Whats $200-400 DMM has the best low ohm measurement - Page 1
Forum section: electronics / testgear

author: Psi
author_rank: Super Contributor
timestamp: May 06, 2013, 10:31:02 pm
content: I'm looking to buy a new DMM in the $200-400 price range and one thing i need is a good relative low ohms range.Down to 1mR would be ideal, if achievable, but 10mR is acceptable.What options are there other than the Fluke 87 and Fluke 287 ?Other important specs are- True rms- Fast proper continuity range- 10-20A current range- Acceptable battery lifeNot important- Capactiance/inductance/frequency measurement- Data loggingAny suggestions?

author: Lightages
author_rank: Unknown
timestamp: May 06, 2013, 10:40:57 pm
content: What exactly do you mean by low ohms? What do you want to read down to?Almost every handheld multimeter is useless below 1 ohm when it comes to absolute accuracy specs, and most below 10 ohms. To get accurate readings lower than that you need a good LCR meter or a high accuracy benchtop meter. Your price range won't get you a good benchtop or LCR meter so I am not sure what you want.The one handheld mulltimeter I suspected would maybe be good on lower ohms range is the Fluke 289, but at $600.

author: Psi
author_rank: Super Contributor
timestamp: May 06, 2013, 10:53:07 pm
content: Sorry, i edited the ohm specs in after posting.Absolute accuracy isn't important, relative accuracy is fine.The 10mR on the Fluke 87 and 287 is fine, i was just wondering what other options are out there in other DMM brands.

author: EEVblog
author_rank: Unknown
timestamp: May 06, 2013, 10:58:33 pm
content: 1mohm resolution is possible on the Agilent U1272A and the like. As do many LCR meters.But that's resolution, not accuracy. If you are serious about proper accurate low ohm measurement you need a 4 wire measurement system. You can get that on most old bench meters, e.g. HP 3478A, and maybe some new ones.

author: Lightages
author_rank: Unknown
timestamp: May 06, 2013, 11:14:00 pm
content: UEi DM397 has 0.001ohm resolution. But I just did a video on it and I really can't recommend it from my personal experience. jwrelectro has one and his worked fine so it is up to you.https://www.eevblog.com/forum/testgear/uei-dm397-i-think-not-an-update-on-this-multimeter/$235 plus shipping.My Brymen does 0.01 ohms resolution and is around $240 plus shipping. A REALLY good multimeter for the price.And now that you changed your price requirements after my first reply...... Yes of course Dave is right, the Agilent U1272B is worthy at almost $400. If you do buy one of these, read this thread and open yours to see if it has the same problem.https://www.eevblog.com/forum/testgear/agilent-u1272a-crappy-soldering/

author: ivan747
author_rank: Super Contributor
timestamp: May 06, 2013, 11:25:44 pm
content: Does it has to be handheld? If not, that gives you more choices.

author: Psi
author_rank: Super Contributor
timestamp: May 06, 2013, 11:54:37 pm
content: yeah, has to be handheld.I will check out the Agilent U1272B, thanks

author: IanB
author_rank: Super Contributor
timestamp: May 07, 2013, 12:14:21 am
content: Quote from: Psi on May 06, 2013, 10:31:02 pmNot sure if you mean resolution or minimum value?If you could read a resistance as 0.534 ohms that would be 1 milliohm resolution. Is that what you mean?

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: May 07, 2013, 02:50:59 am
content: The Uni-T UT60H is a 40,000-count DMM that has 0.001 ohm resolution. It may not be the $200+ higher end meter you're looking for though, and depending on your location the only source for this meter may be eBay or the likes of DX or Aliexpress.

author: Wytnucls
author_rank: Super Contributor
timestamp: May 07, 2013, 03:23:14 am
content: Quote from: iloveelectronics on May 07, 2013, 02:50:59 amAre you sure Franki?The manual says 0.01 Ohm on the lowest scale of 400 Ohms, just like the 71D.http://www.uni-trend.com/manual2/UT60H%20%20Eng%20Manual.pdf

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: May 07, 2013, 03:38:24 am
content: Quote from: Wytnucls on May 07, 2013, 03:23:14 amYes, I am sure. I have this meterIt was the first meter I bought when I picked up this hobby again last year. I actually bought it from the same shop (WECL) where you bought some of your gear

author: Zad
author_rank: Super Contributor
timestamp: May 07, 2013, 03:38:57 am
content: Wouldn't a lower end LCR meter be better at this than a $400DMM?They seem surprisingly accurate.

author: Wytnucls
author_rank: Super Contributor
timestamp: May 07, 2013, 03:48:07 am
content: The OP wants a portable DMM with a resolution of 1 mOhm, so a meter with a low range and a high count is required.(A 50,000 count meter needs a low range of 50 Ohm for a resolution of 1mOhm)Accuracy needs 4-wire Kelvin measurements and there are dedicated meters (LCR and others) for that function.

author: Psi
author_rank: Super Contributor
timestamp: May 07, 2013, 05:40:33 am
content: Quote from: IanB on May 07, 2013, 12:14:21 amyeah, resolution.The main reason i need it is to track down PCB shorts.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: May 07, 2013, 06:41:44 am
content: heyI think that hunting after some DMM who offer you that is not the best option , you can build your own mOhm adaptor quiet easily , I cant find the thread ( I've searched ) but robrenz made one out of simple LM317 and battery ,all you need is simply 1A source and you are good to go , it can be within 1% and you'll be just fine , for 33mOhm short , you'll see 33mV across the short , I think it's no brainer , don't go for the HIgh end expensive solution while you can do this with the cheapest DMM and some LM317Cheers

author: kripton2035
author_rank: Super Contributor
timestamp: May 07, 2013, 07:04:00 am
content: some low-ohm free schematics here :http://kripton2035.free.fr/continuity-repos.htmlhope this helps.

author: quarks
author_rank: Frequent Contributor
timestamp: May 07, 2013, 11:57:19 am
content: Quote from: eevblogfan on May 07, 2013, 06:41:44 amThat is probably what you meanhttps://www.eevblog.com/forum/projects/milliohm-resistance-adapter/

author: grumpydoc
author_rank: Super Contributor
timestamp: May 07, 2013, 12:09:26 pm
content: QuoteWouldn't a current limited supply and a rather more run-of-the-mill DMM be better suited?

author: EEVblog
author_rank: Unknown
timestamp: May 07, 2013, 12:27:15 pm
content: Quote from: grumpydoc on May 07, 2013, 12:09:26 pm1mohm resolution is very handy for tracking down shorts. Often better than dicking around with a PSU.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: May 07, 2013, 12:29:42 pm
content: heyyup that's the thread

author: Psi
author_rank: Super Contributor
timestamp: May 07, 2013, 01:48:25 pm
content: The reason for the current interest in getting a low ohm meter is to do with fusing.Currently a product im working on uses a slowblow fuse for short circuit protection but i want to move to a polyfuse as its more forgiving of user mistakes.In order to do that i need to limit the driver mosfets current/temperature, under short circuit conditions, to something it can handle until the polyfuse actives.Being able to measure the resistance of PCB tracks would be quite handy for this.I could get the info i need without a new low-ohm meter but its a good excuse to buy oneI also need (ok.. want) it for checking shorts in other projects.

author: Wytnucls
author_rank: Super Contributor
timestamp: May 07, 2013, 03:40:24 pm
content: Perhaps this is what you need:

author: eevblogfan
author_rank: Frequent Contributor
timestamp: May 07, 2013, 03:54:09 pm
content: heythat's tremendous over kill for the task , reallyIf it was me , I would simply either use my CC or my E3610A or whatever , and pass 1.00A throo kelvin setup ( 4 wires )you have no reason to be more accurate then 1% , feel free to use even 5% resistors for the task ,BTW - my cc does better then 0.05% so that's over kill with my HP3478A ( 10uV resolution )

author: StubbornGreek
author_rank: Frequent Contributor
timestamp: May 07, 2013, 05:28:01 pm
content: A nice solution (only if you're willing to look at a slightly different device) would be the bk 879b LCR meter. Excellent resolution and good accuracy. (stating the obvious) This doesn't work if you needed a full functional DMM also. And, the meter is overkill but adds functionality to your test equipment assortment that may be useful in the future.

author: robrenz
author_rank: Super Contributor
timestamp: May 07, 2013, 07:54:39 pm
content: +1 for the LCR meter for low ohms. But only if it is true 4 wire kelvin all the way to the clips or tweezers.Example here