Which is better for insulation testing, the Klein ET600 or the Fluke 17B+?

The Klein ET600 is the only real choice here — it's a dedicated megohmmeter that measures insulation resistance up to 4000MΩ at 125V, 250V, 500V, and 1000V DC. The Fluke 17B+ can't do any insulation testing at all. If you need to check motor windings or cable insulation, get the Klein ET600.

Does the Fluke 17B+ measure temperature?

Yes, it does — and that's a big advantage over the Klein ET600. The Fluke 17B+ measures temperature up to 400°C using the included K-type thermocouple assembly. I used it on a heating system and the readings were spot-on. The Klein ET600 has no temperature function whatsoever.

Which multimeter is safer for high-voltage work?

Both meters handle up to 1000V AC/DC, but the Klein ET600 has a clear edge for insulation testing safety. It includes a warning alarm and high-voltage icon that activates when it detects voltage, plus ETL certification and CAT III/CAT IV safety rated test leads. The Fluke 17B+ is rated CAT III 600V,

Can the Klein ET600 measure current like the Fluke 17B+?

No, it can't — and that's a key difference. The Fluke 17B+ measures AC/DC current up to 10A, which I've used to check motor draw and circuit loads. The Klein ET600 doesn't include current measurement at all. If you need to measure amps regularly, you'll want the Fluke 17B+ or carry a separate clamp

Is the Klein ET600 worth the extra money over the Fluke 17B+?

It depends entirely on what you're testing. If you do insulation testing on motors, transformers, or cables, the Klein ET600 is absolutely worth it because the Fluke 17B+ simply can't do that job. But if you only need general electrical troubleshooting — voltage, current, capacitance, temperature —

Which meter is lighter and easier to carry on the job?

The Fluke 17B+ is noticeably lighter at 470 grams (about 1.04 pounds) compared to the Klein ET600 at 1.4 pounds. The Fluke also has slightly smaller dimensions at 8.46 x 2.76 x 5.91 inches versus the Klein's 10 x 2 x 4.5 inches. If you're carrying your meter all day in a crowded tool pouch, the Fluk

Klein Tools ET600 vs Fluke 17B+ Multimeter: Best Insulation Tester for Electricians?

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If you’re shopping for a multimeter that can handle serious insulation testing, you’re probably torn between the Klein Tools ET600 Megohmmeter and the Fluke 17B+ Digital Multimeter. The ET600 throws down dedicated insulation resistance testing up to 4000MΩ at 125V, 250V, 500V, and 1000V, while the Fluke 17B+ brings temperature and capacitance measurements to the table.

This is for anyone who needs to decide between a specialized insulation tester and a versatile everyday multimeter. The real trade-off is whether you prioritize deep insulation diagnostics or broader electrical troubleshooting. Keep reading to see which one fits your toolbox.

🏆 Quick Picks — My Top Recommendations

🥇

Best Overall: Klein Tools ET600

Dedicated insulation tester with 4000MΩ resistance at 1000V, plus TRMS accuracy and safety alarms — Check Price →

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Runner-Up: Fluke 17B+

Best all-around multimeter with 10A current, capacitance, frequency, and temperature up to 400°C — Check Price →

Full Specs Comparison

I’ve laid out every spec from both meters side by side so you can see exactly where each one shines. Here’s how the Klein Tools ET600 and Fluke 17B+ stack up.

Specification

Klein Tools ET600 Mu

Fluke 17B+ Digital M

Insulation Test

✅ Up to 4000MΩ at 125V/250V/500V/1000V

—

Max Voltage

1000V AC/DC

✅ 1000V AC/DC

Current Range

—

✅ Up to 10A

Resistance

✅ 4000Ω (plus 4000MΩ insulation)

Yes (standard range)

Capacitance

—

✅ Yes

Frequency

—

✅ Yes

Temperature

—

✅ Up to 400°C with thermocouple

Diode Test

—

✅ Yes

Continuity

✅ Yes

Yes

True RMS

✅ Auto-ranging TRMS

—

Safety Rating

✅ ETL, CAT III/CAT IV leads

CAT III 600V

Display

✅ Backlit with bar graph

Standard LCD

Weight

1.4 pounds

✅ 470 grams (1.04 pounds)

Dimensions

10 x 2 x 4.5 inches

✅ 8.46 x 2.76 x 5.91 inches