Brymen BM037 Clamp Meter Teardown 

It still blows my mind that Dave wasnt familiar with the UnitT210E . its literally been the fanfavorit on EEVblog for like a decade and also hacked for 6000 count and its so popular. as a small AC/DC clamp meter for the hobby segment.. goes from 1mA to 100A. and 5 years back they were around 25 to 30 USD, at least when I got mine.. (28USD delivered to Denmark) 210E also got a quite decent NCV, and some extra features, like VFC, and its very small and nimble with a convenient onehand thumb-dial and true RMS. If I was Dave - I would try to get one of these 210E/ or 210E Pro (not for sale as he explains) but simply as a benchmark, to get an idea of the build, and design & performance, of a AC/DC clamp meter at sub 30 bucks., that so many people already have. There is also quite a few alternatives, that has dual display and also 1mA resolution, like the ACM91 and that unit could also be had to around to just under 30 bucks.., but its numerous years back, and the prices are different now..(just checked, not by much ACM91 and ACM92 is still around 30 bucks with incl. 25% EU VAT) There is also the UnitT210EPRO with a black clamp instead of red, that are around 35 to 45 US.. maybe people' will simply purchase that low-entry budget Brymen clamp-meter' from the name alone & perhaps the blue EEV-label, but there is also a chance they simply wont, if its more expensive and it performs worse or equal. If you could get Brymen to fit a Bluetooth chip and get it to work with your Bluetooth app.. that could be the cherry on the top, and be quite handy for a AC/DC clamp meter with such a wireless logging feature.

I really like my UNI-T UT210E. Cheap and works as it should. I'm interested in measuring both AC and DC current 0.1A to maybe 50A + AC/DC voltage 1-300v.

Make them setup the backlight so it stays on for a couple of minutes when you turn it on, they NEVER stay on long enough ! A 600mA range is good if you can get it done, I love my UNI-T UT210e as it is great for portable testing of projects without having to cut into the wires.

Nice one but I would personally prefer one that has the rotary switch at the edge so it could be operated with the thumb in one hand rather than having to use 2 hands like the BM078 or BM079. My range preference would be 6A and 60A, but thats just my personal use scenario.

Hard to beat the UNI-T UT210E, and that's only 35 USD.

All of my sparky mates will enjoy this one Dave!

The UniT 210E is a pretty good and cheap clamp meter. And it gets better after moding the firmware.

These are great. I have a UNI-T and a none contact meter in invaluable when fault finding some automotive systems like alternator faults. For small measurements it might not be that accurate but for them you can use the probes anyway.

I did a fair amount of "research" to find a low-ma reading DC clamp meter and finally bought a fairly cheap one whose specs sounded a lot like some of the more expensive similar meters. As you say, they don't do well below about 50 or 100 ma. I was trying to troubleshoot parasitic leakage currents in a 2006 Chrysler minivan, using this DC clamp technology. One of the big problems is/was that the clamp doesn't seem to know the difference between a wire that is in close proximity to the clamp vs INSIDE the clamp.

Industry would have flyback diodes on relays etc. so a diode test can be useful. A limited resistance range reading is often a limitation of clamp meters in my experience.

I bought a Digi-Sense branded (model 20250-56) clamp meter with 400/40 amp AC/DC ranges. Comes with NIST-traceable calibration for US$100 or so. (In fact it's the only calibrated tool I own. 😅) Cat III 600v, does all the usual multimeter stuff including thermocouple temperature measurement, but no EF. Probes, thermocouple, and pouch included. I only use it occasionally, but it's indispensable for the odd non-contact current readout (like testing my vehicle starters). Looking forward to seeing what you come up with. 👍

Having CAT3, UL Listed, fast acting continuity, a large and clear backlit display (blue would be better as some people are red/green color blind), small formfactor, and diode check, for $100. That's a winner. Diode check is handy for technicians for checking diode bridges and rectifiers, and transistor/mosfet/IGBT output drivers on VFD's and such. Can also use it as a diagnostic for checking panel LED's to see if they're blown. Leave diode check in!

Prova has leakage clamp that can got up to 60A and their new model up to 100. It has a dedicated scale for 40mA I think. We used it a lot. It wasnt AC-DC. Just AC, but True RMS

uniT210E. if you cant get a meter with the res and function of the uniT210E don’t bother selling a clamp meter. Im guessing most of the people purchasing EEVblog meters are electronic’s enthusiast. the uniT210E does read leakage current and on pare with my Magger DET14 and fluke 369. The function and reliability and resolution of the uniT210E is so good is been my edc clamp meter at work for years. I prefer it over all my fluke’s. My everyday dmm’s are Brymen BM869s’s so I love brymen DMM’s but I’ve never seen any of their clamp meters that even come close to having the features for money.

We do diode test on SCR power controllers on heat treat furnaces and also on the large 400 Hz power supplies.

I've got a UnI-t, But I'll order one Dave, to match the blue of my BM235 :) ... and it's a good way for us viewers to 'give back' to you ;)

6 and 60 would seem more useful than 60/600, but given 10mA accuracy 60/600 would still be good. I like the idea of a smaller clamp meter.

you should go for an EEV Blog branded oscilloscope next.

Dave: the 50 nano amp current scale is used for gas valves in HVAC applications

60A and 6A will be best, and the thing you can lose easily is temperature, almost never used. Metal case inserts are easy to add on, almost nothing other than a change in the screw for the case. Hope the diode test voltage is at least battery voltage.

Great video. Thanx.s. What about dismantle the clamp?

yes you test mosfet, igbt and bridges

The Silkscreen looks like the representation of the internal planes of a 4 layer board, I presume they done that for testing/debugging and to see what vias and pads are connected to each other without relying on PC or constantly taking their look from the board to a PC (or printed GERBERS), hi from Roumania.

4:04 I'm sure there are rectifiers asunder in power generation. Wouldn't be surprised if diodes failing short is a regular maintenance issue in wind farms, hydro.

deja vu! :P do it Dave!.. altho .. it should have the uA range...coz...why not?!

Shame about the Sanwa PM300, Dave. I bought one off you then had to go elsewhere to get a second; they were that good.

As a grumpy old man that needs a large screen, I do find it a little painful that the rest of the writing on meters is so small that I have to put my glasses on anyway. First world problems ;)

The 2/20A uni-t model is my go to, bought the 6000 count model and wished I hadn't.

I'm a little confused as to why you say the 16 lines from the main IC to the display aren't enough to directly drive it. Surely you can directly drive up to 64 segments with this setup, and the display on this is what, 4x7 segment with a few annunciators and dp's? Can't be more than 40 or so segments in total, unless there's a bargraph I missed

Range wise I would personally prefer something like 20/200A tbh. My only use for a clamp meter (instead of using a clamp probe for electronic/motor design/diagnostics) would pretty much just be house installations at up to 16 amps (very rarely 32A) and short high current loads like a car battery which shouldn't be more than 200A (though I guess the inrush current could be higher). Given that I would favor the 6/60A range probably, as I don't tend to measure my cars starter an awful lot. But I will gladly admit that I don't have much need for a clamp meter in the first place, so I'm not part the target market. Heck, just getting a current clamp adapter for my DMM would probably make more sense for me. PS. Real shame they won't let you sell other already "taken" products at Brymen, I love my BM869s and I pretty much only got to know their company thanks to you and the eevblog forum. Ironically, the German vendor I bought from also sells your EEVBlog BM786 as well as the 121GW.

I was trying to measure my car start's peak current (I'm starting it from supercaps now) recently, and something with a high range would be nice for that... (Ended up using the grounding wire as a current shunt (and measured on a scope) - it seems like that peak was around 1 kA for a few milliseconds)

Trade the temp feature for a metal threaded insert screw for the back cover? Beef up the plastic for the spring.

The circuit board is right against the plastic behind the spring and supports it, it won't be a problem.

Speaking for myself here, i dont buy EEVBlog rebranded (re modeled?) products for competitive prices, i buy them to support the channel/blog and the knowledge that with these products i can always get whatever weird obscure information i need on the blog. A UT210D with more of a markup would be fine for me, if you could get it in blue all the better ... i like blue. On mine i swapped out the main quad opamp with a chopper amp and it drastically increased stability for only a couple of bucks, possibly you could ask them to drop one of those in to seperate yourself in the market. No matter what you do i will probably grab one anyway, i do use them quite a lot for both low and high current applications but i do tend to bust out the multimeter for under 10A stuff and use my clamp meters for >10A lower voltage DC stuff such as board supplies.

All hail the vacuum-tube-era HP428B DC clip-on milliammeter! 1mA full scale to 10A full scale. Nothing modern and affordable even comes close on sensitivity!

Dave I was looking around Amazon and found your Brymen BM235 for 132.00 I bought one from you a while back did you put it on Amazon or is it a copy

Uni t 204, 600A Clamp, very good and cheap

I tried calibrating extech ma 1500 .I turned pot and it got on the reference voltage but when it gets cold it starts fluctuating all over place and want zero when touch probes

Leakage detectors are not too expensive. There is a generic unit that gets rebranded for about £40 in the UK. It only does AC current though. That's all it does though and the current goes down to 200mA scale with one decimal place.

I would leave out the µA range. I don't like multimeters that have the current inputs on the same jack as the voltage input.

I have the same one from the video and it has a problem, when I place it to measure resistance and without connecting anything, the screen shows 200k, what could it be?

All the time I thought the hook is for convenience. To hang the meter somewhere... 😳

HVAC technicians want micro amps for flame signals on gas furnace repair. Not having that would be a deal breaker for me.

They always make the clamp head too big, the Uni-T UT210 series has a nice compact clamp head.

Would be nice if 6 and 60 V ranges can be added. Or at least 60 V.

Damn!

From where is brymen company manufacturing the meters like clamps and multimeters?

Battery holder is good but it would better if the bottom of the holder didn't have a hole in it, or do AAA don't leak. How easy is it to replace the batteries from it holder?

low current for testing parasitic drainage in cars would be handy :)

Thanks for the video. For me lose the temperature and diode not needed on a clamp meter use a DMM, this may lower the cost. Keep the 60 - 600 amp range. Metal inserts for the screws The Unit-T I have is 2 - 20 - 100amp range, so the low amp range is covered by this meter and the high amp range would be covered by the Brymen you want to have made. Had to do some edits to my comment was typing first instead of thinking first.

👍👍

I would eliminate the slow diode and beep and have 6,60,600 ranges

It's slow & crappy, but for £20 the Uni-T UT21x series are nice & compact and pretty good for value for what it is. The 2, 20 & 100A range one I have covers all my uses. The moulding feels great with nice plastic used and having the wheel hanging off the edge is useful as enables easy one-handed operation. I did have to solder wires from the battery box to the board as the little spring contacts that normally provide continuity started playing up (similar spring contacts to this Brymen one). After a few years of being stored in a damp workshop the power would cut out / flicker on/off when buttons were pushed. --- If you're going for something fully custom then wireless logging to your phone would be a neat feature for a clamp meter.

Seems like a removable battery door with a captured screw would have been a better idea for battery swaps, having to take the case apart with plastic screw threads is a future failure point when the plastic threads and or threaded posts fail, only negative I see and surprised to see Brymen using such a design, seems more like something from UniT or other lower end meters

Appa 18 plus Fantastic clamp meter, fast, quite.precise, a lot of useful features ( pase rotation,.thd, cos fi (it has 2 independent AD so it can measure V and A at the same time, so W of course. AC and DC , and both at the same time too. Check it out I also have the fluke 325 ac/dc but single dac, cannot even be compared to the appa 18+ Check it out

The question is, do you want get REAL result, or you are trying to save money and trying to adjust the readings to your expectations? (Like withe rigol 5000 series :)

CEM clampmeters are decent quality...not sure if they are up to your standards.

Eh. Not my up allay. Looks decent though.

I've had awful experiences with Brymen support

Bloody Hell Dave , can you report on the rail service going on in Australia, you seem to promote the best. Yet trash US

UNI-T UT210E

Опять поставили свой неудобный переключатель.Придумайте что нибудь другое наконец.

I really like my Appa 156B clamp meter, their meters are rebranded by many, many people. Seaward, Megger, Benning, ... For a clamp meter, I would say a significant market for ones that measure DC is the solar industry, and for those of us in that industry 1000V input is a requirement. Almost all of the strings that I'm designing are over 600V. 1100 is the highest I've done though that does require a very cold and very sunny day! I have seen 850-900V on my meters reasonably often though. I would like a more compact clamp in the style of the BM037 that can cope with DC and 1000V. I think the clampy bit on the BM089 looks too big. I've recently picked up a Klein CL800 which I have a feeling might have some Uni-T influence. Seems nice. My clamps are all better at low AC currents than they are at low DC currents. The Uni-T 210E does have a 1mA range but it's a bit pants. I think having that range gives you more confidence in the 10mA range readings though. I think for electronics use in a lab or at home a multimeter is the correct tool, but for anything actually out in the field I'd only use a clamp. I very, very rarely use a multimeter these days but my clamp meter batteries only last six month or so. Partly because I use it a lot, partly because it's not very efficient. Brymen already do blue meters for Metrel.

Give it power meter capability (clamp + leads), and I'll replace my CM210E.

Well, why launch another rebranded multimeter? What is the benefit? Because you can do it and because you enjoy it? Then do it ;-) You asked which (and if) I would buy a clamp multimeter. Well, with all the multimeters, it bothers me that they can't do everything I need in service work. It bothers me that I need an extra device for L/C and ESR measurements. It doesn't matter which manufacturer. In my opinion, there are far too many of them on the market - no one has the overview. My requirements if I would want to buy already: 100mV to 1kV AC/DC, 100µA to around 100A AC/DC (an unfiltered output for the oscilloscope would be helpful, saves the current probe), resistance up to 1Megaohm, capacitance 1pF to 100µF, inductance 1µH to 1mH, ESR/ESL measurement with 100kHz and 10kHz, a very quick continuity tester with switchable beeper. Other people in the room may be annoyed by the beeping so I would use optical alert. A PC interface is helpful for longer observations and getting alertet when something happens. A thermometer function is of little use to me, since I often measure the temperature simultaneously to other quantities. The accuracy does not have to be too high, a calibration with certificate is not necessary. It is about service use, troubleshooting on site with scientific instruments. For adjustment, other measurement technology is needed, which must then also be calibrated. However, these may also be table-top devices siting in the save, warm and dry workshop, each of which masters its few functions very well. BTW: The UNI-T UT210e uses an chopper op amp for the HALL-sensor. Similar devices (for example Voltcraft VC-523) do not. So they do not come down to the unter-10A-range. As long as inductivity of the clamp does not have an effect on the DUT it is OK to wind the wire several times through the clamp. BTW2: At the moment I do a lot of measurements with a 4-ch DSO an diy add-on-devices. Testing ESR, breakdown voltage, ... The graphical representation also helps with explanations for the customer. Maybe I should replace the multimeter with an oscilloscope in the future. And yes, my requirements are somewhat special ;-)

Your own model should use AA batteries instead of those AAA ones.

That’s a TOTAL piece of crap. I bought one because it could read “small current” It CAN NOT READ BELOW 100 mA. I compared with unit with hioki. Any clamp meter is better than this shit Brymen clamp meter. Total waste of money 💰 🤮🤮🤮