Multimeter Review / buyers guide: GTC CM100 1 mA to 100 A Low Current Clamp Meter

This is a review of the GTC CM100 1 mA to 100 A Low Current Clamp Meter
You can buy it here: astore.amazon.c...
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There is a BK Precision equivalent - Mini AC/DC Clamp Meter Model 316: www.bkprecision...
The 316 is the perfect Clamp Meter for many electronic applications. Because this meter was designed to measure smaller amounts of current it is ideal for quick non-intrusive current measurements.
Auto power off
4 Digit LCD display
Low battery indicator
0.49" Clamp opening
Overload protection
AC/DC Amp ranges 10A, 80A & 100A
1mA (10A range) & 10mA resolution
Measures current between 5% to 100% full scale
Measures AC/DC Volts to 600V
Measures resistance to 10K ohms
One year warranty
GTC 1 mA to 100 Amps AC/DC low current clamp meter is designed to accurately measure current, current leaks (parasitic draws down to 1mA) and electrical loads from 1mA to 100 amp AC/DC and voltages from 0 to 600 AC/DC. The small diameter (½ inch or 13mm) and narrow jaw makes it ideal for use in confined spaces and on small gauge wires. Other features include resistance measurement functions, audible continuity test, display hold and peak detector.
Product Details:
Amazon Sales Rank: #4437 in Automotive
Color: Grey with Yellow Clamp
Brand: GTC
Model: CM100
Features:
AC/DC current measurement from 0.001 up to 100 A. which makes it a great tool for measuring parasitic draws and AC/DC voltage measurement up to 600 volt
Small jaw: 1.2 inches (W) x 0.53 inches (D) (300x13.4millimeters) with clamp opening up to 1/2 inch (12.5 millimeters)
Peak and Data hold functions with one rotary switch operation
2 readings per second sampling and continuity check with audible indicator
Test leads soft carrying deluxe pouch and batteries included

[@mjlorton]

Yes...I spotted them while I was editing the video...will have to have a fiddle.... Thanks for the feedback.

[@mjlorton]

Yes, it would be a useful to test / look for parasitic draw from a battery. It uses 2 x AAA 1.5v batteries. I have not tested any other low current clamp meters that I could refer to. Cheers, Martin.

[@mjlorton]

Very good point! That's worth showing folks as repeatability is certainly an issue. I'll see if I can setup a quick demo for that. Thanks for the post.

[@mjlorton]

The one I know about which apparently was a break through for PCN trouble shooting tools is the Fluke 773 Milliamp Process Clamp Meter.

[@mjlorton]

Hello, Yes it should easily fit. The clamp has a 13mm diameter. Cheers.

[@dave1121]

This was super helpful and thank you for doing this in-depth review. I've been looking at clamp ammeters on Amazon for awhile and the prices are all over the place. I need one for automotive parasitic draws. I came across this video via the Amazon product listing, thanks!

[@mjlorton]

Aaaah...it looks like a multimeter can be used as a reference for current and perhaps other measurements. I noted the current reference of the Fluke so I can check it over time to see if it is stable. If it does seem viable I'll post a video about it.

[@gregsullivan7408]

Quite amazing performance for the money! Every few years I have a half hearted look around for accurate low current DC clamp meters that I can afford, always expecting to be disappointed. This time I found this review, and WOW. :)

[@mjlorton]

No, you'll note in the video I connected it through my HP as well to ensure my TTi was within 1 or 2 counts.

[@BVHVVH]

Just the exact information I've been looking for on this great low current clamp meter. Just picked one up because of your review. Less than $150 to my door. Hard to beat.

[@mjlorton]

Yup...and if it holds steady to even four decimal places it would be great.

[@mjlorton]

I'm sure Amazon can deliver... ;-) Thanks for watching.

[@MH-on8ol]

Thanks, I was looking for a meter to chase low dc amp leakage in vehicles 12v systems. I saw many that were very limited and some very expensive. I just ordered it and hope it holds together.

[@mjlorton]

My pleasure Keith. Cheers, Martin.

[@mjlorton]

I certainly appreciate that...I have the same issue getting things here...

[@mjlorton]

My pleasure, thanks for the feedback.

[@Viokehd]

Thank you for the excellent review!! This is exactly what I was looking for; a CLAMP meter that could measure LOW DC Amps. It's affordable too! Your perfect review answered ALL my questions. Thank you very much.

[@josephmalysa4964]

Thanks very much for the informative review. I purchased the GTC CM100 and tried it out. For testing Lithium ion battery/charger performance, it worked well. I used a Cadence 8000 to charge and discharge a lithium ion battery, therefore I knew the current. When I used Cadex to discharge 30mA, 75mA and 1.1 A the CM100 read 25mA, 84mA and 1.08A, pretty good for a $140 meter. So far, It is pretty stable. I have a holder for the battery wire to keep it perpendicular to the clamp. I also zero it before use and after the measurement is taken pull the power to the DUT and the reading should change back to 0, if not then I have a feel for the amount of drift.

[@Stealthsilent1337]

in 2023 the meter costs 250$, from what I read it's ~.003mA precise and ~.010mA accurate

[@mjlorton]

Thanks, the GTC CM100 is a very good toll for automotive work.

[@mjlorton]

Sean, you would need to add it to your Amazon "cart" and select the shipping type to get an idea. Also...even though these things should be duty free allow for a couple of hundred Rand in possible duties. Another option, Comtest have an online site that sell the BK Precision version. Google "Test Instruments Africa" - product code:- BK-316 price: Price:R1548.27 Cheers, Martin.

[@mjlorton]

Thanks for the input and feedback.

[@mjlorton]

Thanks for the feedback and the sub!

[@mjlorton]

The reading should still be the same, it's just the polarity that will change for DC readings.

[@Orcinus24x5]

What is the purpose of the "0.29882 mA" label on the Fluke meter?

[@SjoerdBeukers]

9:04 there are actually 4 pots on the board ;) Thanks for another great video martin!

[@dtrrtd774]

Would have been nice if it had the ability to hook up to an oscilloscope, if it were capable of dynamic measurements.

[@ebbyt00]

would you Please recommend clamp meter that would have high resistance reading capability around 1000 MO

[@YogendraSinghRawat-bv3cv]

Please review its ac current measurements

[@dtrrtd774]

Is there any other low priced current clamp meter that has outputs to enable connecting to a scope along with the built in display for current measurements? I have a high range current clamp with no display, but was considering adding a low range clamp like this, if it had outputs.

[@r.j.krieger7666]

Good review but what about the high end of the meter amperage? If using for automotive the higher draws would have been helpful as well.

[@generaltechnologiescorp.3852]

The CM100 can measure up to 100 Amp AC/DC. However, GTC also offers the CM600 which can measure up to 600 Amps AC/DC, and the CM1000 which can measure up to 1000 Amps AC/DC.

[@SeanBZA]

How do i get access to the forum? Registration page leads to an email saying wait for a admin to allow.........

[@rodneyrafuls5899]

Hello sir, I bought this meter hoping to read milliamps signals from wire guidance systems but the meter was not able to read a 240 ma signal at 6.25 kilohertz, is the frequency too high for the meter?? Thanks in advance!!

[@241mrmark]

Looking forward to watching this one as a channel subscriber. I need a means of measuring Low res and dc amperage measurement for auto repair of a parasitic discharge, for boiler output dc measurement/dc stunning a protective devices (RCBO) ability to trip.

[@louiemunoz2753]

Can you use it with a graphic meter?

[@AutobahnWest]

Martin, do you think the clamp is big enough to put around a vehicle battery cable? I am interested in purchasing this meter to test for amperage draw on vehicle when shut off (parasitic load). But I can't tell how large the clamp is. Thanks,

[@SeanBZA]

Would like one, perfect for industrial use. Nice current ranges for machinery, and will work well on most industrial logic. 1 decimal on voltage is OK, wonder how the overload capacity is though, will it survive 380V on ohms range? For me the major use would be the current probe, the voltage and continuity are just a bonus, as i can use other meters for that in conjunction with this one. How much in ZAR delivered?

[@rapidfiredm]

This is identical to the BK Precision 316 sells for $150 cdn perfect for fire alarm which use 12v sealed lead acid and emergency lighting 6volt SLA both of which can have low amp 4.5Ah 7 Ah but can go up to 75mps rarely more than that. great accuracy for this. Most techs use meters designed for high AC currents which is inaccurate for low current

[@AlexTechWiz]

You saved me 40 bucks, thanks a lot Pal!

[@geoeconomics5629]

Uni-t 219DS 1000 amps clamp meter can read accurately below 100 mA

[@tejeswarareddykota5105]

how can I measure 100amp battery with any sort of means I mean like multimeter

[@SeanBZA]

Tried it and it works thanks. Thumbs up!

[@AutobahnWest]

13MM does not seem large enough to me, some battery cables are almost as large as a quarter. Other than size this would be a useful tool to measure amp draw from a battery with the vehicle off, correct? Does it use a 9v battery to power on/ off? Any other clamp meters that you know of that are low range that have a slightly bigger clamp that are good? Or maybe I should put together some kind of current shunt. Thanks

[@wingerrrrrrrrr]

The positive side battery cable is usually split in two, with the thick wire used only for the starter, and a thinner side for the general electrical circuit supply. While it won't fit around the thick wire, parasitic draws likely won't be coming from the starter. The other side would be what you'd hook up to for that.

[@jandean1317]

Another excellent review. A colleague tested the CM600 and found that it worked well on squarewave pulsed direct current but not on half-sine PDC. Does the CM100 accurately measure half-sine or quarter-sine pulses? I'm interested in peak current and in peak voltage. Will it accurately measure peak volts and peak amps for capacitor discharge (exponential decay) pulses? Thank you for the excellent reviews. Very helpful.

[@luretrixster]

Excellent as always :) Thank you, I will buy this meter because of you

[@themotofixery]

How would this compare to the Fluke 365 Detachable Jaw True-RMS AC/DC Clamp Meter? Im trying to decide witch one to purchase for automotive and general use. I like the fluke brand, the detachable clamp, and clamp size/capacity but im not sure if they both have the same resolution. Im more concerned about small dc measurements. As I understand they both measure down to 1 miliamp?

[@sylkelster]

Late reply, but for anyone interested the fluke only has 100mA or .1A resolution, but is great other than that.

[@themotofixery]

@@sylkelster fantastic thanks!

[@bjjohns]

I am trying to find a comparison of this VS a Fluke 771. Any thoughts? I am really looking at the 4-20 ma process control ( we call it a control loop) range.

[@graememckernan8362]

Are you working on HVAC or the Shuttle $ for $ of Quality

[@RichardPNLing]

It appear to me that the pointed ring of this meter is most suitable for working under confined environment. It would be better if you could tell us what is the max diameter of the wire that can be measured.

[@generaltechnologiescorp.3852]

For the CM100 the max diameter of a wire that can be measured is 12.5 mm (1/2"). For the CM600 & CM1000 it is 25.4 mm (1").

[@AMGTOM]

Hi Martin, Nice review as usual, I would like to advice about which clamp meter will be suitable for Automotive use and tests. All the best, Amine from Algeria.

[@RaviSingh-xo7my]

bro i am gonna for buy Meco 1008 trms clamp multimeter. does it better then UNI-T UT 203 and others ? kindly tell me it's urgent?

[@JAKOB1977]

Weird that none of these two big-meter testing channels dont actually test the units that stand out on the electronic-stage. Let be honest there is one AC&DC low current clamp meter that is quite popular and been it for like 6 years and to an extent close to nothing else and everybody on EEV blog who get their hands on it, are quite impressive with the low current abilities 1ma and quality hence price and lack of drifting + modding and opening up way higher count 9999 and backlight timing etc etc. thrue EPROM flashing and thats the UNi-T 210E that cost around 30 bucks USD. (at least the one o picked up on eBay a month ago from China) plus you can mod it to oscilloscope reading etc and it got a quite potent NCV and TRMS and V.F.C abilities. Have you not tested that one mjlorton.? ( I know you can't test all, but at the end of the day there are some few meters that simply stands out and is ideal for the main consumer, hence price vs feature and cost surprisingly little.)

[@nareshnarasimhan9774]

Great review. Is GTC CM100 a " true rms" clamp meter ?

[@sepertude]

Fluke i30s is also good, it connect to the scope..

[@mjlorton]

Yup, I've done just that and posted pictures on my forum in the general section: mjlorton(dot)com Hope that helps.

[@Orcinus24x5]

Ahh, yes... I had forgotten that when in ohms mode, multimeters use a self-generated constant-current source through the resistor and then measure the voltage drop to calculate the actual resistance. Hmm, this might have some merit to it. *ponders*

[@andreyvasiliev614]

is it can to show MIN and MAX ?Thanks.

[@generaltechnologiescorp.3852]

Hi Imya, The CM100 doesn't show MIN, and has a "PEAK" function that can capture the MAX.

[@AutobahnWest]

I know it is a lot to ask but is there anyway you can try to clamp that bad boy around a vehicle battery cable. I haven't been able to verify anything and can't find one locally to look at. Your my only source of info at this point. :) Thanks,

[@generaltechnologiescorp.3852]

It should likely fit.

[@Matthias051]

Thank you so much again for this nice review video

[@raulbotero982]

Excelent video.

[@rockynix7731]

Can you measure dc current with it .

[@pg9112471]

Very thorough. Thanx

[@JohnUsp]

Good review, but you should also plug a good DMM to get the precise value.

[@edgardo8055]

Hey men mi clam quedo directa la pantalla

[@edgardo8055]

Se puede reiniciar

[@AlexTechWiz]

Que?

[@andypandyc]

thanks m8 . keith

[@DLTX1007]

Well for one reason, it might be your TTi PSU's that's out

[@DLTX1007]

Oops, didn't take notice. Ciao!

[@jeffreydeutsch7336]

I think you totally miss who the customer base is for this meter. Many buy it for chasing down parasitic current in cars. It has nothing to do with inexperience.This is not an uncommon problem and it can quickly run down the battery in a parked vehicle. Unplugging connectors to insert a conventional multimeter can be a nightmare. The form factor of this meter allows it to grab a wire in a tight space. At the moment I am trying to find out why the battery draw in my pick uo is 1.2 amps instead of the expected 30ma when it is parked. Taking an in line current reading at the battery is easy; following the wiring to it's source is not. The secondary features of the meter are of no interest to me. Nobody buys this for a primary meter. I own a Tektronix, later rebranded as a Fluke, for that. Even a bottom end multimeter is more convenient for voltage, diode checks, frequency, capacitance and resistance checks than this guy. It is a specialized meter, not a beginner's tool for people that are unfamiliar with their multimeters.

[@robertmccully2792]

Even i could understand.

[@mjlorton]

I've already approved your account so it should have mailed you. Try login, if you still have a problem email me: martin(@)mjlorton.com

[@rockynix7731]

Never mine just answered my question .

[@SjoerdBeukers]

make that 5 sorry