Good clamp meter for low DC currents

[J-R]

I say the video points out the differences between someone who is coming from the concept side vs. someone who is just trying to do a job and measure an unknown with their clamp meter.  So yes, some of the tests and conclusions are a bit questionable in the context of this thread, but you may still bump into those conditions in the field.  Who is right?  Maybe one solution is high-speed sampling, then perform any desired calculations such as averaging.

The bugs and lockups are disturbing though, especially at that price point.  They should have gotten a second unit to rule out a faulty device for some of the issues.

Overall, it's not looking too good for the CM11.  Limited functions, bugs/lockups, expensive...  But maybe some would still buy it for specific tasks.

[Martin72]

The bugs and lockups are disturbing though, especially at that price point.  They should have gotten a second unit to rule out a faulty device for some of the issues.

What bugs ?

One of the main problems is that you have to know what you are using what for.
For me, the matter was over when PWM signals or the simulation thereof were measured.
But that is beside the point.
We bought this current clamp because we wanted to measure small standby currents.
Before we could use this current clamp, we had to have it calibrated externally and the second one has now successfully passed this type of calibration.
I therefore only see two possibilities.
Either the video is largely rubbish, or the calibration carried out according to international standards is rubbish.
Due to the principle, I tend towards the former.

[J-R]

The bugs and lockups are disturbing though, especially at that price point.  They should have gotten a second unit to rule out a faulty device for some of the issues.

What bugs ?

Enter manual range mode, can't go back to automatic.  You have to turn it off and back on.
There is no display icon to indicate if you are in manual or automatic mode.
Min/Max function has various issues, such as showing OL when you open the clamp/stop current flow while in manual mode and it actually locks up the meter if you press hold while using Min/Max.
It generates a 102Hz signal back through the wire being tested while in DCA mode.
Over 30mA draw in DCA mode, which combined with the two AAA batteries means a very short runtime (maybe 30 hours).

I agree with you about the the flaws in the video.  They clearly don't understand a lot about what they are doing.  The point I was trying to make was all they know is when they try to take certain measurements, one cheap clamp seems to work and the CM11 doesn't.

[beanflying]

Looking for a cheapish DMM to leave in the Car toolbag so I was going to buy another 210E as I like the one I already have but the BT version of the Owon for singlehanded vehicle work might be handy and make for a decent second clamp meter if needed.

Anyone got a BT version care to comment? Yes I know BT has issues too but it is what it is.

[naiclub]

I use model 204A and it works well and is quite accurate. Used for almost 10 years.

[BILLPOD]

Anyone got a BT version care to comment? Yes I know BT has issues too but it is what it is.

I have recently acquired the OWON and have been comparing it with my 210e, and they are pretty much equal in accuracy, (DC current is all I  have been comparing).   However, the Owon has the bluetooth, which I love, and the android software is nice to use.   But, as with the bluetooth on any of my other meters, the range is poor, but better than my Mooshimeter.

[mzzj]

You really do have to consider ALL external sources of magnetic fields, but developing a technique and using the "zero" button has proven to give reasonably repeatable measurements.

Just tested out of curiousity the effect of current-carrying wires outside of the jaws: (Owon CM2100)

Conductor carrying 20A current causes visible 2mA error if closer than apprx 100mm to clamp end. If placed next to jaw opening the error is up to 50mA. Something to keep in mind if working in a crowded electrical cabinet or car wiring harness.

[Kean]

I use model 204A and it works well and is quite accurate. Used for almost 10 years.

This topic is about "clamps meter for low DC currents" and the OP was asking about "mA and uA" measurements.

The UT204A has 40A and 600A ranges.  So the UT204A is not really applicable... unless you know something we don't...

[HKJ]

Just tested out of curiousity the effect of current-carrying wires outside of the jaws: (Owon CM2100)

Conductor carrying 20A current causes visible 2mA error if closer than apprx 100mm to clamp end. If placed next to jaw opening the error is up to 50mA. Something to keep in mind if working in a crowded electrical cabinet or car wiring harness.

That is good, 0.01% error at 10cm is not much. In praxis you would not have 20A next to a clamp measuring mA. Except if you want to measure sensitivity, or you are a bit stupid (Sorry, but that is my opinion).

I have not seen any errors on the CM11, but I only use it to measure low DC currents (That was what I bought it for and it do it very well).

[J-R]

I have not seen any errors on the CM11, but I only use it to measure low DC currents (That was what I bought it for and it do it very well).

Can you check your CM11 to see if it has the same issues as the one in the video?

[mzzj]

Just tested out of curiousity the effect of current-carrying wires outside of the jaws: (Owon CM2100)

Conductor carrying 20A current causes visible 2mA error if closer than apprx 100mm to clamp end. If placed next to jaw opening the error is up to 50mA. Something to keep in mind if working in a crowded electrical cabinet or car wiring harness.

That is good, 0.01% error at 10cm is not much. In praxis you would not have 20A next to a clamp measuring mA. Except if you want to measure sensitivity, or you are a bit stupid (Sorry, but that is my opinion).

You don't always have the luxury of not having current carrying conductors next to clamp measuring mA's, ie previously mentioned car wiring harness.

And some other clamp meters are behaving lot worse:
Fluke 301D gives 0,3A error when jaws are next to conductor carrying 20A current. 6 times worse than the mentioned Owon.
Found out this accidentally in the calibration lab as 301D calibration results were all over the place compared to typical current clamps.

[LeonR]

Just a heads-up: Owon skimped on the protection side of the CM2100/B when compared to the original model (Uni-T UT210E). I posted a video on the CM2100 topic: https://www.eevblog.com/forum/testgear/owon-cm2100b-is-uni-t-ut210e-inspired/

[DaneLaw]

Just a heads-up: Owon skimped on the protection side of the CM2100/B when compared to the original model (Uni-T UT210E). I posted a video on the CM2100 topic: https://www.eevblog.com/forum/testgear/owon-cm2100b-is-uni-t-ut210e-inspired/

No you didnt -  you more like reposted the exact same video that was posted months earlier in 3 posts above yours, even with a direct timestamp to the relevant circuit parts..
and where OP are even talking about the lack of protection after watching that exact video posted months earlier, but all that seemed to go over your head.?

[DaneLaw]

A relatively cheap AC+DC clamp meter I have been puzzling about for the last ½ year is the Winapex 268B
- as it seems to have the current tolerances from Unit-T211B on the clamp with 0.1mA in AC and 1mA in DC while costing around 1/3 of the UnitT- UT211B.

Anybody tried one of these 268B ? - the price seems to be around 35€ [incl. VAT & delivery]






built-in battery (750mAh)  https://ae01.alicdn.com/kf/A1e8c66d9c3e34135b4e6c7ac5177fd0c2.jpg   & https://ae01.alicdn.com/kf/A40b01b1364e84150a4aaf693002f709f9.jpg

[Martin72]

I consider only 2% tolerance in the 60A range to be unbelievable.
As a rule, current clamps of this type are less accurate with increasing current.
In addition, there is this strange "roller coaster" of tolerances in the ACA range.
1.5%, then 2.5%, then back down to 2%.
It's tempting to buy and test them.

[Bobson]

APPA MA3 and MA5 have 1mA +- 1.8%+5D resolution according to specs. Dunno if they are available under Mastech, Benning or other label.

[techneut]

I consider only 2% tolerance in the 60A range to be unbelievable.
As a rule, current clamps of this type are less accurate with increasing current.
In addition, there is this strange "roller coaster" of tolerances in the ACA range.
1.5%, then 2.5%, then back down to 2%.
It's tempting to buy and test them.

I just ordered one from Banggood for €36. Just to see....

[Martin72]

Here are the (photographed) results from the CM11 during the last calibration.

[MathWizard]

I hardly ever use current measurements, (although my meters use currents for resistance measurements too) and in a lot of cases, I'd trust that less than some voltage measurement, but yeah then I'm probably going to use some some measured resistance anyways and Ohm's law....

But yeah how trustworthy are good DMM's or pico-ampmeter's at stuff like measuring input bias currents to op-amps ? I have a good book to read on precision measurement techniques, I need to read more...
https://download.tek.com/document/LowLevelHandbook_7Ed.pdf
https://www.ti.com/lit/ml/slap103/slap103.pdf

[jackobo]

I recently found a current clamp meter that has a dedicated mA range and is still cheap (under 100):

<Peaktech 4350>

I have this one.  It is working quite well even in the DC mA range. Problem is zeroing. Best results are obtained if you zero it in the circuit and don't change the setup after that. But that's not possible if you can not switch off the device under test, which might be the reason to use a clamp meter in the first place.

Need one for possible car battery current leak detection, what do think would 4350 model fit for this purpose?thanks

[ball]

Do any of these default to DC current and continuity?