Low Current (mA) DC Clamp Meter - Page 1
Forum section: electronics / testgear

author: testian
author_rank: Regular Contributor
timestamp: March 19, 2019, 08:41:24 pm
content: I am currently looking into buying a clamp meter for quickly measuring 4-20mA signals in the process industry. But it should also be capable of measuring AC and DC Voltage.It seems quite difficult to get a suitable meter.Currently i found these meters:Benning CM11https://www.benning.de/products-en/testing-measuring-and-safety-equipment/current-clamp-multimeter/benning-cm-11.html?sbd=TUR?sbd=TUR?sbd=TURFluke 771https://www.fluke.com/en-gb/product/calibration-tools/ma-loop-calibrators/fluke-771expensiveonly current measurementsKYORITSU KEW 2500https://www.kew-ltd.co.jp/en/products/detail/00039/only current measurementsUNI-T UT 211B or UT 210Echeapnot so accurateDoes sb know of other devices or has some experience with the one above related to measuring mA?(for reference an old thread:https://www.eevblog.com/forum/testgear/low-current-dc-clamp-meter/)

author: Kean
author_rank: Unknown
timestamp: March 19, 2019, 10:30:13 pm
content: I've had a Fluke 771 for quite a few (~10) years, and if you can afford it I'd highly recommend it. Very handy and great reading resolution and accuracy for a low current clamp meter with 10uA resolution and 0.2% accuracy. It is difficult to make a decent low current clamp meter, and you want to look after it and keep it from large magnetic fields. All of which is why you don't find the higher accuracy on more general purpose models.I also have a few UT 210E's clamp meters, but their DCA ranges are not good enough for process control with only 1mA resolution and 2% accuracy. UT211B is a similar, not sure if it does 0.1mA in DCA.The Benning CM11 looks like a good compromise, with 100uA resolution and 1% accuracy. So the Fluke is an order of magnitude better - depends if you need that.For further process control calibration & testing I've got a Mastek 7221 (oldest, ~8 years), a Mr Signal MR9270S (newest, ~1 year), and a few others. These are all handy but they're not clamp meters so require you to break the connection. Mr Signal particularly has extensive features, but that makes it a bit complex to use.I don't do much process control stuff right now, but if I was buying again I'd maybe get a Fluke 773, and a Brymen 869S for everything else, with a plug-in current clamp for higher currents.

author: orion242
author_rank: Unknown
timestamp: March 20, 2019, 02:01:55 am
content: I know guys with the Fluke model and they are happy with it. Deal with 4-20ma all the time. Least for me, I'm not willing to shell out the cost for the limited use. In most cases I can override an I/O so the process is maintained while I slip my 289 in the circuit to double check. Normally its new equipment startup and voltage checks alone eliminate most common issues. Wiring mistakes or total failure are the biggest things I run into on startup. Many other toys I would rather have than the fluke clamp on, though it would be nice. How many meters can one pack in a tool bag though?Also wonder how accurate these clamp-ons are. If your sensor range is large, a small error might have you chasing your tail. Non-issue with a 289 inline ma measurement.

author: testian
author_rank: Regular Contributor
timestamp: April 03, 2019, 06:38:02 pm
content: Thx for your recommendation.https://www.eevblog.com/forum/testgear/benning-cm11/

author: orion242
author_rank: Unknown
timestamp: April 04, 2019, 02:04:40 am
content: Looks nice.At the price and only CAT IV 300 V, its not something I can use for control signals and then measure 480vac+ high fault current circuits I'm controlling...The use is too limited for the cost IMO.