Two €200 meters: Brymen vs. UNI-T - Page 1
Forum section: electronics / testgear

author: robdejonge
author_rank: Regular Contributor
timestamp: March 28, 2023, 06:08:09 am
content: Candidates:- Brymen 869s + USB kit- UNI-T 171B (includes USB kit)Unique features I'd use:- 2 temp probes on the BM- NCV and data logging on the UTSpecs: they are mostly in the same ballparkPricing: both come out to ~€200 excl VATGut-feel says the Brymen is the more reliable device in the long term.Is that fair?

author: Fungus
author_rank: Super Contributor
timestamp: March 28, 2023, 07:57:42 am
content: Quote from: robdejonge on March 28, 2023, 06:08:09 amYes.NCV is probably useless. I never saw NCV that worked well in real life.An OLED display will eat batteries and has a finite lifespan. It will probably fail in a few years and it doesn't matter if you use it or not.

author: robdejonge
author_rank: Regular Contributor
timestamp: March 28, 2023, 08:17:35 am
content: Quote from: Fungus on March 28, 2023, 07:57:42 amDon't think this has an OLED display. I believe that is the 171C.

author: shapirus
author_rank: Super Contributor
timestamp: March 28, 2023, 08:21:51 am
content: BM can be used for data logging too, it has an optical interface for that. The adapter costs ridiculous money, however. OTOH, there are DIY implementations.This UT is a good meter with favorable reviews, but my gut feeling tells me, maybe wrongly, that UNI-T meters in general don't really belong in that segment. They are (or rather used to be) best bang for buck in the $50-ish range, but of these two I'd probably pick the BM.I actually own a BM869s. It's a good fast meter, however there are some minor annoyances:- slow update rate (1/1s or so) in the AC+DC mode (and in some other modes, where it doesn't really matter)- usable bottom range of capacitance measurement starts at ~100 pF- autoranging in the resistance mode could be faster: I have to fix the range when I need to hand-pick matched resistors from a bunch, for example- no LowZ voltmeter- can't test white (and blue, at least some) LEDs: test voltage is just not high enough- occasionally, pretty rarely, at power-on into the DCV mode, it's stuck displaying 0.0000V until the selector is switched to another mode and back -- and this glitch is a recent developmentOverall, it gives a feeling of a platform that shows its age. It needs a facelift. Nothing critical, however. And its continuity beeper is hands down awesome. And the bar graph is actually useful: while I don't use it otherwise, it can show if the measured voltage has ripple at a frequency beyond what the primary display can reflect.Another feature worth mentioning is its CREST mode: peak detection within, I believe, a 0.8ms window, to capture events that the regular min/max mode won't detect. Can be used to measure short pulses or Vpp of an AC waveform, up to a certain frequency. Can also be used to measure inrush current, with a shunt, without using an oscilloscope.Oh, and it uses the 9V battery, none of that leaky AA/AAA crap. Works perfectly on those rechargeable 2s LiPo packaged in a standard 9V case without an output step-up converter.It also has big ass fuses that cost a fortune and all the requisite input protection circuitry, of course.I don't know if the UT is better or worse in any regard. I wouldn't mind having both, I guess.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 28, 2023, 08:42:02 am
content: I dislike NCV built into a DMM, but that's mainly because I'd find it utterly useless; good luck trying to find the live conductor you want in a 4"x4" trunking full with a couple of hundred cables. Use a decent volt-stick instead.I suppose it has some limited use for finding live cables in a wall, but really I wouldn't trust it. It won't find a cable that's switched off anyway.As for BM869S vs Uni-T 171B, the Brymen is guaranteed to have proper HRC fuses; Uni-T's seem to be a bit random for the same model number in different regional markets. Also, the 869S has been around long enough that most if not all of the quirks of operation are known. Not so sure about the 171B.

author: robdejonge
author_rank: Regular Contributor
timestamp: March 28, 2023, 08:53:05 am
content: Quote from: shapirus on March 28, 2023, 08:21:51 amYeah, I plan on buying this with the meter as it's something I use often. I'll be checking out those DIY options though! :-) I'm hoping there will be Linux software available, from Brymen or elsewhere.Quote from: shapirus on March 28, 2023, 08:21:51 amThat is sort of what my gut feel is too! Is yours as big as mine? ;-)Quote from: shapirus on March 28, 2023, 08:21:51 amSuper useful, this. Thank you for all of that. Any recommendations on a competing model either from Brymen or otherwise? It seems incredible value.Quote from: shapirus on March 28, 2023, 08:21:51 amWas not aware of those. I have a weird dislike for 9V blocks. Might look for one of these!

author: robdejonge
author_rank: Regular Contributor
timestamp: March 28, 2023, 11:25:53 am
content: Quote from: AVGresponding on March 28, 2023, 08:42:02 amNot the first to comment on built-in NCV functionality! I guess I'll keep using my volt stick too

author: shapirus
author_rank: Super Contributor
timestamp: March 28, 2023, 11:34:30 am
content: Quote from: robdejonge on March 28, 2023, 08:53:05 amIf we speak of Brymen, there's not much too look at, besides BM786, which is definitely worth attention. It's a newer model which is in some regards slightly better, in some slightly worse than BM869s. Slightly lower base accuracy, but compare their specs side by side, maybe BM786 will look more preferable for you.I didn't look much into other DMMs of this segment.

author: Fungus
author_rank: Super Contributor
timestamp: March 28, 2023, 12:47:52 pm
content: Quote from: robdejonge on March 28, 2023, 08:17:35 amOh, my bad.(one more thing to hate about Unit-T - they make ranges of meters with the same shape/size/number but wildly different features)

author: sonpul
author_rank: Regular Contributor
timestamp: March 28, 2023, 05:32:29 pm
content: Quote from: robdejonge on March 28, 2023, 08:53:05 amI was puzzled by the choice and was looking for an alternative to the BM869s.I chose the BM789 and I'm glad I didn't buy the 869.Highlighted some of the features I needed.AutoHoldAuto V LoZBeepLitBackLight 30 min.No dual display.Using 3xAAA, I have used Eneloop batteries successfully.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 28, 2023, 05:48:21 pm
content: While the BM786/BM789 are very nice meters, they don't have the data logging feature.

author: sonpul
author_rank: Regular Contributor
timestamp: March 28, 2023, 06:09:38 pm
content: It is very difficult for me to imagine any truly useful task for data logging. I don't understand the dual display in the multimeter either. I bought a second BM789 for any additional measurements without limitation.

author: shapirus
author_rank: Super Contributor
timestamp: March 28, 2023, 06:38:01 pm
content: Quote from: sonpul on March 28, 2023, 06:09:38 pmT1+T2, DC+AC, (less useful) ACV+Frequency.But yeah, second DMM solves this, at the expense of the extra space and wires required and the reduction of the effective input resistance as seen by DUT to 5 MOhm, if you measure volts with both.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 28, 2023, 06:46:15 pm
content: Quote from: robdejonge on March 28, 2023, 06:08:09 amIf you're interested in on-board data logging, the Brymen BM535s might be worth consideration. It appears to have most of the features of the 869s for something like €20 less. But you'd sacrifice specs (10000 count vs 500000 count, 20kHz vs 100kHz bandwidth, and generally less precision/accuracy)Note: I'm just going by a scan of the data sheets - I've never had or used the BM535s, BM869s, or UT171B.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 28, 2023, 06:50:47 pm
content: Quote from: sonpul on March 28, 2023, 06:09:38 pmApparently the OP does, since logging functionality was mentioned more than once including in the "Unique features I'd use" section.

author: Fungus
author_rank: Super Contributor
timestamp: March 28, 2023, 06:52:22 pm
content: Quote from: sonpul on March 28, 2023, 06:09:38 pmDoesn't mean nobody else has a use for it. You might need to leave something running all night and record the voltage (eg. to make a battery discharge graph).

author: shapirus
author_rank: Super Contributor
timestamp: March 28, 2023, 06:57:46 pm
content: Quote from: Fungus on March 28, 2023, 06:52:22 pmAs well as current, temperature, frequency, basically anything that can be measured. There can be a use case for everything.

author: robdejonge
author_rank: Regular Contributor
timestamp: March 29, 2023, 05:31:38 am
content: Quote from: Fungus on March 28, 2023, 06:52:22 pmExactly what I've done before, for logging I used an old smartphone with interval photos. Tedious.

author: robdejonge
author_rank: Regular Contributor
timestamp: March 29, 2023, 05:56:30 am
content: After reading some posts comparing the newer 780 series meters by Brymen, I went and did a bit of a datasheet comparison this morning to see if anything else would jump out. BeepLit, longer backlight and batteries used are differentiating features I like about the 780 series. Data logging one I like about the 870 series, plus (and this is perhaps silly, as it's not for the dual reading) visually I prefer the display on the 870. Overall, as mentioned, spec comparison is a mixed bag in that some is better here, other is better there. Both meet my needs.At this moment, I'm learning towards the 860 series.What I can't judge from spec sheets is how the meters compare in daily driving. Were the little issues listed by @shapirus below addressed in the new series? Is the 780 series overall just a much faster meter?

author: J-R
author_rank: Super Contributor
timestamp: March 30, 2023, 06:03:22 am
content: Absent of a specific feature you need that might be lacking, in general my vote is the BM869s due to the relatively extensive dual display functionality. The various AC/DC/frequency dual display modes and dual temperature are perhaps expected, but I was kind of surprised to see AC current with frequency (secondary), AC+DC current with AC current (secondary), and DC current with AC current (secondary). Of course the BM789 can display those values, just not at the same time.I don't think the BM789 is "faster", and matter of fact, when switching functions on the BM789 it is very slow to switch, a full second or so.Having to remove the case on the BM869s to change the battery is a pain, and the stand is attached to it so you can't just leave it off. The battery cover screws are tiny, as are the ones on the BM789! If you plan to use these 8 hours a day, bench meter for the win...

author: sonpul
author_rank: Regular Contributor
timestamp: March 30, 2023, 07:46:32 am
content: Quote from: J-R on March 30, 2023, 06:03:22 amCan you list at least 2 really useful tasks in which double output is really necessary?The fact that it is necessary for someone, I understand. I would like to hear useful experience.In what task, faster switching could provide more useful information? What can be lost in a second?I am engaged in the development and repair of electronic devices. Tasks are found for the second device. And for a dual display, I can’t think of something. Maybe when repairing frequency converters.I like the BM869s and the dual output capability. Maybe I'll buy it for myself. But I don't see any real benefit.

author: alm
author_rank: Super Contributor
timestamp: March 30, 2023, 08:13:20 am
content: Quote from: sonpul on March 30, 2023, 07:46:32 amVery little is really necessary. Most work could probably be done with a single analog meter with low input impedance, accuracy and resolution. A continuity beeper is also not really necessary: you could look at the display. It's just very convenient and makes some tasks much faster.I find dual display very helpful for looking at DC + ripple (voltage or current) at the same time, and looking at a signal in a system where you aren't sure if it's AC or DC. I had that recently while troubleshooting something powered by an alternator, so it required spinning a wheel to measure. Switching back and forth would have been very inconvenient. Another thing is looking at ACV or ACI and frequency. I was checking an AC signal source and seeing how amplitude and frequency changed under load. Again, switching back and forth while adjusting the load would have been inconvenient.Sure, this could all have been done with two meters, but that's more precious bench space and more leads to hook up to tight spots. Also, it takes more time to scan two displays with your eyes.For these reasons I keep at least one meter with dual display around (though not a Brymen in my case). Other meters can be single display for me.

author: Fungus
author_rank: Super Contributor
timestamp: March 30, 2023, 12:22:33 pm
content: Quote from: alm on March 30, 2023, 08:13:20 amAs much as looking at the tiny second display on a single meter?

author: jonpaul
author_rank: Super Contributor
timestamp: March 30, 2023, 12:25:55 pm
content: Bought a genuine Fluke 87 V for $225.Professional equipment, wil last a lifetime, Class III protection.not ChiCimj

author: 2N3055
author_rank: Super Contributor
timestamp: March 30, 2023, 02:24:21 pm
content: Quote from: jonpaul on March 30, 2023, 12:25:55 pmI bought a Brymen BM869S. World class quality, 5.5 digit, 0.02% class accuracy.CAT IV 1000V protection. For 220€ new with warranty, case and probe..New F87V is cca 550-600€+VAT..Used stuff I don't trust. Not after I saw what people do to them when they didn't buy them with their own money...And yeah, I don't do Sinophobia..Or arrogance. There is always someone smarter than me...What used to be is no more...

author: JeremyC
author_rank: Regular Contributor
timestamp: March 30, 2023, 02:26:20 pm
content: Quote from: jonpaul on March 30, 2023, 12:25:55 pmI do agree.In 1992 I bought Fluke 87, it never let me down and as of today it looks and works the same as 31 years ago. In ~1995 I got used Keithley 135A, the same, this meter works and looks like it was new. If I need higher precision, I use a bench meter.

author: Fungus
author_rank: Super Contributor
timestamp: March 30, 2023, 02:33:25 pm
content: Quote from: JeremyC on March 30, 2023, 02:26:20 pmThere's a huge number of 1980s Radio Shack meters around here that can say the exact same thing.I've got $25 Chinese meters that still work like new after 15 years of frequent use (and counting...)

author: alm
author_rank: Super Contributor
timestamp: March 30, 2023, 02:41:32 pm
content: Quote from: Fungus on March 30, 2023, 12:22:33 pmNo, switching between two meters takes more time for me, especially if they can't be placed close together or you're watching for a change.

author: J-R
author_rank: Super Contributor
timestamp: March 30, 2023, 07:31:05 pm
content: Many DMM features are not used, but your needs might change over time. I just picked up a 199 count Heathkit IM-1212 (with Nixies) and got it all fixed and cleaned up and it's surprising how much you can do with it, haha!Honestly, I don't use my Brymen handhelds much these days, as I have nice bench meters and I do like the 121GW better when hunched over the edge of some equipment due to the nice size & shape. I did use the 15V diode feature a few times recently. Personal taste and experience perhaps.I would like to briefly weigh in on the Chinese topic since it seems to come up a bit. First of all, it's disingenuous to put words into people's mouths and call them racist or phobic when they say they don't like Chinese products or to lump everything into "Asian". There are certain facts about how Chinese manufacturing functions under Communism and it benefits that ideology. That is really the beginning and end of it for me personally.