Klein CL800 Review

Editor Rating: 4.7/5

Great Product

Klein Tools CL800 Review

Reviewed by: Timothy Henderson

Last modified: May 27, 2023 @ 11:07 am

  • Design
  • Functionality
  • Price

Klein CL800 Review Summary

Taking affordable clamp meter functionality to the max — the Klein CL800 is a high-performance electrical circuit tester that lacks the high price tag of comparative trade grade units.

Focusing on the serious home user and pro-contractor, this machine boasts all the expected capabilities to scrutinize voltage, continuity, capacitance, current, and resistance, but with additional facilities for the project-specific operator.

With a low-impedance mode, the CL 800 eliminates annoying and troublesome ghost voltages — increasing job accuracy. And, with a temperature testing thermoprobe, the tool will appeal equally to automotive enthusiasts and HVAC engineers.

TRMS tech and auto-ranging offer precision combined with downtime-saving practicality. And, rated for CAT IV environments, you can safely use this meter on high-energy loads such as utility transformers and pole-to-pole wiring.

This machine comes from the Klein Tools stable, a US brand with over 160 years of experience in equipment manufacture. The CL800 is a step above the similar CL700 model, that offers comparative capabilities, but cannot test DC voltage with the clamp — an ability offered by the CL800.


  • Weight – 12.5 ounces
  • Voltage – 1000 volts
  • Current – 600 amps
  • Safety Rating – CAT IV


  • Low impedance.
  • 1.38-inch jaw.
  • Auto-shutoff.


Non-contact voltage testing.
Arrives complete with batteries.
Low impedance mode.
CAT IV rated.
TMRS technology.


Less than durable testing leads.
Relatively weighty.

Features and Benefits of the Klein Clamp Meter CL800

Designed with the trade pro and serious amateur in mind — yet remaining pleasingly affordable — the CL800 Klein Clamp Meter appears initially to be a purchase-worthy machine.

Yet, when we get down into the details, is this unit as impressive as first impressions indicate? Time to scrutinize the CL800.

Low Impedance Mode

To misquote Renee Zellweger in Jerry Maguire (1996) — you had me at low impedance. Guys, this is definitely a serious contractor-level unit.

If you work in the electrical business, you know there are times when your clamp or multimeter indicates the presence of a voltage — but it has no business being there. Your testing subject has no mains electrical supply, battery connection, or includes zero capacitors — yet still your detecting volts.

It can be a nightmare trying to locate the issue within the machine, especially when the reading occurs due to outside interference — known as ghost voltages.

These spooky anomalies occur when live electrical machines or wiring are in close proximity to the circuit you’re investigating. This can create capacitance between the live and supposedly dead electricals, giving the impression of voltage — screwing up your investigation.

Switching the CL800 Klein into low-impedance mode eliminates these spectral readings — allowing you to accurately scrutinize your target circuit.

TRMS Technology

In keeping with its pro-grade status — it’s perhaps no surprise that the Klein Tools CL800 features TRMS, or True Root Mean Square, technology. This promises more precise circuitry analysis than standard RMS machines — by checking wave frequency discrepancies instead of just peak current or voltage.

This level of accuracy is crucial if you’re dealing with electrical systems that demand exactitude — such as PCBs and microchips, where even small anomalies can burn out the circuit or component.

If you want a more in-depth explanation of TRMS and RMS — and what it means for your multi or clamp meter — check out my complete guide here.

Temperature Testing

With an ability to measure heat levels — the Klein CL800 Clamp Meter should appeal equally to automotive enthusiasts as HVAC engineers.

Capable of determining temperatures between -14 degrees to 1000 degrees Fahrenheit with an included thermoprobe attachment, you can use this machine to check out engine running temps, condenser efficiency, and heating element condition.

Or, if you have no interest in cars or air-con machines — you could stab the clamp meter into your Thanksgiving turkey to see if it’s sufficiently cooked.


Boasting intelligent auto-ranging tech, the CL 800 removes the time-wasting experience of fiddling with buttons and dials to set readout range. Automatically detecting whether the current, voltage, or resistance should be displayed in tens, hundredths, or thousandths, you save valuable downtime — crucial if you’re a trade pro working to a tight schedule or have a demanding client that wants their electrical work completed yesterday.

Furthermore, if you’re something of a newbie to the clamp meter world, it negates the need to have any prior knowledge of circuitry metrics and measurements.

CAT IV Rating

Receiving an electric shock can severely hamper your enjoyment of circuit testing — or kill you on the spot. Sure, as a kid, you’ve licked a few batteries — however, the low voltage and current of these cells deliver nothing more than a funny tingle. But, stick your tongue on an overhead utility wire, and you won’t be around to describe how tingly that experience was.

Clamp meters have CAT ratings, this indicates the energy load the machines can safely handle, without exploding in your hands and causing you injury, or death. Naturally whatever the CAT certification of your clamp meter, licking live circuits isn’t advisable — but higher-grade machines do provide greater shielding when used correctly.

The CL800 Klein Tools Clamp Meter is rated to CAT IV — permitting the safe use of the unit on overhead cables, mains transformers, and utility junction boxes. This is in contrast to CAT II units that are limited to plug-in equipment such as irons and drills, and CAT III that can investigate three-phase industrial systems.

Want to know more about CAT certification? Take a look at my What Are CAT Safety Ratings article.

Included Accessories

Seen the movie Batteries Not Included (Amblin Entertainment, 1987)? No? It’s a heart-wrenching story about a guy who receives a clamp meter as a Christmas present, only to discover that it doesn’t arrive with power cells — meaning he can’t use the shiny new tool as he has no spare batteries in his house, and the stores are shut for the holiday period.*

However, if he’d received the Klein Tools CL 800 instead of the cheap dodgy unit that his wife purchased for him, the film would have been completely different. That’s because the Klein arrives with two AAA power cells, allowing you to use the machine straight outta the box.

Additionally, the machine also arrives with:

Soft carrying case.
41-inch testing leads.
Thermoprobe attachment.

*for the record, Batteries Not Included (Amblin Entertainment, 1987) is actually about tiny extraterrestrials that save a threatened apartment block from redevelopment. Watch it, it’s very sweet.

Additional Features

Over and above the key trade-welcome characteristics described above in this Klein CL800 review, this machine also boasts:

  • 6.6-foot drop resistance — for clumsy operators.
  • Low battery indicator — preventing malfunction mid-project.
  • Auto-shutoff — saving valuable battery life.

Klein Tools Clamp CL800 Meter Specifications

Klein CL800
Weight12.5 ounces
Jaw Size1.38 inches
Drop Protection6.6 feet
Voltage1000 Volts AC/DC
Current600 Amps
Highest Safety RatingCAT IV
Size9.09 x 1.55 x 3.81 inches
Batteries2 x AAA
Auto-Power OffYes
Diode TestingYes
Capacitance6000 µF
Resistance60 MΩ
Temperature Range-14 to 1000 degrees Fahrenheit

What Do Users Say About the Clamp Meter Klein Tools CL 800?

For me, the CL 800 from Klein is a trade-grade machine offering high-end circuitry testing specifications, but at a price suitable for the serious amateur and budget-focused professional.

But, is my enthusiasm blinding me to this unit’s obvious faults? In order to ensure a completely unbiased review, I researched the owner’s opinions — to discover what guys using this meter on a frequent basis thought about its functionality and practicality.

Reassuringly, the testimonials were, in the main, positive. Users of the Klein applauded its low-impedance mode, welcomed the industry-grade CAT IV rating, and praised its accurate TRMS tech.

Sure, as always in life, there were some naysayers. One trade-pro felt that the included testing leads wouldn’t stand up to extreme hardcore use — while a disgruntled DIYer was of the opinion the LED warning lights were too dim to alert of current issues in bright conditions.

That said, all owners concurred that the Klein Circuit Tester CL800 was a trade-ready unit that offered a greater price-to-feature ratio than higher-end machines.

Alternatives to the Klein Tools CL 800 Multi Clamp Meter

Despite all its benefits, it’s possible that the CL800 from Klein Tools isn’t stimulating your clamp meter appetite. As I’m aware that it will not be suitable for all users, I’ve put together three alternatives that may address you and your project demands more adequately.

Fieldpiece SC260

Should the temperature testing facility of the Klein machine appeal — but you feel that its heat range is insufficient for your needs — consider this unit instead.

The SC260 boasts a remarkable temperature scrutinizing feature up to 1832 degrees Fahrenheit — 832 degrees higher than the CL800. Additionally, it matches the Klein unit in featuring TRMS technology and auto-ranging.

  • CAT III rated as opposed to the CAT IV of the CL800.
  • Similar price point to the Klein.
  • Includes mounting magnet — not a feature of the CL800.

Extech MA445

Should you demand TRMS technology and auto-ranging as featured on the CL800, but are concerned about the Klein’s practicality in dimly lit conditions — check out this clamp meter.

The MA445 incorporates an in-built flashlight — allowing you to illuminate your target project without the use of a secondary work light. While lower-rated than the Klein with CAT III certification, it’s significantly lighter on your wallet.

  • 600-volt rating — opposed to the 1000 volts of the CL800.
  • Tests to 1832 degrees, in contrast with the 1000 degrees of the Klein.
  • Unlike the CL800, it lacks a low-impedance mode.

Klein Tools CL380

If you’re a fan of the Klein brand, but would prefer a more DIY-focused machine than the pro-targeting CL800 — consider this unit.

The CL380 arrives with the renowned reliability of Klein tools, but omits the CL800’s contractor-specific features unnecessary for the home user — such as low-impedance, CAT IV rating, and 6000 µF capacitance.

  • Lower price point than the CL800.
  • Rated to 600 volts as opposed to the 1000 volts of the CL 800.
  • Requires 3xAAA cells, in contrast to the 2xAAA cells of the CL800.


Delivering premium-grade testing capabilities, yet without the high-end price tag, the CL800 from Klein Tools is an impressive unit for the serious DIYer and trade pro.

Its low-impedance mode eliminates annoying ghost voltages, while its TRMS tech promises reassuring accuracy. Rated to CAT IV, it’s suitable for high-energy utility loads, while auto-ranging saves downtime and makes the tool usable by circuitry novices.

Sure, this unit isn’t going to suit all tastes. For many casual DIYers and amateur electricians, the unit is seriously over-specced. And, being concomitantly weighty and lacking a rear mounting magnet — it could become unwieldy in situations without the facility to set the machine down.

But, if you want a tool that can compete with the big boys without wrecking your bank account, I suggest you consider the Klein CL800.

Klein Tools Clamp Meter CL800 FAQs

Q: What Is the Klein CL800 Price?

The Klein CL800 is a highly affordable clamp meter yet boasts remarkable pro-grade functionality, including TRMS technology, auto-ranging, and a CAT IV rating. To check out the current cost of the Klein CL800.

Q: What’s the Difference — Klein CL800 v CL700?

The CL800 and CL700 models are remarkably similar — both machines are CAT IV rated, incorporate a low impedance mode, and feature temperature testing. The key difference is that the CL800 can test both AC and DC current with the clamp, whereas the CL700 can only scrutinize AC systems.

Q: Where Can I Buy the Klein Tools CL800?

The Klein Clamp Meter Tester CL800 is a trade-ready machine that includes TRMS tech, auto-ranging, and has CAT IV safety certification. You can get your hands on this unit by clicking here.

Q: Where Can I Get the Klein Tools Clamp Meter CL800 Manual?

The official Klein Tools website offers a plethora of user guides and instructions for its testing machines. For rapid access to the Klein CL800 manual.

Q: What Batteries Does the Klein MultiMeter CL800 Use?

The Klein Clamp Meter CL800 requires two AAA batteries. Pleasingly, these are included with the unit purchase.

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