GTC CM100 1 mA to 100 Amps AC/DC Low Current Clamp Meter by General Technologies Corp

Great milliamp meter for DIYing a vehicles electrical system/battery drain. Measurements are consistent and accurate. Easy to use. Money well spent!

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.

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.

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.

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.

This meter is easy to use and works well. Happy with my purchase!

Unit failed 2 weeks into use. Video load takes forever, unit has false readings and doesnt even work on oms setting.

I have several clamp on meters for dc measurements that are bad to awful, the last being a General Technologies CM100. My CM100 measured voltage with an error, has now stopped working for DC current, was unstable in measuring DC current when it was working, and had a small hole for the cable limiting me from measuring my inverter current in a 4/0 cable. I just bought a Voltcraft Current Clamp Meter VC330 (a German instrument) that feels well made and so far is working great at less than 1/3 the price. The VC330 will clamp on a 4/0 cable.