Klein CL390 vs CL710

Choose the Klein CL390 for HVAC work needing its 200 µA DC lead range and contact temperature measurement. Choose the CL710 for general electrical work needing 600 A AC/DC clamp current, LoZ and higher CAT markings; it gives up the CL390's documented microamp and temperature functions.

These are manufacturer specifications, checked against the CL390 manual and CL710 manual. Our recommendations follow the functions you need, rather than model-number order.

• 200 µA DCCL390's separate test-lead range
• 600 A AC/DCCL710's maximum specified clamp-current range

Quick picks

Compare specifications and all conditions

DC microamps and contact temperature in one clamp meter

Our pick

CL390

The deciding trade-off

Those functions are documented; LoZ is not

LoZ, higher electrical ranges and an illuminated dial

Our pick

CL710

The deciding trade-off

No documented temperature or DC microamp function

Keeping HVAC functions while adding LoZ

Our pick

Compare CL810 before switching

The deciding trade-off

A separate model with microamps, temperature, LoZ, inrush and a worklight

Full comparison table ↔

Swipe to compare. Row labels stay visible.

Your priority	Our pick	The deciding trade-off
DC microamps and contact temperature in one clamp meter	CL390	Those functions are documented; LoZ is not
LoZ, higher electrical ranges and an illuminated dial	CL710	No documented temperature or DC microamp function
Keeping HVAC functions while adding LoZ	Compare CL810 before switching	A separate model with microamps, temperature, LoZ, inrush and a worklight

Your priority	Our pick	The deciding trade-off
DC microamps and contact temperature in one clamp meter	CL390	Those functions are documented; LoZ is not
LoZ, higher electrical ranges and an illuminated dial	CL710	No documented temperature or DC microamp function
Keeping HVAC functions while adding LoZ	Compare CL810 before switching	A separate model with microamps, temperature, LoZ, inrush and a worklight

The first two are our comparison picks. The CL810 is an alternative to investigate if neither feature set fits. For a broader shortlist, see our best clamp meters.

CL390 vs CL710: specifications side by side

Klein's CL390 product page and CL710 product page supply the headline specifications below; the linked manuals supply current resolution and operating limits.

The higher-current meter has the smaller jaw. Check conductor fit separately from electrical range; the CL710's larger current ceiling does not make it physically roomier.

Best for HVAC functions: Klein Tools CL390

The CL390 is our pick when the reason for buying is a missing microamp or temperature function. Klein documents AC/DC clamp current up to 400 A, voltage up to 600 V, a 200 µA DC lead range, K-type temperature, capacitance, continuity and diode testing. You can keep that collection of functions without assuming that a higher model number retains them.

Its temperature headline needs qualification. The meter's specified range reaches 1000°C, but the current manual limits the supplied thermocouple to temperatures below 230°C / 446°F. Higher temperatures require an appropriately rated K-type probe. The meter range alone does not establish what the included probe can tolerate. See the temperature instructions.

The main sacrifice is LoZ: Klein documents no such mode for the CL390. Its safety marking is CAT III 600V. If LoZ is already the feature you miss, buying this model will not fill that gap.

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Best for general electrical work: Klein Tools CL710

Choose the CL710 when higher ranges and LoZ solve your actual problem. Its documented ceilings are 600 A AC/DC and 1000 V AC/DC in the regular voltage function, with CAT IV 600V / CAT III 1000V markings. Klein also lists an illuminated dial and a transflective reverse-contrast display. That is a useful combination if your temperature and microamp needs are already covered elsewhere.

Does the CL710 really include temperature?

The CL710 page contradicts itself. A feature bullet includes a thermocouple, but the specification table shows a dash for temperature range, says “No” for DC microamps, and omits a thermocouple from its included-items list. The manual provides no temperature or microamp measurement function.

Our buying recommendation is to treat both functions as unavailable. Do not buy a thermocouple expecting it to add an undocumented temperature mode. For the combination of these functions with LoZ, investigate the separately specified CL810.

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Jaw amps and lead microamps are different measurements

Both meters measure AC and DC amps with their jaws. The CL390's 200 µA DC function instead uses test leads connected in series, according to its manual; its instructions prohibit more than 200 µA on that function. It is not a general-purpose amp input through the leads.

That distinction explains the HVAC pick. Fluke's HVAC clamp manual identifies DC microamps as a flame-rod test function and directs technicians to the heating equipment's documentation for the desired value. Our HVAC recommendation applies that task requirement to Klein's documented functions.

For jaw measurements, the CL710 manual specifies a single conductor, rather than a cable containing both live and neutral wires. It identifies a line splitter as the accessory for that situation. Follow the meter and equipment manuals; the clamp meter vs multimeter guide covers the broader tool choice.

Small current: resolution, accuracy and zeroing

The CL390's 40 A range resolves 0.01 A; the CL710's 60 A range resolves 10 mA. Those are the same display increment. The CL710's extra display counts therefore do not provide a finer lower-range current step.

The manuals specify lower-range AC/DC current accuracy as ±(2.0% of reading + 9 digits) for the CL390 and ±(2.0% + 8 digits) for the CL710. “Digits” means increments of the least significant displayed digit, added to the percentage allowance. At small readings, that allowance matters: display resolution is not a promise of equally small measurement error.

Klein explicitly gives the CL390 a 0.3 A AC/DC minimum measurable clamp current. The CL710 current specification table does not supply an equivalent minimum. A 10 mA display step alone is insufficient evidence that it measures a load that small accurately. For small battery-drain work, choose an instrument whose specified low-current performance fits the task.

Both manuals describe DC zeroing to subtract a displayed offset before a current measurement. The CL710 manual requires repeating the procedure if the DC current range changes. The CL390 manual adds an easily missed restriction: do not use DC current with a magnetic hanger attached, because the magnet can interfere. Follow the relevant manual's zeroing instructions.

Also keep the frequency specifications separate. Both manuals give 50–60 Hz for AC clamp-current specifications and 45–400 Hz for AC voltage. Do not apply the wider voltage bandwidth to jaw-current accuracy. These are Klein's stated limits, not measurements by thisMETER.

LoZ and CAT markings: read the limits together

Klein describes the CL710's LoZ mode as a way to identify and eliminate ghost or stray voltages. It is a distinct voltage function, with its own accuracy specifications in the manual.

The same manual defines CAT III around the distribution part of a building's low-voltage mains installation and CAT IV at its source. The CL710's markings are CAT IV 600V / CAT III 1000V; the CL390 is CAT III 600V. Match both the category and voltage to the work, and follow the lead-shield requirements in each manual. Leave panel and service-equipment work to a licensed electrician.

Both have non-contact detection, but Klein warns that voltage may still be present when it gives no indication. Treat NCV as an indication feature, not proof that a circuit is safe to touch.

Variants, boxes and nearby model names

Check the exact model and accessory list before ordering:

• CL390 standard package: Klein lists a carrying case, test leads with CAT III/CAT IV caps, a thermocouple, instructions and three AAA batteries. The magnetic hanger is optional.
• CL710 standard package: the specification list includes right-angle input test leads, a storage pouch, instructions and three AAA batteries. The thermocouple conflict above is a reason to use the documented functions, rather than the accessory bullet, as your buying criterion.
• CL810: a separate meter, not a CL710 accessory bundle. Its official specifications include DC microamps, temperature, LoZ, inrush measurement and an integrated worklight. A lighted CL710 dial does not supply those functions.
• CL380: an older model. Klein's CL380 page says it is no longer in production and identifies the CL390 as the newer model. Check the model printed on the meter when comparing bundles.

Buying guide: what switching actually changes

For an existing CL390 owner considering the CL710, the documented changes are:

• Yes: Gain LoZ and an illuminated dial
• Yes: Gain higher current and voltage ranges and higher CAT markings
• No: Give up documented DC microamp and contact-temperature functions
• Partly: Check conductor fit: the CL710 has the smaller specified jaw opening

Keep the CL390 if temperature and microamps are the functions you would otherwise have to replace. Choose the CL710 if those are covered and LoZ or its electrical ranges fill a real gap. If you need both collections of functions in the same instrument, compare the CL810 before buying either.

How we choose

This comparison uses Klein's official product pages, the manuals linked from those pages and its clamp-meter selection guide. We checked function lists, range tables, included accessories and specific operating warnings, and retained the document conflicts that could change a buying decision. Fluke's manual supplies the application context for flame-rod microamps. We have not physically tested these meters; accuracy and ratings are manufacturer specifications. See How we choose and How we measure for the site's approach.

Verdict

Buy the CL390 for its microamp and temperature functions. Buy the CL710 for LoZ, higher electrical ranges and its CAT markings. Existing CL390 owners should treat the CL710 as a change in capabilities: confirm which functions your work needs before replacing the meter.