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An insulation tester (megohmmeter) checks insulation on motors and cables. It uses high test voltages and is for trained users.

Electrical work can be dangerous. Always follow the instructions, use the right safety rating for the job and call a licensed electrician if you are unsure.

This guide is built from Amazon product listings, not our own testing, so confirm specs, safety ratings and current price on each product page.

Prices are approximate US dollar conversions of what Amazon showed on October 31, 2026.

Last updated: October 31, 2026.

Quick Picks

Product Type Best for
T6125 Digital Insulation Resistance Tester Insulation tester 2500V, up to 200 GΩ
UNI-T UT501A Megohmmeter Insulation tester 1000V
2500V Megohmmeter and True RMS Multimeter Insulation tester and multimeter 50 GΩ
Insulation Resistance Tester (50V-1000V) Insulation tester Up to 100 GΩ
ennoLogic eM870M Insulation Tester Insulation tester Five test voltages
Klein Tools ET600 Insulation tester and multimeter Megohmmeter multimeter

Our Picks

1. T6125 Digital Insulation Resistance Tester

A T6125 digital insulation resistance tester, 2500V, 0.01 MΩ to 200 GΩ, per the listing. It was shown at about $80 on Amazon.com on October 31, 2026.

Good for: 2500V, up to 200 GΩ. Watch out: professional use.

Check on Amazon

2. UNI-T UT501A Megohmmeter

A UNI-T UT501A megohmmeter insulation tester, 1000V, per the listing. It was shown at about $82 on Amazon.com on October 31, 2026.

Good for: 1000V. Watch out: professional use.

Check on Amazon

3. 2500V Megohmmeter and True RMS Multimeter

A 2500V megohmmeter and True RMS multimeter for industrial testing, 50 GΩ, per the listing. It was shown at about $85 on Amazon.com on October 31, 2026.

Good for: 50 GΩ. Watch out: professional use.

Check on Amazon

4. Insulation Resistance Tester (50V-1000V)

A megohmmeter insulation resistance tester, 50V to 1000V, up to 100 GΩ, per the listing. It was shown at about $100 on Amazon.com on October 31, 2026.

Good for: Up to 100 GΩ. Watch out: professional use.

Check on Amazon

5. ennoLogic eM870M Insulation Tester

An ennoLogic eM870M insulation tester with 50/100/250/500/1000V megohmmeter, per the listing. It was shown at about $130 on Amazon.com on October 31, 2026.

Good for: Five test voltages. Watch out: higher price.

Check on Amazon

6. Klein Tools ET600

A Klein Tools ET600 megohmmeter insulation tester multimeter, per the listing. It was shown at about $192 on Amazon.com on October 31, 2026.

Good for: Megohmmeter multimeter. Watch out: high price.

Check on Amazon

How to Choose

Test voltage

Match the equipment rating.

Range

Check upper limit.

Safety

De-energize and discharge first.

Frequently Asked Questions

Who needs one?

Electricians and maintenance staff.

Cheapest?

T6125 or UT501A.

Brand?

Klein.

Bottom Line

For value, the UNI-T UT501A or T6125. For a combined tool, the Klein ET600.

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