




⚡ Clamp the Current, Own the Circuit!
The GTC CM100 is a modern, battery-powered clamp meter designed for professional-grade AC/DC current measurement from 0.001 to 100 amps and voltage readings up to 600 volts. Its compact jaw size and rapid sampling rate make it ideal for diagnosing parasitic battery drains and tight automotive electrical spaces. Equipped with peak/data hold, continuity alerts, and a complete accessory kit, it’s a reliable tool for precise, on-the-go electrical testing.




| ASIN | B001TCWL1E |
| Best Sellers Rank | #135,111 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #90 in Clamp Meters |
| Brand | GTC |
| Brand Name | GTC |
| Color | Grey with Yellow Clamp |
| Customer Reviews | 4.4 out of 5 stars 302 Reviews |
| Global Trade Identification Number | 00833303000282 |
| Included Components | CM100, 2 batteries, User's manual, Test leads, Soft carrying pouch |
| Item Dimensions | 11.4 x 5.7 x 2.5 inches |
| Item Height | 2.5 inches |
| Item Type Name | Current Clamp Meter |
| Item Weight | 0.95 Pounds |
| Item dimensions L x W x H | 11.4 x 5.7 x 2.5 inches |
| Manufacturer | General Technologies Corp. |
| Measurement Type | Ammeter |
| Model | CM100 |
| Power Source | Battery Powered |
| Specification Met | Gtc |
| Style | Modern |
| Style Name | Modern |
| UPC | 833303000282 |
| Warranty Description | 1 YEAR EXCLUDING BATTERIES |
G**R
Works well, very accurate
Great milliamp meter for DIYing a vehicles electrical system/battery drain. Measurements are consistent and accurate. Easy to use. Money well spent!
G**I
Perfect for Hunting Automotive Ignition Off Parasitic Battery Drains
I give it 5 Stars because of the purpose it serves for the price one pays. DC clamp meters are not usually low cost and if they are they are usually less than stellar. This meter is perfect for chasing after automotive ignition off parasitic battery drains, AKA Dark Current". The small form factor helps for getting into tight places. There are other reviews here about the characteristics of this meter such as its sensitivity to ambivalent temps. I find if I'm working under a hot hood, as the meter warms up if held under there long, just re-zero it every once and a while and clamp again. If I am going to check current on a given cable I will hold it beside the point where I am going to clamp and zero it first. Especially if near a battery or other live wires or junctions so any magnetic fields can be taken into the factor. Its easy enough to just press a button twice. There is a very detailed Utube review by Pretty Boy 0508.
M**E
accurate and fast response time
Very accurate down to 1ma level. When measuring the DC current combined with peak function, you need follow the current flow direction mark on the clamp side, if flow direction reversed, then you will always get "0" as peak value because the real peak value is recorded as negative,then you will think the peak funtion is not working.( this is also true for dc vlotage measuremet with test lead) Its response time is quick. The zero function work fast and accurate. Only one issue: the DC voltage measuremet get 0.2 volt difference (less) in negative reading if you reverse the two test leads to measre.(like 1.5 v and -1.3 v which shouel be -1.5 v) I tried two meters and they act the same. I may live with this and remember to keep the low DC voltage measurment in positive side. Amazon even send me the new second meter before I return the first one. Definitely a great buy, if you wnat measure low accurate dc or ac current with clamp, and need peak function.
K**Y
Great for Automotive and DIY projects
I am a seasoned electronic tech and avid Do It Yourselfer. I tested the accuracy of the clamp-on Amp meter and it is quite good for the price. I have already used it on some automotive projects and look forward to using it on my future electronic projects. DC clamp-on current meters are great for when you want to measure Amperes flowing through a wire but don't want to cut it to insert a "classic" Amp meter in series. The Ohm and Voltmeter ranges on this meter leave a lot to be desired. Don't buy this thing if you need anything but the basics on resistance and voltage measurements. That said, the clamp on DC Amp meter is well worth the price of the entire meter, even if you never use the Ohms and Volts scales.
D**F
Truly capable of demanding instrument performance, the GTC CM100 proves itself repeatedly.
My purchase was a slightly used one, but proved to be well worth the expense. GTC has engineered a truly fabulous precision instrument in this clamp meter capable of accurate measurements down to 1 mA, in either the AC or DC mode. An automatic zero feature keeps the jaws calibrated even when the currents being measured are minuscule. Construction is solid and convincing to the user. A storage pouch and a set of test leads are included. Measurement of parasitic currents are easily made with this AC/DC clamp meter. That was my primary reason for making this purchase. Of course, resistance and voltage measurements are also possible, but the instrument is touted for its low level current measurements.
J**Y
Good value for the money...
I almost didn't buy this meter based on some of the negative comments. I am glad that I did. I needed a small meter that was able to read milli-amps... and this meter was listed as one. I read comparisons to Fluke meters (Which I also own) and decided that if it was really bad I could always return it. I am NOT returning this. DC Amp readings... you have to zero the meter and watch the direction of the clamp... works perfect for me. The size of the opening in the clamp. It's a half inch... it's made that small for a reason and works well in tight areas. The voltage readings and ohm reading work as normally expected. Perfect. As for the quality of the build of the meter... It isn't a hammer... It isn't a pair of pliers...If you use it as intended and treat it for what it IS... it will last. I would buy this meter again in a heart beat...
F**Z
Quality control failed me.
Unit failed 2 weeks into use. Video load takes forever, unit has false readings and doesnt even work on oms setting.
A**R
Only Clamp Amp meter that actually works for DC Amps Accurately
Perfect to find parasitic power draw for automotive trouble shooting. The only thing that would be great that could be added other than the peak, and hold function would be a DC averaging function. Where it not only records the highest value but average as well.
Trustpilot
3 days ago
2 weeks ago