COMPARISON · MULTIMETERS
Fluke 115 vs Extech EX330: Which Multimeter Should You Choose?
Choose the Extech EX330 if you need microamps, temperature or non-contact voltage on a budget; choose the Fluke 115 if your AC readings come off electronic loads and you want a meter built and warranted for daily field use. Oddly, the cheaper meter lists more functions: when we checked Amazon the 115 cost about two and a half times as much, yet it has no microamp range, no thermocouple input and no NCV. The 115's premium buys True RMS, a 6,000-count display, wider capacitance range and Fluke's 3-year warranty.
By the OhmSavvy Research Team ·
Disclosure: OhmSavvy earns a commission from qualifying Amazon purchases made through these links, at no extra cost to you. How we're funded.
Fluke 115
4.8★★★★★The same Fluke reliability as the 117, in the same body, without the electrician-specific extras (NCV, AutoVolt, LoZ).
Extech EX330
4.2★★★★☆A genuinely pocket-sized meter with a non-contact voltage detector built in.
Specs side by side
| Fluke 115 | Extech EX330 | |
|---|---|---|
| Rating | 4.8★★★★★ | 4.2★★★★☆ |
| Accuracy | True RMS | Auto-ranging (True RMS not stated) |
| Safety rating | CAT III 600V | CAT III 600V |
| Auto-ranging | Yes | Yes |
| Best for | Field technicians, general electrical and electronics work | Quick checks, pocket carry |
| AC measurement | True RMS | True RMS not stated by Extech |
| Display | 6,000 counts + 33-segment bar graph, backlit | 4,000 counts |
| Current | 6 A and 10 A AC/DC; 1 mA best resolution | 0.1 µA to 10 A AC/DC |
| Capacitance | 1 nF to 9,999 µF | 0.001 nF to 200 µF |
| Frequency | To 50 kHz | 0.001 Hz to 10 MHz, plus duty cycle |
| Temperature | No | Type K, -4°F to 1382°F; probe included |
| Non-contact voltage | No | Yes, 100 to 600V AC |
| Published accuracy | Yes, e.g. DC V ±(0.5% + 2) | Not on Extech's product page |
| Safety rating | CAT III 600V | CAT III 600V / CAT II 1000V |
| Size / weight | 167 × 84 × 46 mm, 550 g | 147 × 76 × 42 mm, 260 g |
| Battery | One 9V, about 400 h | 2 × AAA |
| Warranty | 3 years | 2 years (Extech); Amazon listing says 1 year |
Specs checked against manufacturer documentation and official Amazon listings. Fluke 115 is hands-on tested by OhmSavvy; the Extech EX330 assessment is desk research. How we research.
Key differences
- →The EX330 measures current down to 0.1 µA; the Fluke 115's smallest current step is 1 mA, so it can't read microamp signals at all.
- →The Fluke 115 is True RMS; Extech doesn't claim True RMS for the EX330, so its AC readings on distorted waveforms are less certain.
- →The EX330 adds a Type K temperature input (probe included), duty cycle and a 100 to 600V AC NCV detector; the 115 has none of the three.
- →The 115 measures capacitance up to 9,999 µF against the EX330's 200 µF.
- →The EX330 weighs 260 g against the 115's 550 g; the 115 has a backlit 6,000-count display and bar graph.
- →Fluke gives the 115 a 3-year warranty; Extech lists 2 years for the EX330, though its Amazon listing says 1 year.
The microamp gap: why the cheaper EX330 wins on flame sensors
A gas furnace proves its flame by passing a tiny DC current through the flame to the sensor rod. Furnace makers typically specify that current in single-digit microamps, so the check needs a meter that resolves fractions of a microamp. Extech lists DC current from 0.1 µA. The Fluke 115's current ranges start at 6 A with 1 mA resolution, which is 10,000 times coarser than the reading you're trying to see; it would show zero.
This isn't a niche gap for anyone doing residential HVAC. If flame sensors are part of your work, the 115 is the wrong Fluke: its sibling the 116 swaps the amp ranges for a 600.0 µA range, as our best multimeters for measuring microamps guide explains. The same limit affects electronics hobbyists who want a microcontroller's sleep current, which is also a microamp job; see how to measure microamps with a multimeter.
Worked scenario: one furnace service call, two meters
Walk through a typical no-heat call on a gas furnace with a variable-speed blower and see where each meter can go. The table uses only what each maker publishes; it isn't a record of readings we took.
| Step on the call | Fluke 115 | Extech EX330 |
|---|---|---|
| Confirm 120V at the furnace disconnect | Yes; CAT III 600V | Yes; CAT III 600V |
| Check the 24V AC thermostat call at the board | Yes | Yes |
| Flame sensor current (a few µA) | No: 1 mA best resolution | Yes: resolves 0.1 µA |
| Supply and return air temperature | No temperature input | Yes, with the included Type K probe |
| Blower motor run capacitor (for example 5 to 10 µF) | Yes | Yes |
| Large filter capacitor on a control board (say 2,200 µF) | Yes: to 9,999 µF | No: over its 200 µF limit |
| Blower current on a variable-speed motor | True RMS: reads distorted waveforms properly | Reads it, but True RMS isn't stated |
| Quick live-wire check before opening a box | Not built in | Built-in NCV, 100 to 600V AC |
On this call the EX330 completes more steps, and that's the honest headline. The 115 only pulls ahead on the large capacitor and on the electronically driven blower, where True RMS matters because the motor draws current in non-sinusoidal pulses. We explain the True RMS arithmetic with a worked example in Fluke 115 vs Klein MM400, so we won't repeat it here. For the capacitor test itself, see how to test a fan motor capacitor.
Pocket meter or truck meter: size, display and warranty
The EX330 is a mini meter: 147 × 76 × 42 mm against the 115's 167 × 84 × 46 mm, and it comes in a rubber holster with a tilt stand. If you carry a meter all day as a backup to a clamp meter, that matters. The 115 answers with a display that resolves 5.999V on its lowest volts range, where a 4,000-count meter has to step up a range, plus a 33-segment bar graph that tracks a drifting reading and a backlight for crawlspaces. Fluke also publishes accuracy for every function, which Extech's product page does not.
On durability we can speak to only one side. We bought a Fluke 115 and used it on our own bench, which is why it carries our Hands-on Tested badge; we haven't published measurements from it. Our view of the EX330 comes from Extech's documentation, not from handling one. The warranty terms back Fluke's position: three years, against two years on Extech's page and one year on its Amazon listing, a conflict worth checking with the seller.
Both stop at CAT III 600V
Who should pay the Fluke premium?
The cheaper meter is the right call more often than you'd think
If you want both True RMS and the EX330's extras, the UNI-T UT139C lists True RMS, NCV and temperature at a budget price; we set it against the EX330 in Extech EX330 vs UNI-T UT139C. For HVAC-specific picks, see the best multimeter for HVAC technicians.
Choose the Fluke 115 if…
- ✓You measure current or voltage on variable-speed motors, LED drivers or inverters, where True RMS matters
- ✓You test large electrolytic capacitors, up to 9,999 µF
- ✓The meter will live in a truck and see daily use, and you want a 3-year warranty
Choose the Extech EX330 if…
- ✓You check furnace flame sensors or other microamp signals
- ✓You want temperature from the Type K probe Extech includes
- ✓You want a built-in NCV detector and a 260 g meter that fits a shirt pocket
Neither if…
You need True RMS and microamps in one Fluke. The 115 has no µA range and the EX330 isn't stated as True RMS; Fluke's 116 trades the 115's 6 A and 10 A ranges for a 600.0 µA range and temperature.
The bottom line
The Extech EX330 is the better buy for HVAC service, appliance repair and home use: it reads microamps, temperature and non-contact voltage that the 115 can't, at well under half the price. The Fluke 115 justifies its premium for technicians working on drives, ECM blowers and LED lighting, where True RMS counts, and for anyone who wants a 6,000-count, 3-year-warranty meter for daily field use.
Frequently asked questions
Can the Fluke 115 test a furnace flame sensor?+
No. Its current ranges start at 6 A with 1 mA best resolution, and flame sensor current is typically a few microamps, so the display would read zero. The Extech EX330 lists DC current from 0.1 µA and can make the check. Within Fluke's range, the 116 is the 115's sibling with a microamp range and temperature input, though it drops the 6 A and 10 A ranges.
Is the Extech EX330 True RMS?+
Extech doesn't list True RMS for the EX330, while it does for its True RMS models, so assume it is average-responding. That's fine on plain utility voltage and resistive loads such as heaters. On variable-speed motors, LED drivers and inverters the waveform is distorted, and the Fluke 115's True RMS reading is the one to trust.
Does the Fluke 115 have non-contact voltage detection?+
No. NCV is one of the features Fluke reserves for the 117, along with LoZ and AutoVolt. The Extech EX330 has an NCV detector rated for 100 to 600V AC with a red LED and beeper. If you want NCV on a Fluke, compare the 115 with the 117 before buying.
Which meter is better for checking capacitors?+
Both handle typical motor run capacitors, which sit in the tens of microfarads. The difference is at the top end: the Fluke 115 reads up to 9,999 µF, while the EX330 stops at 200 µF, so large electrolytic filter capacitors in power supplies and control boards are beyond the Extech's range.
What warranty do the Fluke 115 and Extech EX330 have?+
Fluke gives the 115 a 3-year warranty. Extech's product page lists 2 years for the EX330, but the Amazon listing we checked says 1 year parts and labor. Since the sources disagree, confirm the term with the seller, and keep your receipt either way. Extech's page doesn't publish accuracy figures for the EX330 either.
Is the Fluke 115 worth it for a homeowner over the Extech EX330?+
Usually not. A homeowner checking outlets, batteries, appliance elements and thermostat wiring gets more functions from the EX330, including temperature and NCV, and both are CAT III 600V. The 115 makes sense at home only if you work on inverter appliances or solar equipment where True RMS matters, or want a meter built and warranted for years of hard use.
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