Usefulness of clamp meter for general electronics work?

[Rooster Cogburn]

I wonder why would you need the clamp at all?

Because wouldn't it be nice if you could measure current as easily as voltage? No switching of DMM leads, no blown fuses if you get the range wrong, no desoldering wires / components, no shunt resistors, no burden voltage, no touching of potentially dangerous parts, no risk of damaging the DUT with your soldering iron, not having to turn everything of to insert your DMM into the circuit, etc.

Obviously you sacrifice a lot of precision, but it seems like a useful tool to have. Certainly at 39EUR.

[Fungus]

Keep up posted as to how often you really use it and what for. 

PS: Be aware that they get magnetized and need degaussing every now and again.

https://www.eevblog.com/forum/testgear/over-current-in-clamp-meter/msg1996529/#msg1996529

[McBryce]

If it's for pure electronics, you'll get much more value from one of these: https://www.amazon.de/Hantek-Signalumformer-Wechselstrom-Gleichstrom-Generator-Mehrfachmessger%C3%A4t/dp/B01M5JBG04/ref=asc_df_B01M5JBG04/

This can be connected to your scope to give you recordable curves of the current being drawn by the circuit and the clamp is a more electronics suitable size. You can also connect it to a multimeter to take simple current readings around the house too.

McBryce.

[Rooster Cogburn]

Keep up posted as to how often you really use it and what for. 

PS: Be aware that they get magnetized and need degaussing every now and again.

https://www.eevblog.com/forum/testgear/over-current-in-clamp-meter/msg1996529/#msg1996529

"
Conclusion

The cheap high sensitive clamp meters will be magnetized and it will show up as an offset on the display, but as long as the zero button is used, it will not affect the measurements.
"

Do I really have to worry about it at all?

And if so, would a few neodymium magnets glued to a case fan's blades make for a good enough degausser?

[BeBuLamar]

I wonder why would you need the clamp at all?

Because wouldn't it be nice if you could measure current as easily as voltage? No switching of DMM leads, no blown fuses if you get the range wrong, no desoldering wires / components, no shunt resistors, no burden voltage, no touching of potentially dangerous parts, no risk of damaging the DUT with your soldering iron, not having to turn everything of to insert your DMM into the circuit, etc.

Obviously you sacrifice a lot of precision, but it seems like a useful tool to have. Certainly at 39EUR.

Of the things the OP listed I don't think he needs to measure current in the range that needed the clamp. Low current the clamp would be not accurate enough.

[Fungus]

The cheap high sensitive clamp meters will be magnetized and it will show up as an offset on the display, but as long as the zero button is used, it will not affect the measurements.

It affects all clamps but the high sensitivity meters will show it more - they're more sensitive.

Do I really have to worry about it at all?

You certainly have to be aware of it and check it regularly.

Even if it's just sat in a drawer it can still get magnetized by the earth's magnetic field. 

And if so, would a few neodymium magnets glued to a case fan's blades make for a good enough degausser?

You could find out and report back 

When the novelty wears off a bit you could try magnetizing it with a neodymium magnet and see how much offset you can get then try the fan trick and report back here.

OTOH I'm betting you can degauss it much more easily just by waving the pole of a strong magnet near it and noting if the offset goes up or down. Reverse the polarity as needed, gradually move further away. You should be able to get it back to zero, no problem. I've fixed old color TVs that way back when TVs had electron guns and wire meshes in the screen.

You can't do any permanent damage to the meter so have a play... 

[HKJ]

I played a bit with magnetizing clamp meters here: https://lygte-info.dk/info/DMMClampDemag%20UK.html

[Rooster Cogburn]

Despite owning and repairing CRTs I don't have a TV degaussing tool, but I'm familiar with the general working concept of it and how to use one. I was thinking worst case I could place the meter on the degaussing coil of the TV to degauss it that way My first thought of improvising a degausser myself was simply to glue a few magnets on the blades of a PC case fan and slow back that away from the clamp. I've seen people improvise CRT degaussing tools this way.

I actually wonder if I can use this meter on a CRT. Every CRT has permanent magnets on the tube and yoke, there's electromagnets all over the yoke and there are several transformers in the power supply section. Wonder if that's too much interference for the clamp to do its job.

I played a bit with magnetizing clamp meters here: https://lygte-info.dk/info/DMMClampDemag%20UK.html

Yeah, I quoted your conclusion in my earlier post!

[robert.rozee]

i have a DerEe DE-3110 clamp meter that includes a 40A DC range. over the years it has been quite useful on enough occasions to easily justify the purchase. one needs to remember that no clamp meter is ever highly accurate, but can provide a useful indication in many situations.

for lower current stuff on the bench, you might like to have a look at these:
https://www.ebay.com/itm/403247125639
(ACS712: Fully Integrated, Hall-Effect-Based Linear Current Sensor IC)

1.2 mΩ insertion resistance. requires a 5v supply @ 10mA, and has an analog output that swings between 0v and Vcc as the measured current goes from -5A to +5A (+/-20A and +/-30A versions also available). minimal external electronics is required to create a working instrument.


cheers,
rob   :-)

[Rooster Cogburn]

I have one of these, it was included in some Arduino sensor pack. You can get them from AliExpress as well.

https://www.aliexpress.com/item/1005001698417485.html

Might be a fun project!

[radiolistener]

Keep up posted as to how often you really use it and what for. 

When you work with mains and mains distribution box, it is irreplaceable and used constantly.

PS: Be aware that they get magnetized and need degaussing every now and again.

Magnetization can be noticed on 2 Amps range if you're measure DC current with high pulses (more than 10-20 Amps). It doesn't matter for AC. If you don't measure 20-50 Amps DC current pulses, you can forgot about magnetization

For example my UT210E was demagnetized 2-3 months ago or even more. I periodically use it for AC measurements and it still remains demagnetized.

[PushUp]

I would recommend the Voltcraft SMA-10, thus you are able to use your handheld DMM, which is probably able to measure mA/µA; especially when you wanna stay under <10A:

https://www.conrad.de/de/p/voltcraft-sma-10-messadapter-schutzkontakt-stecker-buchse-4-mm-schutzkontakt-kupplung-beruehrungssicher-schwarz-123980.html

Here some pix from an early post:

https://www.eevblog.com/forum/testgear/clamp-on-amp-meter-for-checking-house-wiring/msg3533522/#msg3533522

[Rooster Cogburn]

Today I got the 210E Pro delivered from UNI-Ts official store on AliExpress. Seems to work great! mA measurements are quite precise. It's trivially possible to measure to measure the current for an LED or a relay. Or check current drawn from a microcontroller on a breadboard. Just a few mAs of error relative to my Fluke. I did some testing in devices like PCs and AV gear where boards or devices are connected with Molex connectors to a central PSU, seems to work fine. I did some testing in the 20A range by hooking up some power resistors to my bench PSU. There is a bit more drift, but it's still more accurate than the crappy ammeter in my bench PSU.

As a general DMM it's quite crappy with a slow continuity tester, a long wait time till it gets down from the MO range to measure a 100O resistor, no features like min/max, no manual selection of ranges and it's of course just 2000 counts. Of course I bought this device 99% for the <2A DC current measurement feature, so anything else is just a bonus, like having a 2nd multimeter.

Hope it keeps working, I'm quite happy with what I got for <40EUR delivered.

[Jester]

A decent clamp-on is great to have, however I only use the electrician type for 60Hz, typically high current measurements.

I had one of those cheap ac/dc low current Mastech ones it was close to useless for DC.

For electronics a used Tek A6302 or A6312 with amplifier from ebay seems to be the go to solution for precise measurements. They work quite well, and if your patient you can get one for 10-20% of the crazy prices at the top of the spectrum.

I was lucky enough to score two free probes once when I paid about $50 for a empty TEK chassis with just the plugin "toolbox" at an auction , the toolbox contained two good probes!

[Rooster Cogburn]

Small addendum to my impressions:

- I remarked how the meter is not very good as a general purpose DMM, but I want to note how decent the continuity tester is. It stays latched for a while so it's not super responsive when you do the whole quickly hitting your probes against each other thing, but the initial response is super fast.

- The build quality is surprisingly good. It feels heavy, dense and there's nothing creaky about it. Rubberized grips on the sides. Just feels really nice to handle.

- When measuring 1-100mA DC and comparing to my Fluke in mA mode there's a 0-2mA difference. That's in ideal conditions with the little disturbance to the meter after zeroing and the wire going dead center through the clamp, so results will be worse if you bump the meter or can't center the wire or you're measuring something where you can't set the meter down while measuring etc.

Overall this thing is really neat and exceeded my expectations for such a low price.

[beatman]

check the extech 380947.i use in various troubleshoots at low current with good accuracy.

[Electro Fan]

If you're building stuff on the bench then it's fun to put something like this in the circuit: https://www.ebay.com/itm/321455179817

This lets you do a quick/safe check on the current without swapping the leads on the multimeter.

 

[TheBay]

I use mine a fair bit in the workshop when I want to either check something that draws a fair bit of current, usually RF gear. Or if I'm working inside something and want to check the current across some wires without electrically disturbing them.

They are extremely handy when working on vehicles too.

If you get one that's not particularly accurate especially at lower currents, wrap the wire around more than once and do the maths.

[coldelectric]

sorry to just pipe in, but can any technicians here help settle my nerves? I've got a beautiful Pintek Pa-677 current probe (clone of Rigol RP1002c) hooked up to a Rigol DS1054z scope, but I'm agonizing over a no0b question: whether the alternate 50mV/A & 500mV/A scales selected on probe correspond (re: selecting the scale on SCOPE's channel settings) to 0.05x & 0.5x respectively, or to 20x & 2x respectively? Is there a snappy rule of thumb or logical tidbit to help keep it straight? My achy breaky heart thanks yall, and I bow 3 times from the waist in recognition of any luminosity to be conferred.

p.s. The Pintek PA-677 is a great current clamp [for my app: viewing V/I waveforms of impulsed/resonant bifilar pancake coils] because it has no phase offset/lag in my freq. window of interest (ULF RF below 100kHz presently). My YouTube guru has to account for a 10degree phase lag for his current probe at 80kHz with his Pintek PA-655, so that his voltage and current sine waves don't overlap quite so nice (without fiddling). He has to look at a chart that came with his probe and subtract the result visually. After referencing my chart once, I dont gotta f with that.

[Fungus]

sorry to just pipe in, but can any technicians here help settle my nerves? I've got a beautiful Pintek Pa-677 current probe (clone of Rigol RP1002c) hooked up to a Rigol DS1054z scope, but I'm agonizing over a no0b question: whether the alternate 50mV/A & 500mV/A scales selected on probe correspond (re: selecting the scale on SCOPE's channel settings) to 0.05x & 0.5x respectively, or to 20x & 2x respectively? Is there a snappy rule of thumb or logical tidbit to help keep it straight?

The settings on the current probe will be for measuring large currents or small currents, nothing to do with the oscilloscope.

You want the output to be as big as possible so choose 500mV/A whenever possible.

[tautech]

sorry to just pipe in, but can any technicians here help settle my nerves? I've got a beautiful Pintek Pa-677 current probe (clone of Rigol RP1002c) hooked up to a Rigol DS1054z scope, but I'm agonizing over a no0b question: whether the alternate 50mV/A & 500mV/A scales selected on probe correspond (re: selecting the scale on SCOPE's channel settings) to 0.05x & 0.5x respectively, or to 20x & 2x respectively? Is there a snappy rule of thumb or logical tidbit to help keep it straight? My achy breaky heart thanks yall, and I bow 3 times from the waist in recognition of any luminosity to be conferred.

p.s. The Pintek PA-677 is a great current clamp [for my app: viewing V/I waveforms of impulsed/resonant bifilar pancake coils] because it has no phase offset/lag in my freq. window of interest (ULF RF below 100kHz presently). My YouTube guru has to account for a 10degree phase lag for his current probe at 80kHz with his Pintek PA-655, so that his voltage and current sine waves don't overlap quite so nice (without fiddling). He has to look at a chart that came with his probe and subtract the result visually. After referencing my chart once, I dont gotta f with that.

Most probably 20 and 2x are the channel input attenuation you need but it helps to check measurements are correct with a known load. Many current probes have one of their settings equaling 1V/A for a 1x scope input setting.
Once you have it sorted print a little chart and keep it in the box with the probe.

Oh and BTW, welcome.

[5065AGuru]

Not sure what work you do but my HP 428B is VERY useful in my work.
Has a large scale analog meter and seven full scale ranges from 1mA to 10A.
It's DC only but the output BNC jack does allow you to see some AC and noise components.
I don't remember the bandwidth however.

Cheers,

Corby

[coldelectric]

Most probably 20 and 2x are the channel input attenuation you need but it helps to check measurements are correct with a known load. Many current probes have one of their settings equaling 1V/A for a 1x scope input setting.
Once you have it sorted print a little chart and keep it in the box with the probe.

Oh and BTW, welcome.

  yup! ok I figured it out by setting scope to ½ & 2x, and 1/20 & 20x, for 500mV/A & 50mV/a settings respectively, and found that 2x & 20x were what gave consistent amplitudes for Vpp, shoulda tried that sooner but we got it now thanks yall!

[M0HZH]

I've been using the UNI-T UT210E for a couple of years now. It's essential for working on high power DC circuits like power amplifiers (20-50A) and quite convenient to use; otherwise, general purpose multimeters or lab power supplies with good meters are much more useful under 10A.