Author Topic: Whats $200-400 DMM has the best low ohm measurement  (Read 8904 times)

0 Members and 1 Guest are viewing this topic.

Offline PsiTopic starter

  • Super Contributor
  • ***
  • Posts: 10207
  • Country: nz
Whats $200-400 DMM has the best low ohm measurement
« on: May 06, 2013, 10:31:02 pm »
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 life


Not important
- Capactiance/inductance/frequency measurement
- Data logging


Any suggestions?
« Last Edit: May 06, 2013, 10:58:10 pm by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4316
  • Country: ca
  • Canadian po
Re: Whats $150-300 DMM has the best low ohm measurement
« Reply #1 on: May 06, 2013, 10:40:57 pm »
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.
« Last Edit: May 06, 2013, 10:48:10 pm by Lightages »
 

Offline PsiTopic starter

  • Super Contributor
  • ***
  • Posts: 10207
  • Country: nz
Re: Whats $150-300 DMM has the best low ohm measurement
« Reply #2 on: May 06, 2013, 10:53:07 pm »
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.

« Last Edit: May 06, 2013, 10:54:49 pm by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 38544
  • Country: au
    • EEVblog
Re: Whats $150-300 DMM has the best low ohm measurement
« Reply #3 on: May 06, 2013, 10:58:33 pm »
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.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4316
  • Country: ca
  • Canadian po
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #4 on: May 06, 2013, 11:14:00 pm »
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/
« Last Edit: May 06, 2013, 11:34:31 pm by Lightages »
 

Offline ivan747

  • Super Contributor
  • ***
  • Posts: 2046
  • Country: us
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #5 on: May 06, 2013, 11:25:44 pm »
Does it has to be handheld? If not, that gives you more choices.
 

Offline PsiTopic starter

  • Super Contributor
  • ***
  • Posts: 10207
  • Country: nz
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #6 on: May 06, 2013, 11:54:37 pm »
yeah, has to be handheld.

I will check out the Agilent U1272B, thanks
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline IanB

  • Super Contributor
  • ***
  • Posts: 12310
  • Country: us
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #7 on: May 07, 2013, 12:14:21 am »
Down to 1mR would be ideal, if achievable, but 10mR is acceptable.

Not 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?
« Last Edit: May 07, 2013, 03:04:08 am by IanB »
 

Offline iloveelectronics

  • Frequent Contributor
  • **
  • Posts: 940
  • Country: hk
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #8 on: May 07, 2013, 02:50:59 am »
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.
My email address: franky @ 99centHobbies . com
My eBay store: http://stores.ebay.com/99centhobbies
 

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 3045
  • Country: be
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #9 on: May 07, 2013, 03:23:14 am »
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.

Are 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
« Last Edit: May 07, 2013, 03:25:40 am by Wytnucls »
 

Offline iloveelectronics

  • Frequent Contributor
  • **
  • Posts: 940
  • Country: hk
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #10 on: May 07, 2013, 03:38:24 am »
Are 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

Yes, I am sure. I have this meter :) It 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 :)
My email address: franky @ 99centHobbies . com
My eBay store: http://stores.ebay.com/99centhobbies
 

Offline Zad

  • Super Contributor
  • ***
  • Posts: 1013
  • Country: gb
    • Digital Wizardry, Analogue Alchemy, Software Sorcery
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #11 on: May 07, 2013, 03:38:57 am »
Wouldn't a lower end LCR meter be better at this than a $400DMM?

They seem surprisingly accurate.

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 3045
  • Country: be
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #12 on: May 07, 2013, 03:48:07 am »
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.
« Last Edit: May 07, 2013, 05:22:55 am by Wytnucls »
 

Offline PsiTopic starter

  • Super Contributor
  • ***
  • Posts: 10207
  • Country: nz
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #13 on: May 07, 2013, 05:40:33 am »
Down to 1mR would be ideal, if achievable, but 10mR is acceptable.

Not 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?

yeah, resolution.

The main reason i need it is to track down PCB shorts.
« Last Edit: May 07, 2013, 05:42:23 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline eevblogfan

  • Frequent Contributor
  • **
  • Posts: 569
  • Country: 00
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #14 on: May 07, 2013, 06:41:44 am »
hey

I 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 LM317  :-//

Cheers :)
 

Online kripton2035

  • Super Contributor
  • ***
  • Posts: 2678
  • Country: fr
    • kripton2035 schematics repository
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #15 on: May 07, 2013, 07:04:00 am »
some low-ohm free schematics here :
http://kripton2035.free.fr/continuity-repos.html
hope this helps.
 

Offline quarks

  • Frequent Contributor
  • **
  • Posts: 874
  • Country: de
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #16 on: May 07, 2013, 11:57:19 am »
hey

I 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 LM317  :-//

Cheers :)

That is probably what you mean
https://www.eevblog.com/forum/projects/milliohm-resistance-adapter/
 

Offline grumpydoc

  • Super Contributor
  • ***
  • Posts: 2906
  • Country: gb
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #17 on: May 07, 2013, 12:09:26 pm »
Quote
The main reason i need it is to track down PCB shorts.

Wouldn't a current limited supply and a rather more run-of-the-mill DMM be better suited?
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 38544
  • Country: au
    • EEVblog
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #18 on: May 07, 2013, 12:27:15 pm »
Quote
The main reason i need it is to track down PCB shorts.
Wouldn't a current limited supply and a rather more run-of-the-mill DMM be better suited?

1mohm resolution is very handy for tracking down shorts. Often better than dicking around with a PSU.
 

Offline eevblogfan

  • Frequent Contributor
  • **
  • Posts: 569
  • Country: 00
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #19 on: May 07, 2013, 12:29:42 pm »
hey

yup that's the thread :P
 

Offline PsiTopic starter

  • Super Contributor
  • ***
  • Posts: 10207
  • Country: nz
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #20 on: May 07, 2013, 01:48:25 pm »
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 one :)
I also need (ok.. want) it for checking shorts in other projects.
« Last Edit: May 07, 2013, 01:56:17 pm by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 3045
  • Country: be
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #21 on: May 07, 2013, 03:40:24 pm »
Perhaps this is what you need:

 

Offline eevblogfan

  • Frequent Contributor
  • **
  • Posts: 569
  • Country: 00
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #22 on: May 07, 2013, 03:54:09 pm »
hey

that's tremendous over kill for the task , really

If 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 )   :bullshit:  >:D
 

Offline StubbornGreek

  • Frequent Contributor
  • **
  • Posts: 290
  • Country: us
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #23 on: May 07, 2013, 05:28:01 pm »
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.
"The reward of a thing well done is to have it done"
-Ralph Waldo Emerson
 

Offline robrenz

  • Super Contributor
  • ***
  • Posts: 3035
  • Country: us
  • Real Machinist, Wannabe EE
Re: Whats $200-400 DMM has the best low ohm measurement
« Reply #24 on: May 07, 2013, 07:54:39 pm »
+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


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf