. A higher voltage in another category, such as the UT892's CAT II 1000 V line, does not outrank CAT III 600 V at a consumer unit. At that board you read the CAT III line and its voltage. The Kethvoz CAT III 300 V line is the lower claim of the two.
Are the coczow leads the same as a CAT-rated meter?
No. The coczow bullet puts CAT III and CAT IV on the test leads. That is not a rating of the meter, and it is not a CAT IV instrument. GS38 expects probes themselves to carry a category mark. A lead sentence does not promote the meter into the supply side or the consumer unit.
Does a CAT line mean I can prove the circuit dead?
No. GS38 says you use a test lamp or a two-pole detector, and you prove it before and after. A CAT mark, even CAT III 600 V printed in full, does not change that. Exceeding the category is one way the guidance says test gear fails. If you cannot prove dead, stop. Rapid's VC191 and VC232 print CAT III 600 V and are not in this Amazon folder.

Related pages

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Voltcraft multimeter UK: brand, price and listings

How to use a multimeter: DC volts, continuity, stop

True RMS multimeter: dimmers, drivers and sine waves

Sources

Public UK sources from the research digest for this comparison: Rapid Electronics for the Voltcraft brand and the VC191, VC232 and VC-86 pages, the separate amazon.co.uk VC-86 listing, HSE GS38, the Electricity at Work Regulations 1989 and Fluke. Listing prices, star lines and review themes for the 12 models are the stored amazon.co.uk figures, not a fresh page view. Updated 17 October 2026.

  1. Rapid Electronics, Voltcraft brand (retrieved 17 October 2026)
  2. Rapid Electronics, Voltcraft VC191 (retrieved 17 October 2026)
  3. Rapid Electronics, Voltcraft VC232 (retrieved 17 October 2026)
  4. Rapid Electronics, Voltcraft VC-86 (retrieved 17 October 2026)
  5. amazon.co.uk, Voltcraft VC-86 listing (retrieved 17 October 2026)
  6. HSE GS38, electrical test equipment for electricians (retrieved 17 October 2026)
  7. Electricity at Work Regulations 1989, regulation 16 (retrieved 17 October 2026)
  8. Fluke, true measurements of non-linear loads (retrieved 17 October 2026)