Low current (mA) clamp meter with recording for automotive use (dark current) - Page 1
Forum section: electronics / testgear

author: hugh_CZ
author_rank: Newbie
timestamp: October 08, 2024, 08:16:53 am
content: I am looking for current clamp meter to be used in automotive dark current measurement.Minimum currents to be measured are around 20mA, max can be up to 10A-15A peaks... I understand that clamp meter wont be very accurate, but having the values of +-5mA would be enough for me.And clamps because I want to handover this one to the workers, that are not trained in some electrical measurement, etc...Measurement recording is a must, so I can evaluate the results later. Ideally some industrial solution maybe? Budget is not a problem, but lets try to stay in reasonable price (+-1000€).Is there any tool that may cover the above mentioned please? Thanks for any tips!

author: Byacey
author_rank: Newbie
timestamp: October 18, 2024, 03:59:49 pm
content: Any clamp meter for DC current will be using a hall effect sensor, which typically is too sensitive to be using for automotive use because of all the stray magnetic fields under the hood of the engine compartment.I have one, but it's really only suitable for currents from a few amps up to 1000A.Measuring down into the mA range, I wouln't put much faith in the accuracy of the readings.

author: David Hess
author_rank: Super Contributor
timestamp: October 18, 2024, 11:41:08 pm
content: I have been thinking of getting aBK Precision Model 316which is suppose to have a resolution down to 1 milliamp for that application.

author: Kean
author_rank: Unknown
timestamp: October 19, 2024, 04:54:06 am
content: Quote from: David Hess on October 18, 2024, 11:41:08 pmThat looks good, and seems a very similar design to the ST-337, but the ST-337 (aka TENMA IN05268) has a 4A range which suits my typical use much better.I posted a quick comparison of some of my clamp meters earlier this year with measurement data from sub-1mA to 100mA DC.https://www.eevblog.com/forum/testgear/good-clamp-meter-for-low-dc-currents/msg5252202/#msg5252202I have since bought a couple of Owon CM2100 clamp meters this year, and they seem to be reasonable. The smaller opening on the ST-337 and F771 are better in my opinion, but may limit multi-turn use.The Fluke 771 is still my go-to for small currents (less than 100mA, ideally less than 20mA for high accuracy) when it is not feasible/necessary to break to loop. It is less sensitive to external factors and reorientation than any others, but the 100mA limit makes it unusable a lot of the time.

author: David Hess
author_rank: Super Contributor
timestamp: October 19, 2024, 09:18:05 am
content: Quote from: Kean on October 19, 2024, 04:54:06 amThe big difference between them is the number of counts. Would have to test them to learn drift and noise levels.BK 31610A by 0.001A2.5%+10$175Owon CM21002A by 0.001A2%+8$40Bluetooth Version AvailableExtech 3809504A by 0.001A2.5%+4$160UNI-T UT210A2A by 0.001A2%+825$UNI-T UT210B2A by 0.001A4%+3025$

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 19, 2024, 08:02:29 pm
content: The only question that remains is what the BK 316 is an overpriced rebranding of? 😉

author: DaneLaw
author_rank: Frequent Contributor
timestamp: October 19, 2024, 09:20:52 pm
content: I only have two AC+DC stand-alone clamp meters.One for low and one for high, none of them have log-ablelity..I would reckon your best bet at-least on the cheap, is likely the Owon CM2100-BT, as Owon tends to have logging ability in their app... though don't have that clamp meter, only one of their older DMM with BT (blåtand) series 35..210E it ain't bad for low current, but you need to cycle that zero-button to the cows come home, if you want down to the last mAAre the Extech MA61 & MA63 Unit-T 210E & 211B rebadges?They extremely similar, just with added freq.HT208D (1000A) is useless for low current.. you need above +200mA.. personally got it for the high current, primarily its inrush that are quite fast and down to single digit ms and holds its own compared to way more expensive brand-names, not least for a clamp meter that costs between 30 to 35$. (HT208D)210E with 0-10mA cycling & a cheap spotwelder looped with HT208D on Inrush current.

author: Martin72
author_rank: Super Contributor
timestamp: October 19, 2024, 09:28:36 pm
content: Quote from: KungFuJosh on October 19, 2024, 08:02:29 pmA really good current clamp can hardly be overpriced.For example, the CM11 from Benning, which is out of the question for the OP because it has no logging function.(Pics: Excerpts from the last calibration protocol)

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 19, 2024, 09:39:35 pm
content: Quote from: Martin72 on October 19, 2024, 09:28:36 pmIt can if it's the BK badge that makes it cost more than the original they copied/rebranded. 😉

author: Martin72
author_rank: Super Contributor
timestamp: October 19, 2024, 09:44:16 pm
content: How could I disagree with the expert?But you're right, there is a twin to the BK316.It doesn't cost 175...https://gtc.ca/product/cm100-milliamp-clamp-meter/

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 19, 2024, 10:20:35 pm
content: The TecPel DCM-043 doesn't cost as much as either. 😉

author: Kean
author_rank: Unknown
timestamp: October 19, 2024, 10:35:58 pm
content: On AliExpress you will find another rebadge with the search term "CENTER-223". Possibly the OEM version, but hard to know.Several other apparent rebadges can be easily found via image search, like the HellermannTyton T223:https://www.hellermanntyton.co.za/products/digital-clamp-meters/t223/911-00038

author: David Hess
author_rank: Super Contributor
timestamp: October 19, 2024, 10:37:09 pm
content: Quote from: Martin72 on October 19, 2024, 09:44:16 pmThat is even more expensive!A couple months ago I did a survey of 1 milliamp resolution DC current clamps, and the BK was the one I have been thinking of getting.

author: Kean
author_rank: Unknown
timestamp: October 19, 2024, 10:49:58 pm
content: Quote from: David Hess on October 19, 2024, 10:37:09 pmYeah, he was making a joke about the higher price. You can surely find rebrands that are cheaper than BK (see above), but maybe not through a trusted source. These are not huge investments, so a little extra markup is OK. I'd likely take the risk on an CENTER-223 if I actually needed yet another clamp meter.You are in the USA, so you should have little problem with getting support from BK so paying a slightly inflated price is reasonable. The margins are not huge so you shouldn't expect much support beyond standard warranty terms. They are in Yorba Linda, California if I recall correctly. Many years ago I had a great local BK reseller I dealt with who would hand deliver my new equipment.

author: Martin72
author_rank: Super Contributor
timestamp: October 19, 2024, 11:04:47 pm
content: We all have a “natural mistrust” of products that are available under many brand names but are priced differently.And the most expensive one is the bad one, because it wants more than is actually worth it.It can be right from case to case, but I wouldn't rely on it.

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 19, 2024, 11:21:43 pm
content: The TecPel is available in the US on Amazon.For me it's not a question of mistrust, but instead knowing that BK likes to rebrand stuff and charge extra for their sticker. If they offer a longer warranty or something, cool. Otherwise, what's the point?

author: Kean
author_rank: Unknown
timestamp: October 19, 2024, 11:50:51 pm
content: As usual we have wandered off track.As suggested by DaneLaw, I also think that the OWON CM2100B is a good starting point for evaluation, as long as Bluetooth logging is workable.It has a wide clamp opening (17mm) for heavy cables, and 2A, 20A, and 100A ranges.Of course you only get the 1mA resolution in the 2A range, and you need to be pretty careful about zeroing in the same magnetic field orientation just before you clamp the cable.I don't have the Bluetooth version, so I am not sure how easy it is to use, but at a price of about USD $60 it certainly is not a big deal for a business to justify purchase for a trial.If logging via something like SD card is needed, then the EEVblog 121GW DMM plus a plug in clamp probe would be the way to go.It might be hard to find a combination which works as well for low currents.e.g. the ESI 695 has 20A and 80A ranges, with 100mV/A and 10mA/A output, and zeroing is via a knob rather than button press.Also, SD card removal on the 121GW isn't as easy as one might hope.

author: jfiresto
author_rank: Frequent Contributor
timestamp: October 20, 2024, 09:10:49 am
content: Quote from: KungFuJosh on October 19, 2024, 09:39:35 pmThe extra cost for a BK goes toward the warranty – or I hope it still does. I had the temperature range go out on a 390A DMM after a couple years. Although BK didn't sell the model in Europe, they were prepared to ship a new, tested replacement to their sister firm in France, and have them send it on.

author: David Hess
author_rank: Super Contributor
timestamp: October 20, 2024, 01:04:51 pm
content: Quote from: KungFuJosh on October 19, 2024, 11:21:43 pmAre they the OEM? Their price is not much lower than BK. They are remarking and selling other things like differential probes though.I see that TecPel provides asimilar AC/DC clamp for use with an external multimeter. Apparently they are based in Taiwan instead of China which is nice. I keep wishing Appa multimeters were more available in the US.Update:The CA-60 clamp probe and DCM-043/BK316 are obviously made by the same company, but I was not able to find the OEM.QuoteI actually did not know BK was rebranding to that extend. I expect some rebranding because instruments are more specialized, like current clamps.Quote from: Kean on October 19, 2024, 11:50:51 pmFor low current measurements, I prefer a narrow clamp opening because pickup from external magnetic fields is lower.

author: Kean
author_rank: Unknown
timestamp: October 20, 2024, 03:50:40 pm
content: Quote from: David Hess on October 20, 2024, 01:04:51 pmI somehow doubt TecPel is the OEM, but I cannot be sure.As you mention, looking at their product range they are selling other brands (Siglent, GW Instek) and I see rebadged Tonghui products.Their cheaper products have no design consistency, so I do think they are just sourcing from various OEMs, maybe doing some final assembly.There is also an older thread on here discussing the possibility of TecPel being an OEM, but come to a similar conclusion to me that they are likely just a distributor/re-badger.https://www.eevblog.com/forum/chat/what-does-fluke-uni-t-gwinstek-mastech-and-others-have-in-common-tecpel/BK Precision are also known to rebadge Tonghui, and other brands like some low end Siglent scopes (e.g. BK 2190E is Siglent SDS1102CNL+).Maybe TecPel cannot afford the fees to rebadge Siglent or GW Instek, so they just sell them as-is to have a wider range of products.Quote from: David Hess on October 20, 2024, 01:04:51 pmYeah, I mentioned my preference for smaller clamp openings earlier in the thread. In this case I was responding to OP's desire for an automotive clamp meter with low mA to 10+A measurement ability.