Not another Multimeter advice thread. - Page 1
Forum section: electronics / testgear

author: hydrocarbonPrimate
author_rank: Newbie
timestamp: September 11, 2022, 07:44:39 pm
content: Hi guys,I currently have a CEM DT-9985 Which has served me well considering how poor the build quality is. It is playing up and and I need something newer that can handle voltage measurement from VFDs and Generators (actually alternators) with noisey outputs.I am sort of between worlds, in that I do a bit with electronics, a lot with automotive and a little with three phase and domestic stuff.I have often looked at buying and LCR meter, for measuring inductors (but I think I read that is more art than science and they are not too accurate?)I use capacitance measurements all the time and need to be able to measure a good range of values.I also need good resolution on Voltage and Resistance because fault finding on automotive stuff, it can be very handy.I also occasionally use the insulation test which is handy,I need a meter that is fairly rugged and has a back light these are very important. I use diode test quite often but never seem to test transistors without them being in a board.The spreadsheet does not seem properly formatted on open office so I'm struggling to read it so was looking for any advice that might be helpful.Many Thanks guys

author: joeqsmith
author_rank: Super Contributor
timestamp: September 11, 2022, 07:58:38 pm
content: I used a CEM for several years for work. The plastic was in very poor shape when I finally retired it.What does "playing up" mean? If you could explain the symptom you are seeing, maybe someone could help you fix yours.

author: hydrocarbonPrimate
author_rank: Newbie
timestamp: September 11, 2022, 08:15:36 pm
content: Well it says its IP67 waterproof, but it has no seals on the main selector switch and spilt a very small amount of petrol on it, after that the meter screen would go blank, i took it apart and cleaned up both boards and selector switch contacts and re-assembled, it works now but is very slow transitioning OL to a reading, It's hard to explain, but I no longer trust it.The last capacitor measurements it came up OL when trying to measure a 200uf start cap and the last voltage measurement on 240v the screen went blank after some time.

author: AVGresponding
author_rank: Super Contributor
timestamp: September 11, 2022, 08:36:35 pm
content: Not sure on the best thing to clean petroleum distillate/gasoline contamination. Only thing I'd say is, if you can still smell it, even faintly, it's still contaminated.IP67 relates to water, petrol is much less viscous, and so can creep through small gaps more easily, though the lack of seals on the main switch is puzzling; how did it get the rating? I'd expect water to be easily able to penetrate, given IP67 specifies proof against immersion of 1 metre, and strong water jets from all directions.

author: nightfire
author_rank: Frequent Contributor
timestamp: September 11, 2022, 09:00:40 pm
content: Disassembly and washing with IPA (iospropylic alcohol) would be my favorite treatment- needs to be continued as often as there is no smell of traces of petrol left.In car petrol some additives and other stuff is present and might also form some kind of oily coat on sensitive electronics, creating some small leakage currents.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 11, 2022, 10:09:15 pm
content: You haven't mentioned a budget so it is a little difficult to narrow down a recommendation but, I would suggest a Brymen, take your pick from their comprehensive range or, a surprise candidate, the Amazon, yes, that Amazon, their 90DM610, 6000 count, IP67, CAT IV at 600V, substantial build quality and under typically under £40, the price varies according to Amazon's whim. I bought one out of curiosity and am pleasantly surprised at how good it is and the build quality. If you have a more substantial budget, have a look at Flir, or go for a pre-loved Fluke, plenty on feepay at much, much less than the new price. I picked up an as new, actually unused, 87 V for £150 a few years back!

author: hydrocarbonPrimate
author_rank: Newbie
timestamp: September 11, 2022, 10:12:15 pm
content: Quote from: AVGresponding on September 11, 2022, 08:36:35 pmFrom my amature observations of it, I would summise it as dustproof / splashproof at best, its about as waterproof as a paperbag.Anyway i cleaned the contacts with ipa or acetone, i cleaned any residue i could see from parts of the board but no smell or visible residue remained.Anyway I still need a meter with low pass that can RMS me some voltage measurements from non inverter generators and VFDs, anyone using any they are happy with?

author: hydrocarbonPrimate
author_rank: Newbie
timestamp: September 11, 2022, 10:14:41 pm
content: Thanks unknownparticle, I'll check out some of those suggestions.Budget is flexible looking to spend £100-500.

author: Fungus
author_rank: Super Contributor
timestamp: September 11, 2022, 10:43:08 pm
content: Quote from: hydrocarbonPrimate on September 11, 2022, 07:44:39 pmIf you need insulation test then the choice is quite narrow.We're big fans of Brymen around here. Brymen make a couple of candidates:https://brymen.eu/shop/bm878/https://brymen.eu/shop/bm887/

author: joeqsmith
author_rank: Super Contributor
timestamp: September 11, 2022, 10:58:25 pm
content: Did you also clean the two Zebra connectors for the LCD?40,000 count with an insulation tester may be hard to come by. I'm not a fan of Keysight but maybe this is an option:https://www.keysight.com/us/en/assets/7018-04371/data-sheets/5991-4290.pdf

author: bdunham7
author_rank: Super Contributor
timestamp: September 11, 2022, 11:28:16 pm
content: I'd suggest not trying to combine too many functions into one box, as there are limitations on how far this can go without compromises. Having a DMM with CAT-IV 600V ratings, full 1000V meter protection and full LCR capability for example--that is just not doable AFAIK. If you want the insulation tester function, get a separate unit. The VICI V60B+ and its ilk are $50 or so, I'm sure Aneng and so forth have their own competitors in the 'good enough' space. Since you are in the UK and you can buy Brymen with a warranty, look at one of those for your DMM function--I think the 869S has the VFD HF rolloff feature you are looking for. I'm guessing you aren't looking at springing for a Fluke 289. Then if you want an LCR meter, get one--the DER DE-5000 is highly regarded by some here and can be had for less than $100.With regards to CEM, if you are going to buy junk at least stick to buyingcheapjunk. That way when it blows up it's easier to just chuck it, provided it doesn't kill you. I'm willing to bet you can get all 3 of the instruments I mentioned for not much more than an "IP-67 rated" CEM all-in-one (well, two-in-one anyway) unit--and they won't be junk. At least the Brymen and DER surely won't. And for more info on CEM and IP-67, read this discussion and both links in the message.https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg3714598/#msg3714598

author: hydrocarbonPrimate
author_rank: Newbie
timestamp: September 11, 2022, 11:56:24 pm
content: Thanks all, I'm thinking i can bin the insulation test off and pick up a standalone tester for that.I'm looking at the sanwa pc7000 japanese made. Will compare it to the brymen and other suggestions you've all made.Thanks you all.

author: nightfire
author_rank: Frequent Contributor
timestamp: September 12, 2022, 07:28:00 am
content: Regarding LCR testers: In UK the Peak Atlas series of devices is easily obtainable, and they have a good reputation also.Also, Hioki Multimeters seem to be fairly affordable (just checked with the farnell online shop) and are also regarded as viable alternative to the other big brands.

author: J-R
author_rank: Super Contributor
timestamp: September 12, 2022, 08:14:36 am
content: Some of Sanwa's DMMs are basically Brymens. The PC-7000 for example uses Brymen's DMM chip, and the feature set is somewhere in between the BM867s and BM869s.It has the same AC bandwidth limits of the BM867s but does have the VFD/LPF feature of the BM869s.Accessories such as the magnet and USB/PC adapter are identical to Brymen's.However, the construction is a bit different, so it's not simply a rebrand like Greenlee, etc.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 12, 2022, 11:38:30 am
content: Another brand to consider is Hioki, designed and made in Japan. Not cheap but very good. Also, I don't know why but I forgot to mention that I have a virtually unused Brymen 869S for sale, complete with box and all originally supplied accessories, PM me if that is of interest. Out of interest, this is Joe Smiths favourite DMM, or one of his favourites.

author: adam4521
author_rank: Regular Contributor
timestamp: September 12, 2022, 08:31:07 pm
content: QuoteI did the same, although my £150 87V was clearly ‘used’, it was 100% and remains what I rely on several years later. There is a steady supply of them used. It has robust look and feel and has the inverter drive roll off feature you are specifically after. Or get the Brymen via Telonic.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 13, 2022, 06:36:37 pm
content: Yeah, much folding stuff can be saved this way! All my Flukes have been acquired off Feepay at considerably less than retail, I always go for as new ones, they aren't as frequently available in that condition, but patience is rewarded sooner or later! I got a 289 in a special kit, with lots of accessories for £250, as new, boxed!!! I was the only bidder! I know many don't like the 289, I find that surprising, I find it a superb meter, maybe a bit on the large side but thats no big deal.

author: Bobson
author_rank: Regular Contributor
timestamp: September 13, 2022, 08:13:06 pm
content: Quote from: unknownparticle on September 11, 2022, 10:09:15 pmAmazon DMM 90DM610 is made by CEM. It's what the topic starter wants to avoid.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 14, 2022, 11:57:28 am
content: Didn't know that, thanks. I am surprised though because my impression is very good, it feels and works considerably better than other low price meters, build in particular feels quite substantial. Haven't put the IP67 claim to the test but I doubt Amazon would state that if it wasn't credible. Maybe we need a tear down, Joe Smith style!

author: wasedadoc
author_rank: Super Contributor
timestamp: September 14, 2022, 12:55:43 pm
content: Quote from: unknownparticle on September 14, 2022, 11:57:28 amThe very similar model without temperature measurement is explored inhttps://www.youtube.com/watch?v=wfFG8v-RPQ8.Maybe not a Joe Smith style review but could be a lot worse.

author: evava
author_rank: Regular Contributor
timestamp: September 14, 2022, 12:56:48 pm
content: I think APPA 607 tick all your boxesGive it a chance!No need to look any further!

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 14, 2022, 10:02:17 pm
content: Quote from: wasedadoc on September 14, 2022, 12:55:43 pmYeah, I've seen that, just watched it again to remind myself of his findings. He seemed to approve and the guy knows his stuff. For the price this and the 610 can be had on UK Amazon, it's a really good buy IMHO.

author: wasedadoc
author_rank: Super Contributor
timestamp: September 17, 2022, 11:26:54 am
content: Quote from: unknownparticle on September 14, 2022, 10:02:17 pmUK Amazon price has jumped from under £38 to more than £60.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 17, 2022, 12:15:49 pm
content: Yeah, it does that! Odd's are it will reduce again, but there is no pattern to the fluctuation. It went as low as about £34, I bought two at that price, so I can have one handy in the garage and in my carry bag for field use. The original one I bought at around £40 I use on the bench.For anyone wanting one, just wait until black Friday, it's sure to be reduced then.