The Best Clamp Meters Under 100 Dollars — Buyers Guide, Review, and Comparison

CAT Safety Rating

Undoubtedly, the most important factor when differentiating affordable clamp meters.

For an in-depth explanation, check out my complete CAT Safety Rating 101. However, in brief, this specification indicates the loads that your clamp meter can handle, as explained below:

CAT I — Portable electronics such as cell phones and tablets.
CAT II — Mains-wired appliances like drills and refrigerators.
CAT III — Three-phase systems, for example, factory lighting.
CAT IV — High energy sources, such as overhead wires and mains boxes.

Therefore, when purchasing your ideal unit, check that the CAT safety rating equates to your planned projects. Remember that these machines are downward, not upward, compatible — a CAT III machine is fine to use on CAT I and II systems, but a CAT II clamp meter cannot test CAT III circuitry.

Ok, strictly speaking, that’s incorrect. You could use a smaller rated unit on higher loads — but you run the serious risk of blowing your clamp meter, suffering an unpleasant electrical shock, or dropping down dead.

You can buy CAT II-rated meters, but their price point is so similar to CAT III machines that you should go for the higher grade machine — as it will offer increased versatility for future projects.

Hence, for the DIYer and casual user, I suggest opting for a three-phase compatible unit like the Extech MA445 — and for light contractors and serious amateurs, the sub $100 Klein CL600.

TRMS Technology

A feature of all premium machines, but not of their more affordable cousins.

In short, TRMS-grade clamp meters offer higher testing accuracy than their standard RMS counterparts. For a detailed exploration (including some heavy yet accessible physics) take a look at my What Does RMS and TRMS Mean? article.

The truth for the casual user and DIYer is, you don’t always need it.

If your multimeter projects are no more adventurous than testing battery charge, troubleshooting broken connections, and trying to fix Little Jimmy’s remote-controlled car — it’s overkill, opt for a standard RMS meter such as the IDEAL 61-744. However, if you deal with mains wiring, printed circuit boards, or resistor replacement — precision is essential, so go for a TRMS unit like the Klein Tools CL380.

Temperature Testing

A nice feature, but like the TRMS tech above, it’s not crucial for all users.

Utilizing a thermoprobe — typically as a removable attachment — temperature testing clamp meters allow you to investigate heat levels in engines, microchips, air-con units, and circuit boards.

For many users, this is invaluable — such as in pro or hobbyist automotive and HVAC work. But, if you simply want to search for short circuits or check your third-party Chinese-branded lithium battery is suitable for your laptop — it’s pointless.

If you do need a temperature testing tool — check out the size of the heat range it offers. Some machines measure up to a limit of 752 degrees Fahrenheit — exemplified by the Fieldpiece SC260. Others can scrutinize up to an eye-watering 1832 degrees Fahrenheit, like the Klein Tools CL380.

Illumination

Depending on your electrical projects, you may not always be working in ideal light conditions.

Investigating sub-floorboard wiring, checking basement junction boxes, and troubleshooting broken patio flood lamps at night can lead to issues reading your clamp meter.

So, if your work entails poorly lit environments, consider a machine with a backlight — illuminating the LCD screen and permitting you to make accurate recordings in dim conditions. A perfect example of this is the Klein CL600.

Some machines go one step further. The TRMS boasting Extech MA445 features an in-built flashlight in addition to a backlight. Hence, not only can you easily discern the LCD screen, you can accurately position your testing probes without requiring a secondary light source.

Memory and Storage

Memories…we simply choose to forget — so sang Barbra Streisand in The Way We Were (Columbia Records, 1973).

Undoubtedly (maybe), Streisand was indicating the difficulty of accurately recalling her clamp meter readings after addressing the troublesome issues of her malfunctioning microphone.

What Babs needed was a machine with a memory feature — such as the Klein Tools CL380. This enables you, at the flick of a button, to display the last measurement taken, as well as the minimum and maximum levels achieved. Thus giving you the time to precisely identify the issue without having to remember what the LCD screen detailed.

Interestingly, Streisand frequently referred to DIY in her hit singles, including:

• Evergreen (1976) — examining the color scheme of Bosch tools.
• Guilty (1980) — expressing her remorse at spending all her rent money on a rotary hammer drill.
• What Kind of Fool (1981) — after buying an HVLP spray gun but not owning a suitable compressor.
• Papa, Can You Hear Me? (1984) — when testing her ear defenders on her father.
• Send in the Clowns (1986) — her bad experience with cowboy contractors.*

  *all the above may not be strictly accurate.

Battery Saving

You know how sometimes you’re lying in bed, and the weirdest thoughts enter your mind? This happened to me a couple of weeks ago, when at around 2.00 am, I began wondering why clamp and multimeters don’t come with a corded option — they’re all battery-powered.

Then it dawned on me — if you’re trying to figure out why your mains electricity isn’t working, it’s a bit pointless plugging in your multimeter. But then, my stream of consciousness began to drift to the equally ridiculous question of why these machines use disposable alkaline batteries, and not reusable lithium-ion. And, of course, the answer is if your electricity supply is screwed, you can’t recharge the cells.

This is the bedroom excitement of too many years of marriage.

Anyways, back to my point. As clamp meters are driven by two or three AAA one-use batteries — power saving and monitoring are crucial. You really don’t want to be mid-project surrounded by bare leads, the meter failing due to lack of juice, and then having no idea whether touching that red wire will result in an electric shock.

Therefore, I recommend going for a machine that features a low-battery warning light — such as the Extech MA445. Alerting you to dangerously low residual energy, you can then opt to make your circuit safe before the cells fail completely, or replace them with full batteries.

Furthermore, it’s worth considering a clamp meter with auto-shutoff — like the IDEAL 61-744. This feature deactivates the unit when left idle — saving you valuable battery life.