CAT rating multimeter UK
Updated: 22 October 2026
You can see CAT III 600 V or CAT IV 600 V on a PeakTech listing and you need the place in a UK installation those words refer to. A CAT rating multimeter UK question is category plus voltage, then the leads, then the job this meter must not sign. The [PeakTech multimeter comparison](/hub/measuring-equipment/peaktech-multimeter) shows what each model prints. This page is the rule. The Products Compared editorial team used Martindale, Megger, HSE GS38 and the listings scraped on 21 October 2026. We did not impulse-test any meter. A qualifying purchase through our links can earn a commission at no extra cost to you.
You can see CAT III 600 V or CAT IV 600 V on a PeakTech listing and you need the place in a UK installation those words refer to.
You can see CAT III 600 V or CAT IV 600 V on a PeakTech listing and you need the place in a UK installation those words refer to. A CAT rating multimeter UK question is category plus voltage, then the leads, then the job this meter must not sign. The PeakTech multimeter comparison shows what each model prints. This page is the rule. The Products Compared editorial team used Martindale, Megger, HSE GS38 and the listings scraped on 21 October 2026. We did not impulse-test any meter. A qualifying purchase through our links can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Category | Type | Counts | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  PeakTech PeakTech P 3440 | CAT III/IV 1000/600 V | Graphic handheld | 50,000 | 8.0 | about £204.17 | View offer |
| Alternative |  PeakTech PeakTech P 3442 | CAT III/IV 1000/600 V | LCD handheld | Up to 60,000 | 7.6 | about £162.90 | View offer |
| Best value |  PeakTech PeakTech P 4350 | CAT III 600 V | 80 A clamp | 4,000 | 6.7 | about £75.18 | View offer |
On this page
Where CAT III and CAT IV sit
Martindale’s map is the one to keep. CAT II covers socket outlets and plugged-in appliances. CAT III covers distribution, such as the consumer unit and the circuits that leave it. CAT IV covers the supply origin: the tariff meter and the service fuse. Megger puts CAT IV between the supply source and the first isolator that disconnects line and neutral. A rating with no voltage does not tell you the limit, and a higher category means larger clearances, not a better screen. Leads have to be marked for the same place as the work. A kettle flex on a ring final is a different place from a meter tail. The four PeakTech strings below only make sense against that map.
What these four listings actually print
The P 3440 at £204.17 and the P 3442 at £162.90 print CAT III 1000 V and CAT IV 600 V, with EN 61010-1. Both also print TÜV / GS, a German safety mark in the amazon.co.uk text. It is not UKCA, and it does not add a category. The P 4350 at £75.18 and the P 1650 at £77.70 print CAT III 600 V only. The P 4350 cites EN 61010-1 and does not print GS. A P 1650 bullet says the clamp is suitable for electricians, which does not move it to CAT IV. On the P 3440, keep the second figure: the title carries CAT III 1000 V and CAT IV 600 V, and a separate field says maximum operating voltage 600 volts. The buying guide applies this split to a basket. The voltage number alone is the usual misreading.
Why the voltage number alone misleads
Category is a transient test, not another way of writing the voltage. Martindale’s point is that CAT III 600 V and CAT IV 600 V are not the same test. A CAT III meter marked 1000 V is not a free upgrade over CAT IV at 600 V, because the letters describe the energy at that place. Unitest warns the other way: CAT II at 1000 V is not safer than CAT III at 600 V. That is why the clamps’ 600 V line does not make them service-head tools, and why the handhelds’ CAT III 1000 V does not erase the CAT IV 600 V beside it. Use the pair that matches where you connect. The leads can set a lower ceiling than the meter, which is the next limit.
Leads have their own rating
GS38 expects leads to BS EN 61010-031, marked with a category, with finger barriers, and an exposed tip no more than 4 mm, preferably 2 mm. For a multimeter it recommends an HBC fuse usually not above 500 mA. Exceeding the lead category is listed as a cause of arcing. A GS38 footnote notes that fused leads can add up to about 2 ohms, which shows up on a low-ohm check. None of the four component lists states tip length, a lead fuse or a lead category. The INFO lines name test leads, a case and a probe. Lead-only ASINs were removed from this category and are not evidence for these pouches. Assume nothing about a 2 mm GS38 tip. Seating the leads is on the how to use page. After the leads, the limit is competence.
A safe meter is not a competent test
Electricity at Work Regulations 1989, regulation 16, requires competence or supervision where knowledge is needed to prevent danger. A CAT mark does not supply that. BS 7671 regulation 643.1, as SELECT’s Best Practice Guide 7 explains, calls for BS EN 61557 instruments for installation testing. These four meters will not produce an Electrical Installation Certificate because the category looks right. HSG85 does not recommend a multimeter for proving dead, because the function can be wrong. Stop before the supply side if you are holding only CAT III 600 V. The P 3440 and P 3442 print CAT IV 600 V and still do not replace a multifunction tester. Who each listing suits as a meter is on the best PeakTech multimeter page.
Common questions
What is the difference between CAT III 600 V and CAT IV 600 V?
They are different places, even though both say 600 V. Martindale puts CAT III on distribution and CAT IV at the supply origin, including the tariff meter and the service fuse. Megger puts CAT IV between the supply and the first isolator that opens line and neutral. The P 4350 and P 1650 print CAT III 600 V. The P 3440 and P 3442 print CAT IV 600 V as well as CAT III 1000 V. Match the letters to the place. Leads need the same category as the work.
Is CAT III 1000 V better than CAT IV 600 V?
It is a different rating, not a higher one you can swap. The 1000 V figure is the CAT III test. The 600 V figure beside CAT IV is the supply-origin test. On the P 3440 and P 3442 you get both lines, and you use the line that matches the connection. The clamps in this set stop at CAT III 600 V. Picking the larger voltage and ignoring the letters is the misreading this page is here to stop.
Can the P 4350 or P 1650 be used on meter tails?
Their printed rating is CAT III 600 V, and tails at the service head sit in the CAT IV part of Martindale’s map. The P 4350 jaw is also limited to 12 mm. The P 1650 title prints no jaw size. A later sales line and the maker’s 30 mm figure do not change CAT III 600 V. The handhelds print CAT IV 600 V, and that point still needs a competent person, matching leads, and a proper proving method.
Does TÜV / GS raise the category?
TÜV / GS on the P 3440 and P 3442 is a German safety mark in the listing text. It is not UKCA and it is not an extra category. The P 4350 does not print GS. Category remains CAT III 1000 V and CAT IV 600 V on the handhelds, and CAT III 600 V on the clamps. A GS logo does not make the pouch leads into GS38 leads, because tip length and fuse rating are absent. Read the CAT string, then read GS38 for the leads.
Are the leads in the pouch GS38 leads?
The listings do not say. GS38 wants a category mark, finger barriers, a tip no more than 4 mm and preferably 2 mm, and an HBC fuse usually not above 500 mA. The INFO lines list test leads and stop. Separate lead-set ASINs were removed, so they are not proof of what is in these cases. Fused leads can add up to about 2 ohms, which GS38 notes. If the work needs GS38 leads, buy leads that state those facts.
Does a CAT IV meter replace a multifunction tester?
The P 3440 and P 3442 print CAT IV 600 V and remain multimeters. BS 7671 regulation 643.1 expects BS EN 61557 instruments for installation testing, which SELECT’s guide states in plain terms. A colour screen or 50,000 counts does not create loop, RCD or insulation tests. HSG85 still wants a voltage indicator, not a multimeter, to prove dead. Use the CAT IV meter as a meter inside its rating, and leave certificate work to the right instrument and a competent person.
Related pages
Sources
Public sources listed in the research digest. Shelf prices and star lines are the amazon.co.uk figures on these four listings. The price bands are this set, not a market average.
- Martindale Electric: measurement categories explained (retrieved 22 October 2026)
- HSE GS38: electrical test equipment for electricians (retrieved 22 October 2026)
- Electricity at Work Regulations 1989, regulation 16 (retrieved 22 October 2026)
- HSE: electrical FAQs (retrieved 22 October 2026)
- SELECT Best Practice Guide 7 (retrieved 22 October 2026)
- Fluke: what is true-RMS (retrieved 22 October 2026)
- PeakTech P 3440 manufacturer page (retrieved 22 October 2026)
- GOV.UK: Electrical Equipment (Safety) Regulations 2016 (retrieved 22 October 2026)