Affordable high resolution clamp meter exist? - Page 1
Forum section: electronics / testgear

author: Rifter
author_rank: Contributor
timestamp: August 06, 2014, 01:33:39 am
content: Hello all, im not sure if this is possible but if it is im sure you guys know about itLooking for a DC clamp meter to measure current and would like 1ma resolution all the way down to 10ma.Is this possible for under $100?I know a lot of meters claim 1ma resolution but are not accurate sub 100ma. I would like down to 10ma accurate.Thanks.

author: Monkeh
author_rank: Super Contributor
timestamp: August 06, 2014, 01:42:27 am
content: The CEM DT-337 may suit you:http://www.ebay.com/itm/CEM-DT-337-Clamp-Meter-AC-DC-1mA-High-Resolution-Low-Current-V-R-C-Hz-Functions-/201047070957

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: August 06, 2014, 01:46:39 am
content: Quote from: Monkeh on August 06, 2014, 01:42:27 amThanks for linking to my storeThis meter will be back in stock within the next couple of days.

author: Rifter
author_rank: Contributor
timestamp: August 06, 2014, 01:50:35 am
content: Quote from: iloveelectronics on August 06, 2014, 01:46:39 amI was actually looking at that exact meter as I just purchased a brymen 257 from your store on Monday and saw it there.Can anyone comment on its ability to be accurate at sub 100ma DC currents?

author: Monkeh
author_rank: Super Contributor
timestamp: August 06, 2014, 01:53:20 am
content: Quote from: Rifter on August 06, 2014, 01:50:35 amMJLorton's video review shows pretty respectable repeatability at low currents. DC clamps are finicky, though, just moving your fingers around can upset them.

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: August 06, 2014, 02:06:57 am
content: To be honest a clamp meter wouldn't really be very useful if you need accuracy down to small current at 10mA level. The reading would jump around just by moving it slightly.

author: Rifter
author_rank: Contributor
timestamp: August 06, 2014, 02:22:58 am
content: Quote from: iloveelectronics on August 06, 2014, 02:06:57 amYeah the thing is I want it for two purposes, one any clamp meter will work for(automotive), the other is for measuring laser diode currents, the issue with the laser diodes is they are to sensitive to voltage/current spikes and require solid soldered connections to the driver not alligator clips, so when I measure current I either have to solder on the test leads from my DMM between driver and diode, or alligator clip on a small resistor across the diode and measure it and do the math to get current. Obviously if I can get a clamp meter that's will accurately measure low currents that would greatly speed up testing currents on my laser diodes

author: omgfire
author_rank: Regular Contributor
timestamp: August 06, 2014, 05:28:12 am
content: Quote from: Rifter on August 06, 2014, 02:22:58 amThis does not make much sense. Your bm257 has 1.7mV/mA burden voltage on mA scale.You can use 0.1Ohm or less resistor since your bm257 has 10uV resolution.Speaking of clamps, Uni-t releasedUT211Bnot so long ago.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 06, 2014, 06:18:26 am
content: By definition, no. Cheap, fast, accurate, pick any two.Comes to mind, there are current sensors that use a servo nulling sense method, and saturation detection or something like that for the mechanism; so they have little or no hysteresis (it's effectively under AC bias), and accurate gain and offset (secondary sense, tertiary feedback / null windings). But as far as I know, they're pricey.Tim

author: Rifter
author_rank: Contributor
timestamp: August 06, 2014, 06:19:17 am
content: Quote from: omgfire on August 06, 2014, 05:28:12 amDon't have the BM257 yet its in transit

author: omgfire
author_rank: Regular Contributor
timestamp: August 06, 2014, 06:28:07 am
content: Quote from: Rifter on August 06, 2014, 06:19:17 amBurden voltage is not unique to Brymen multimeters.

author: Rifter
author_rank: Contributor
timestamp: August 07, 2014, 04:34:43 am
content: Quote from: omgfire on August 06, 2014, 05:28:12 amCan you comment on the accuracy of the 211b in its 600ma low current mode?It looks like exactly what I want on paper but have heard uni t quality can be all over the map even within different sub models in the same line so I'm unsure of the 211b's quality.

author: Ebivetar
author_rank: Contributor
timestamp: August 07, 2014, 12:15:25 pm
content: Quote from: iloveelectronics on August 06, 2014, 02:06:57 amActually, you are wrong.We have KYORITSU and FLUKE process clamp meters at work. They are great.I guess you get what you paid for...Also,kyoritsu 2500is around 100 usd cheaper thenfluke 771. If you are ready to spend 500+ then go with one of this.You should consider thekew mate 2012R. This is multimeter that can measure 120 amps with 10mA resolution.p.s Here are some links of kew 2012R:http://www.kew-ltd.co.jp/en/products/multimeters/2012R.htmlhttp://www.globaltestsupply.com/c/393/Kyoritsu_Kew_Mate_2012R_Multimeter.htmlIt is not under $100, but this is most affordable if you are looking for accurate readings.

author: Wytnucls
author_rank: Super Contributor
timestamp: August 07, 2014, 12:48:05 pm
content: The Fluke 77X series are very expensive and are limited to a maximum of 100mA, as they are dedicated process clamp meters.http://en-us.fluke.com/products/ma-loop-calibrators/fluke-773-process-calibration-tool.html#overviewThe Kyoritsu 2012R doesn't have low amp ranges. A resolution of 10mA on the 60A range, with a quoted 2%+8 digits, gives a modest guaranteed accuracy of 100mA DC.

author: Ebivetar
author_rank: Contributor
timestamp: August 07, 2014, 01:15:11 pm
content: Quote from: Wytnucls on August 07, 2014, 12:48:05 pmYes, Fluke meters are expensive. I was assuming OP is interested in process clamps because he was looking for DC milliamp clamp meter.In my country you can get the kyoritsu 2012R for little less then 200 USD. I have used this meter and this is why i just suggested this.If the OP is on tight budget, I guess CEM clamp meter is good choice too. Never used CEM meters before, except the ones that are sold under the EXTECH brand ( good price/quality ratio)

author: Electro Fan
author_rank: Super Contributor
timestamp: August 07, 2014, 07:27:35 pm
content: http://www.ueitest.com/sites/default/files/product-resources/CA30MA%20DATA%20SHEET.pdflooks like maybe another choice.Claims pretty good accuracy and 1ma resolution to 30 amps. Not sure if it will go all the way down to 1ma, but maybe.Seems to sell for about $150? If it covered 1ma to 30am and had good accuracy it might be a winner.On a different but related item, the CEM meter looks pretty good but seemed to fall down a bit on accuracy - any chance that inside the meter is a simple pot that could be used to tune the meter against a reference device? (I have found in very in expensive Radio Shack DMMs that you can sometimes access a pot that allows for pretty decent accuracy once it's tuned against a reference device.)PS, found some more UEI products:http://www.testequipmentdepot.com/uei/pdfs/dl389.pdf- anyone have any experience with UEI?

author: Ebivetar
author_rank: Contributor
timestamp: August 08, 2014, 12:21:10 pm
content: Take a look at this models also.http://www.uni-trend.com.cn/en/product/2014_0717_652.htmlhttp://www.uni-trend.com.cn/en/product/2014_0718_675.htmlI am assuming that this should be cheap.

author: LukeFinch
author_rank: Newbie
timestamp: August 12, 2014, 06:36:58 am
content: I'm just reading a comment that the clamp meter doesn't work so good and it result is suspicious. Actually I was Looking for such meter and I just made my mind to buy but some comments made me confuse. so please some one make clear what's wrong with it, I believe you people because I already buy anInsulation testerswith your recommendation and it's going well.