COMPARISON · MULTIMETERS
Fluke 87V vs Extech EX505A: Which Is Better for Industrial Testing?
Both meters carry the same CAT IV 600V / CAT III 1000V rating, so the choice comes down to the work itself. Plant technicians who troubleshoot variable-frequency drives, calibrate 4–20 mA loops or chase intermittent faults should buy the Fluke 87V: it has a low-pass filter, 250 µs peak capture and DC accuracy ten times tighter. Buy the Extech EX505A for washdown areas, outdoor yards and rough sites, where its IP67 housing matters more than precision. The 87V cost nearly four times as much on Amazon when we checked.
By the OhmSavvy Research Team ·
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Fluke 87V
4.8★★★★★The step-up pick for anyone who needs CAT IV protection and high-resolution readings daily.
Extech EX505A
4.5★★★★★An IP67, CAT IV 600V True RMS meter that survives a 2 m drop, with µA to 10 A and temperature, but no LoZ or filter.
Specs side by side
| Fluke 87V | Extech EX505A | |
|---|---|---|
| Rating | 4.8★★★★★ | 4.5★★★★★ |
| Accuracy | True RMS | True RMS, 6,000-count, ±(0.5% + 5) DC V |
| Safety rating | CAT III 1000V / CAT IV 600V | CAT IV 600V / CAT III 1000V |
| Auto-ranging | Yes | Yes (manual RANGE) |
| Best for | Industrial technicians, daily professional use | Wet, dusty or rough industrial sites |
| Safety category | CAT III 1000V / CAT IV 600V | CAT IV 600V / CAT III 1000V (manual) |
| Display | 6,000 counts; 19,999 high-res mode | 6,000 counts |
| DC volts accuracy | ±(0.05% + 1) | ±(0.5% + 5) |
| AC volts band | To 20 kHz; low-pass filter 3 dB at 1 kHz | 50 Hz–1 kHz sine, 50/60 Hz other waveforms; no filter |
| Peak capture | 250 µs | Not listed |
| 60 mA DC range accuracy | ±(0.2% + 4) | ±(1.0% to 1.5% + 3), by range grouping |
| Finest current step | 0.01 µA DC | 0.1 µA |
| Capacitance | To 9,999 µF | To 99.99 mF |
| Temperature | -200 to 1090 °C, probe extra | -20 to 760°C; supplied probe rated 250°C |
| Ingress / drop | IP30; drop 3 m or 1 m (Fluke sources differ) | IP67; 2 m drop |
| LoZ / NCV | Neither listed | Neither listed (LoZ on EX520A/EX530A only) |
| Weight / battery | 355 g (624 g in holster); 9 V, about 400 h | 365 g; one 9 V |
| Warranty | Lifetime | 3 years |
Specs checked against manufacturer documentation and official Amazon listings. Fluke 87V is hands-on tested by OhmSavvy; the Extech EX505A assessment is desk research. How we research.
Key differences
- →The 87V has a low-pass filter for drive outputs; Extech's datasheet gives the filter only to the EX520A and EX530A, not the EX505A.
- →Fluke specifies 87V DC volts at ±(0.05% + 1); the EX505A is ±(0.5% + 5), ten times the percentage term.
- →The EX505A is IP67 and drop-tested to 2 m; Fluke's comparison table lists the 87V at IP30.
- →The 87V has 250 µs peak capture and a 19,999-count high-resolution mode; Extech lists neither on the EX505A.
- →Extech specifies the EX505A's AC volts for non-sine waveforms at 50/60 Hz only; Fluke gives the 87V a 20 kHz bandwidth.
- →The EX505A reads capacitance to 99.99 mF, ten times the 87V's 9,999 µF.
A 480 V drive running a conveyor at 40 Hz
This is the job that splits the pair. A drive feeding a 480 V motor at reduced speed produces a PWM waveform, not a sine wave, at a fundamental below 60 Hz. Fluke built the 87V for it: a low-pass filter rolls off at 3 dB at 1 kHz so the meter reports something close to the fundamental the motor sees. Extech's manual for the EX505A specifies AC volts from 50 Hz to 1 kHz for sine waves and at 50/60 Hz for all other waveforms, and the datasheet marks the low-pass filter as absent on this model.
Put those together and a 40 Hz PWM output falls outside the EX505A's specification twice over: it is below 50 Hz, and it isn't a sine. The meter will display a number, but Extech makes no accuracy claim for it. The 87V, with its filter, gives a reading you can compare phase to phase and against the drive's own display. We cover drive measurement on the 87V in more depth in Fluke 87V vs Fluke 179, which is the comparison to read if drives are your main job.
If you want Extech with a filter
A 4–20 mA loop and a 24 V DC supply: where 0.05% shows
Instrument technicians feel the accuracy gap more than electricians do. Worked on each maker's spec for a transmitter reading 12.00 mA: the 87V's 60 mA range at ±(0.2% + 4 digits) allows ±(0.024 + 0.04) = ±0.064 mA. Extech's manual table groups its DC current ranges at ±(1.0% + 3) and ±(1.5% + 3), and the layout doesn't make clear which applies to 60.00 mA, so we take the looser figure: ±(0.18 + 0.03) = ±0.21 mA. Across a 16 mA span that is 0.4% of span on the Fluke against 1.3% on the Extech.
The same pattern holds on a 24.00 V control supply read on the 60 V range: the 87V allows ±(0.012 + 0.01) = ±0.022 V and the EX505A ±(0.12 + 0.05) = ±0.17 V. Both are fine for "is the supply up?". Only the Fluke is tight enough to judge a supply against a ±1% tolerance with margin.
For loop work specifically, our 4–20 mA loop testing picks include process meters that source as well as measure.
Washdown, rain and drops: what IP67 buys
The EX505A's strongest card is its housing. Extech says it is double-molded, rated IP67 (tested by Bureau Veritas, per the manual) and drop-tested to 2 m. IP67 means dust-tight and protected against temporary immersion. Fluke's comparison table lists the standard 87V at IP30, which means no rated water protection, and Fluke's own pages differ on its drop rating: 3 m in the comparison table, 1 m in the spec tab's shock line.
On a food plant's washdown floor, a wastewater site or an outdoor substation yard, that difference decides more than any accuracy figure. The EX505A also comes with a carrying case, magnetic hanging strap and Type K bead probe, though Extech rates that probe only to 250°C even though the meter reads to 760°C. If you want the 87V's filter and accuracy in a sealed body, Fluke's 87V MAX is IP67; we compare it in Fluke 87V vs 87V MAX.
Plant jobs side by side
| Job | Fluke 87V | Extech EX505A |
|---|---|---|
| 480 V drive output at 40 Hz | Low-pass filter, 3 dB at 1 kHz | Outside spec (non-sine, below 50 Hz) |
| Loop at 12.00 mA | ±0.064 mA | Up to ±0.21 mA |
| 24.00 V control supply | ±0.022 V | ±0.17 V |
| Motor inrush or a dropout | 250 µs peak capture | Not listed |
| Washdown area or rain | IP30 | IP67 |
| 20,000 µF bus capacitor (de-energized) | Over its 9,999 µF limit | Within 99.99 mF, ±10% |
| Bearing at 120°C | With a suitable probe (extra) | Supplied probe, rated to 250°C |
We bought and tested the 87V on our own bench, and the Fluke 87V review explains what that covered. The EX505A assessment comes from Extech's manual, datasheet and product page; we haven't had one on the bench. For a wider field, the best multimeter for electricians roundup ranks CAT IV meters across price tiers.
CAT IV needs CAT IV leads and real PPE
Choose the Fluke 87V if…
- ✓You measure variable-frequency drive outputs and need a low-pass filter
- ✓You calibrate or verify 4–20 mA loops and 24 V DC supplies against tight tolerances
- ✓You need peak capture for inrush and transients, or temperature to 1090 °C with a suitable probe
Choose the Extech EX505A if…
- ✓The meter will get wet, dusty or dropped: it is IP67 with a 2 m drop rating
- ✓Your work is 50/60 Hz mains, motors and controls rather than drive outputs
- ✓You need capacitance beyond 10,000 µF, up to 99.99 mF
Neither if…
You need both drive-output accuracy and a waterproof meter. The Fluke 87V MAX keeps the 87V's filter and ±(0.05% + 1) DC accuracy in an IP67 body with a 4 m drop rating.
The bottom line
For industrial testing the Fluke 87V is the better meter: a low-pass filter for drives, 250 µs peak capture and DC accuracy ten times tighter make it the right tool for maintenance and instrumentation work. The Extech EX505A is the better buy where the meter takes abuse, with the same CAT IV 600V rating, IP67 sealing and a 2 m drop rating at roughly a quarter of the price, as long as you don't need to read drive outputs.
Frequently asked questions
Does the Extech EX505A have a low-pass filter?+
No. Extech's EX5xxA datasheet lists the low-pass filter and LoZ for the EX520A and EX530A and marks both as absent on the EX505A. The manual also specifies AC volts for non-sine waveforms at 50/60 Hz only, so drive outputs fall outside its accuracy specification. The Fluke 87V's filter is rated 3 dB at 1 kHz.
Is the Fluke 87V waterproof?+
Fluke's comparison table lists the standard 87V at IP30, which means protection against solid objects but no rated water protection. The Extech EX505A is IP67, dust-tight and protected against temporary immersion. If you want Fluke's measuring performance in a sealed meter, the Fluke 87V MAX is rated IP67 with a 4 m drop rating.
Is the EX505A accurate enough for 4–20 mA work?+
For checking that a loop is alive and roughly where it should be, yes. On a 12.00 mA signal, the manual's looser DC current figure allows about ±0.21 mA, or 1.3% of a 16 mA span. The Fluke 87V allows about ±0.064 mA on the same reading. For calibration against a tight tolerance, the Fluke is the better choice.
What is the difference between the Extech EX505 and EX505A?+
Extech lists the EX505A as the current model that replaces the discontinued EX505. The EX505A is a 6,000-count True RMS meter rated CAT IV 600V / CAT III 1000V with IP67 sealing and a 2 m drop rating. We compared only the EX505A here, using its 2024 datasheet and current manual; we didn't verify the older EX505's specifications.
Why does the Extech datasheet say 0.09% accuracy?+
The EX5xxA datasheet covers three models, and one feature bullet says 0.09% next to the EX505A heading. The same datasheet's specification table gives the EX505A ±0.5% basic accuracy and the EX520A ±0.09%, and the EX505A manual specifies DC volts at ±(0.5% + 5). We use the manual's figure and treat the bullet as an error.
Can the EX505A measure high temperatures?+
The meter reads Type K thermocouples from -20 to 760°C, but Extech rates the supplied bead probe only to 250°C and warns that exceeding it can damage the probe and the meter. For hotter surfaces you need a separately rated probe. The Fluke 87V reads -200 to 1090 °C, with the probe sold separately and its own rating applying.
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