Fluke 115 vs Fluke 101: Which Multimeter Should You Buy for Industrial Maintenance?

If you're buying a multimeter for an industrial maintenance team, skip the Fluke 101. The extra $100 for the Fluke 115 True RMS saves you at least three times that in callbacks and diagnostic errors within the first year.

I manage purchasing for a 60-person engineering firm—about $80,000 annually across 12 vendors for office supplies and electrical test equipment. When I took over purchasing in 2021, the senior tech asked me to find a "good basic meter" for our team of 5 maintenance guys. I almost went with the Fluke 101 at $55. Glad I didn't.

Here's what I learned from 6 months of ordering, returns, and one very angry lead technician.

The Short Answer: Buy the Fluke 115 True RMS

The Fluke 115 True RMS Digital Multimeter lists around $169–$179. The Fluke 101 Basic Digital Multimeter is about $55. On paper, that's a $120 gap. In practice, the 115 paid for itself in under four months.

Why? Because industrial maintenance isn't home wiring. You're testing home solar inverters, diagnosing magnetic contactor coils, figuring out what is a relay electrical faults—those require measuring non-linear loads and variable frequency drives. The 115 handles that. The 101 doesn't.

Here's a quick cost comparison I put together from our 2024 purchasing records:

• Fluke 101 Basic Digital Multimeter — $55 unit cost. No True RMS. Limited AC bandwidth (400 Hz). No temperature. Great for basic continuity checks on dead circuits. Not great for live troubleshooting.
• Fluke 115 True RMS Multimeter — $173 unit cost. True RMS. 20 kHz AC bandwidth. Capacitance. Diode test. Min/Max/Average recording. This is where the real work gets done.

I know what you're thinking: "But the 101 is so much cheaper!" Take it from someone who processed 18 returns last year—cheaper upfront isn't cheaper when it doesn't solve the problem.

The Fluke 101 is Actually Decent—For Homeowners

Let me be fair here. The Fluke 101 is a solid meter for its price. It's CAT II rated, safe for residential branch circuits, and more accurate than any $15 special from the hardware store. If you're diagnosing a light switch or checking battery voltage on your car, it's perfectly fine.

But here's what we learned the hard way: an industrial maintenance team isn't measuring household circuits. They're testing VFD output, checking solar inverter harmonics, and troubleshooting relay coils that switch inductive loads. Those are non-sinusoidal waveforms. The 101 displays an average reading for those. The 115 shows the actual RMS value.

Actual: our lead tech spent 3 hours chasing a "bad" magnetic contactor because the 101 was reading 220V but the actual RMS was 198V—enough to chatter the coil. The contactor wasn't bad; the meter was. New contactor: $45. Lost labor: $240. That's one lesson at a cost of $285, on a meter that was $55.

Let's Talk About the Fluke 115 True RMS in Practice

I ordered five Fluke 115 units in March 2024 after our budget got approved. Here's what I saw in the first three months:

• Accuracy on solar inverter output: Our solar tech was diagnosing a home solar inverter that kept throwing ground fault errors. The 115 showed the precise voltage dip at startup. The 101 (from another tech) showed a flat line. Issue found: failing capacitor in the inverter's MPPT circuit.
• Relay coil diagnostics: When trying to figure out what is a relay electrical fault in a 480V control panel, the 115's Min/Max mode captured the voltage sag as the relay pulled in. Without that, you're just guessing whether the coil is getting enough voltage.
• VFD output measurement: The 115's 20 kHz bandwidth can handle variable frequency drive outputs up to about 400 Hz accurately below 1000V. Now, the 115 still isn't ideal for VFD work (you want an oscilloscope or a proper VFD meter), but it's way more capable than the 101's 400 Hz limit.

Really, the difference isn't the specs on paper. It's that the 115 gives you information when something goes wrong. The 101 just gives you a number.

Here's another thing nobody tells you about the Fluke 115: the built-in temperature measurement. If your maintenance involves checking electrical connections for heat, electrical panels, or motor bearings, the thermocouple input saves you from buying a separate IR thermometer. It's not as good as a dedicated thermal imager, but for spot-checking temperature on a terminal block, it's perfectly adequate. Saved us maybe $150 on a dedicated probe.

What About the Fluke 87V? (The "If Money Were No Object" Option)

I'm not a technician, so I can't speak to every nuance of measurement accuracy. What I can tell you from a procurement perspective is: the 115 is the sweet spot for general industrial maintenance. The Fluke 87V Max runs about $400. Is it better? Absolutely. Does your maintenance team need it? Probably not unless they're doing precision electronics repair or aerospace work.

We bought one 87V for the lead tech. The other four techs have 115s. Not one complaint about the 115 from them. The 87V lives in the lead tech's bag and rarely comes out.

Cost Breakdown Over Two Years

Here's the math based on our actual spending from 2023 to 2024:

Option A: Fluke 101 ($55 each × 5 units = $275)
- + $285 from that one contactor misdiagnosis
- + ~2 hours per quarter troubleshooting false readings across the team (conservative)
- = about $560/year in hidden costs

Option B: Fluke 115 True RMS ($173 each × 5 units = $865)
- No misdiagnosis costs from inaccurate readings
- Zero callbacks on solar inverter diagnostics

The 115s cost $590 more upfront. They saved that in under one year through fewer mistakes and faster troubleshooting. Honestly, the payback was closer to 9 months when you factor in the frustration factor.

Now, I might be misremembering the exact number of hours saved, but our operations manager noted that after switching to the 115, the maintenance team reduced diagnostic time on complex faults by roughly 25%. It's not a scientific study, but it's our experience.

When the Fluke 101 Actually Makes Sense

My experience is based on ordering for an industrial maintenance team of 5 people doing electrical troubleshooting on motors, controls, and solar equipment. If you're working with a different setup, your experience might differ.

The Fluke 101 is a good choice if:

• You're a homeowner checking outlets and switches—$55 is plenty.
• You're a basic electrician doing only residential wiring—no VFDs, no solar, no industrial controls.
• You need a backup meter for quick continuity tests—toss it in the toolbag and forget.
• Budget is extremely tight and the team isn't working on non-linear loads.

But if you're maintaining anything with variable frequency drives, solar inverters, magnetic contactors, or PLC-controlled relay circuits, the Fluke 115 True RMS is the minimum viable tool. The 101 will let you down when you need it most.

I wish someone had told me this before I put in that first purchase order. Would've saved us a $285 mistake.