Seeking input/opinions/warnings prior to purchase - 0.001 Ohm resolution - Page 1
Forum section: electronics / testgear

author: Kubota Konnoisseur
author_rank: Newbie
timestamp: October 11, 2017, 05:07:28 am
content: Hello EEVBlog folks,I've been researching recently and viewing Dave's (and others') videos regarding hand-held multi-meters. I was quite horrified by, but sheepishly enjoyed Dave's post #868 where he and friends absolutely terrorized a Keysight U1282A, which brings me to the purpose for this post.I'm about to retire my beloved Fluke78 that still works like a champ after 25 years of faithful service. Along with the excellent service of that meter, I've always received excellent customer support from the people at Fluke. So I'm a huge fan and particularly partial to the Fluke brand, but I'm considering alternatives strictly because I'd like to have one feature that none of the hand-held Flukes currently offer (to my knowledge) - 0.001 Ohm resolution. The Fluke289 will do 0.01 Ohm, but that is the top of their offerings.All of that said, I'm leaning toward the Keysight U1282A, mainly because I've been able to see and read a lot about it, and especially because with the zeal of a Spartan it refused to succumb quietly to Dave and friends' nefarious nihilism.Another one I'm interested in is the REED Instruments R5005, mainly because it does offer the high resolution at about half the price in US$, but with fewer bells and whistles (no phone app). What concerns me is that I've been unable to find a single review, teardown etc. of the REED R5005. From what I've read here, I'm under the impression that the REED is made by a Chinese manufacturer that makes meters marketed by many companies. I'm ok with that so long as it is high quality.My specific need for the high resolution resistance measuring capability is to test the auxiliary windings that are clumped in with the main windings on the generator ends that Kubota uses on their small (6kW - 10kW) generator packages. The detection winding spec is 0.03 Ohms, so I'd like to have the extra digit just to be precise. Aside from that specific need, I do work on electronic fuel injection engines and industrial gensets of all sizes and high voltage as well, so quality, safety and durability are a must.Plus I need a new toy and a good tax write off.I guess my question is: Should I stick with the Fluke289 with 2 digits resolution and phone app at the highest price, go with the Keysight at just less $ to have the extra digit and the phone app, compromise with the REED for the least $ but no phone app, or is there another bargain priced meter of high quality (sorry Extech, that excludes you) that will suffice? Excellent customer support and service/warranty are also factors to be considered.Lastly, the 3 meters I've mentioned are the most readily available to me which is why I've narrowed down to them at this point.Thank you for reading this rambling if you're still doing so, and by all means if there are other meters I should consider, please do elaborate.

author: evava
author_rank: Regular Contributor
timestamp: October 11, 2017, 10:58:17 am
content: Fluke 289 has/can 0.001ohm resolution on LoOhm range, but.......that range unfortunately settles very long, about 1minute, which is ANNOING!I do not recommend to use it often.Anyway, I recommend you to use meter with four wire measurement capability for 0.001Ohm resolution.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 11, 2017, 12:28:13 pm
content: If you want reliable 1 milliOhm resolution, you should consider a 4 wire kelvin system.Everything else will bring too many errors in to your measurements.I would use a separate Milli-Ohm-Meter for this task and not a DMM.

author: Kubota Konnoisseur
author_rank: Newbie
timestamp: October 12, 2017, 02:11:00 am
content: Thank you evava and HighVoltage for your replies.I'm basically a former car mechanic who hates the car business, the car repair business and working on cars, except for toys and hot rods. So after 20 years of misery, I switched 10 years ago to working on industrial engines/equipment (lotsa diesel engines and generators) and love it. So I have never used that type of instrument or anything but a hand held DMM.I had considered just that option, but when I began looking at 4 wire milliohm meters on Amazon and reading spec sheets, there are about a milliohm, oops, million choices and then I was seeing megaohm meters and meggers - I got overwhelmed.I understand that a milliohm meter checks for low resistance with high resolution, and a megaohm meter checks for high resistance, and I think I understand (maybe? or not!) that meggers apply power to the windings in order to check continuity, resistance etc. while powered, but past that I'm clueless. Is that correct? Is that considered under load or just powered? Are there meggers that do all of those functions?To use any of those devices, would I need to plug into a wall outlet? I often go on service calls (to the side of a rail road for instance) where I have no shore power, just my tiny inverter plugged into the cigarette lighter of my service truck to keep my laptop and cellular hotspot device powered. That's why I was concentrating on hand held DMM.In most instances, I'm able to determine with certainty whether it's just a faulty AVR or an obvious open, short or short to ground (melted!), with just my trusty ol' 78 and eyeballs, but I just encountered a unit that had all of the above, yet not melted, plus 2 blown fuses and literally a rat's nest inside the cabinet - Cool awesome maintenance!Do enlighten me, if you please, with weblinks for me to read or a basic explanation if you don't mind terribly. Either way, thank you both again for your input so far.

author: Dubbie
author_rank: Unknown
timestamp: October 12, 2017, 02:56:32 am
content: The reason there aren't really meters with that resolution is that it is pretty meaningless without a 4wire connection.and 4wire is kinda overkill for a handheld meter.Why not look at a benchtop meter with 4wire support? There are plenty to choose from.

author: Yogomonoyakub
author_rank: Newbie
timestamp: October 12, 2017, 04:37:28 am
content: What is the key content of the course?