How to choose an insulation tester
By Grant, Inspection Tool Specialists. Reviewed November 2026.
Three things decide which insulation or earth tester you need: the test voltage your standard requires, whether you measure insulation resistance or earth resistance, and whether you need a clamp that avoids disconnecting the circuit. Answer those first.
Which test?
| Need | Instrument | Typical in our range |
|---|---|---|
| Insulation resistance, low voltage | Insulation tester, 1000 V | DT-5505 1000 V insulation tester |
| Insulation resistance, higher voltage | High-voltage insulation tester | DT-6605 5 kV insulation tester; GM3123 high-voltage tester |
| Insulation and dielectric withstand testing | Hipot tester | HMZGF DC hipot tester, 30 kV |
| Earth resistance, by stakes | Earth resistance tester | DT-5300B earth resistance tester; PCE-ERT 10 |
| Earth resistance without disconnecting, clamp-on | Clamp-on earth and leakage tester | DT-9399 clamp-on tester |
| Insulation with a continuity function | Insulation tester | PCE-IT55 insulation tester |
Safety first
Insulation and hipot tests apply high voltage. Isolate and discharge the circuit before connecting, keep people clear during the test, and follow your electrical safety procedure. Test only by trained, competent people.
Price guide
As a guide to our current range, including VAT: 1000 V insulation testers from about R7,100; high-voltage insulation testers from about R5,200 to R10,300; earth resistance testers from about R5,300 to R15,600; clamp-on testers from about R13,800; DC hipot testers from about R70,700. Prices change, so check the product pages and confirm the leads and calibration each quote includes.
Questions we will ask you
Tell us the test voltage your standard requires, whether you measure insulation or earth resistance, the circuit or equipment, whether you can disconnect it, the earth electrode layout, and the records you must keep. With that we can recommend a tester and provide pricing.