Multimeter with continuity test buzzer that responds immediately ? - Page 1
Forum section: electronics / testgear

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 01, 2020, 01:20:19 pm
content: As per title - I'm often tracing tracks and source/destination points on old boards with no schematics and need a decent multimeter which will respond immediately to detected continuity - so if I have one probe on one point and am very quickly moving the other probe from pin to pin I'd like a continuity buzz from even a very brief and momentary contact when continuity is detected, I don't want to have to hold the probe in place for half a second or more.Any recommendations please on a decent (and relatively cheap) multimeter which will do this?Thanks(I'm in the UK so need a model that can be purchased here).

author: bdunham7
author_rank: Super Contributor
timestamp: August 01, 2020, 01:28:10 pm
content: Handheld or bench? What is relatively cheap to you? I'll be happy to tell you the continuity response times of whatever meters I have, but they may not be 'cheap'.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 01, 2020, 02:21:13 pm
content: The UT90A is fairly fast

author: tooki
author_rank: Super Contributor
timestamp: August 01, 2020, 02:57:51 pm
content: Quote from: SolderSucker on August 01, 2020, 01:20:19 pmFluke meters are famous for their awesome continuity testers.But don’t underestimate the opposite: buy a meter so cheap that it has a simple unlatched continuity test. It will react instantly, but you have to pay close attention because the beep itself will be very brief if you’re just running it down a line.Also, don’t underestimate the role of the probes. Fluke’s continuity test is astonishingly good at overcoming poor probes, but on other meters, good probes are critical. It makes a bigger difference than you would ever imagine. The very best in this regard, of all I’ve tried, are Probe Master probes, whose sharp points and gold plating dramatically improve the continuity testing on most meters.The only other meter I’ve ever used that is as good as (or better) than a Fluke is my Keithley 2015 bench meter. If you’re looking for bench use, a used Keithley 2000 series is a great choice. Otherwise, get a Fluke handheld.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 01, 2020, 03:02:35 pm
content: Thanks very much for all of the advice and recommendations.I should have said that it's a handheld meter that I'm after.I have some decent fine tipped probes (so fine that they bend a bit too easily if I'm not careful).What is relatively cheap to me? Preferably under 50 UK Pounds.I'd heard that Fluke meters were good for what I'm after but they're also a tad too expensive for my wallet.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 01, 2020, 03:04:12 pm
content: I haven't looked at many Fluke branded meters. The 17B+ was one of the slowest I looked at.Data I have collected for the continuity tests can be found here:https://docs.google.com/spreadsheets/d/1cXzYpIoyVm9QJUju4KXqM22CEQZP3_xwWvDyeVwxTy4/edit#gid=570637604

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 01, 2020, 03:22:42 pm
content: How about the cheapest Fluke on the block, the Fluke 101 ? Is that particularly fast?My prime uses are:a) Continuity checkb) Resistance measurementc) DC voltage measurement

author: BravoV
author_rank: Super Contributor
timestamp: August 01, 2020, 04:44:31 pm
content: Quote from: SolderSucker on August 01, 2020, 03:22:42 pmFluke 101 is considered slow, but I love it as it has no current measurement, and cheap. Also survived the HV test by our Lord of DMMs HV Zapper aka joeqsmith.I did comparison of my 101 vs my work horse 189, you clearly hear & see the different, suggesting to crank up the sound volume so you can hear the probe's metal pins making contacts and followed by the sound. Both tests were using the same probe.Fluke 189, fyi it uses chirping sound instead of beeping. Some people hate it, but personally I love it, as its quite annoying, and easily recognized and stands out among back ground noise when doing continuity test.Fluke 101 .. no contest here.Hope this helps.

author: bdunham7
author_rank: Super Contributor
timestamp: August 01, 2020, 04:45:41 pm
content: I don't have a cheap meter suggestion for you, but I did try a few of mine. Are you 'continuity scanning' where you run the probe down the pins of a fine-pitch SMD package looking for a beep? Or are you just hand-probing one at a time and find some meters very slow?All of my bench meters that have continuity were pretty sluggish and I can see how a quick fingered person might become impatient.The only unit I tested with a very quick responseand latching(so you get at least a short beep instead of a click or chirp) was my old Fluke Scopemeter with a reliable 1.75mS pulsewidth response. My BK Precision handheld was less than 10mS, but was a faint click or chirp that got stronger up to 20mS or so where it was easily audible even with some background noise. It works fine in normal use, so I would guess that 20mS is fast enough for one-at-a-time poking, but for the pin-scan method, you want all the speed possible. To give you an example of what the numbers mean, with the Scopemeter I could not strike the terminals fast enough to NOT get a beep, no matter how hard I tried, even flicking them past one another so they just tapped as they flew by.I hope that helps a little. FWIW, I find that the biggest obstacle to continuity checking is getting a reliable connection, not speed. This is especially true on 'old' boards where I typically poke and prod and wiggle 3 or 4X and still occasionally miss a point.

author: HKJ
author_rank: Super Contributor
timestamp: August 01, 2020, 05:00:01 pm
content: In my reviews I measure the continuity speed and post a millisecond value. There are some cheap meters that are fast, but I cannot remember which ones.https://lygte-info.dk/info/DMMReviews.htmlI measure the speed by shorting the input with a MOSFET controlled from a function generator, I find the fasted puls width where it reliable detect a short. Some meters have some background processing that stops continuity tests once in a while, the speed I post mostly includes time for this stop (I usually test 10 to 20 shorts in a row with about 1 second between them).

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 01, 2020, 05:27:09 pm
content: Thanks again for the additional info and advice, @BravoV - those videos were very helpful thanks. Yes, that chirping IS annoying on the 189, but at least it's fast response compared to the 101.@bdunham7 said - "Are you 'continuity scanning' where you run the probe down the pins of a fine-pitch SMD package looking for a beep? Or are you just hand-probing one at a time and find some meters very slow?"I do both depending on the circumstances.@HKJ - thanks for the pointer to the reviews.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 01, 2020, 06:04:26 pm
content: The cheapest meters that I reviewed and have decent continuity and overall features and accuracy are the Uni-T UT123, the UT136C and the Richmeters RM113D. Of these, the UT123 is the only one that has no current measurement and the 113D is the fastest overall (not only continuity). All them are around $15 FOB.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 01, 2020, 06:16:49 pm
content: https://www.eevblog.com/forum/chat/fun-for-nerds/msg3116404/#msg3116404

author: joeqsmith
author_rank: Super Contributor
timestamp: August 01, 2020, 07:14:56 pm
content: "When you use a crap tool, it just wants to make you stop and cry and do something else ..." Proceeds to knock the Fluke 87V.I thought it was a pretty good video. In his requirements, he doesn't mention latching or speed. He does list detection resistance of 5 ohms. Not sure I like that 20mA number.Quote from: HKJ on August 01, 2020, 05:00:01 pmI also use a FET jig that allows me to compare up to three meters when I look at the settling times. I consider the frequency less important than the minimum pulse they can detect. They are normally fast enough with long holds but I will typically drag like the OP and want something that can detect short pulse times. Open and short resistance, I just use a substitution box. The open circuit voltage and short circuit current, I check with the bench meter.

author: Wytnucls
author_rank: Super Contributor
timestamp: August 01, 2020, 08:04:20 pm
content: The continuity test of the UT139C is reported to be fast and latched. (30 quid)https://www.ebay.co.uk/itm/UNI-T-UT139C-True-RMS-Digital-Multimeter-Ammeter-Auto-Manual-Range-Data-Hold/283882486223?hash=item4218b6f9cf:g:aekAAOSwE~xa-9kk

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 09:18:09 am
content: Quote from: SolderSucker on August 01, 2020, 01:20:19 pmYou don't say what meter you're currently using so we have no baseline.Joe measured quite a few meters response times, they're in the speadsheet in this thread:https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/Look for the "continuity test" tab in the sheet.One of the fastest "cheap" meters there is the Kasuntest KT6000, also known as the Aneng 860B+ - one of my favorite meters. You can get one here:https://www.aliexpress.com/item/33004834123.htmlQuote from: SolderSucker on August 01, 2020, 03:22:42 pmNo.

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 09:23:39 am
content: Quote from: tooki on August 01, 2020, 02:57:51 pmThe Fluke 8060A had a response time of 10uS, it's all been downhill since then.Quote from: tooki on August 01, 2020, 02:57:51 pmBrand/price guarantees nothing. Fluke makes some slow ones, so does Brymen.

author: indman
author_rank: Super Contributor
timestamp: August 02, 2020, 10:53:36 am
content: Quote from: RoGeorge on August 01, 2020, 06:16:49 pm"Do one thing and do it well".You can do well not only one thing, but several at once!And equally good!https://www.youtube.com/watch?time_continue=93&v=DzDw6zD81iE&feature=emb_logo

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2020, 10:59:34 am
content: Fluke 8060A, Fluke 8024B, Fluke 87, 87V, Brymen BM22sAll have decent implementations of continuity. As for the rest, it’s a shit show.Edit: 8060A and 8024b are by far the best I’ve used.

author: ledtester
author_rank: Super Contributor
timestamp: August 02, 2020, 11:12:02 am
content: You might try this DIY design:https://youtu.be/N2M-p-OGvPg

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 12:27:50 pm
content: Quote from: bd139 on August 02, 2020, 10:59:34 amA lot of the Brymens have fast continuity and they're far cheaper then Flukes.Brymen is one of the few manufacturers who puts the response speed in the specifications, eg. my Brymen BM857s is < 100uS.See the last page of this PDF:https://brymen.eu/wp-content/uploads/biall/102020/102020.KARTA_EN..2015-07-08.1.pdf

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2020, 12:40:40 pm
content: But they’ve got that bloody awful feature which remembers which sub mode you’re in. Just what you need: a guessing game based on several annunciators to work out which mode you were last in every time you change the main controlGoing to be honest but the 87/87V rotary selector implementation is the best. Better than the earlier flukes which had a similar guessing game.

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 01:38:28 pm
content: Quote from: bd139 on August 02, 2020, 12:40:40 pmI find it very convenient. Certainly better than switching back to AC mode every time I breathe on the selector switch.

author: joseph nicholas
author_rank: Frequent Contributor
timestamp: August 02, 2020, 02:11:07 pm
content: Yes, the memory thingy is a gotcha. It's the kind of thing computer programmers code into your computer that makes you guess what the correct answer is then it tells you you guessed wrong. I fuckin hate that.

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 03:41:06 pm
content: Quote from: joseph nicholas on August 02, 2020, 02:11:07 pmIt's not as if it's random FFS.If the 'solution' is to spend three times as much money, get a far less capable meter,withthe annoying AC mode thing, then call me unconvinced.

author: bd139
author_rank: Super Contributor
timestamp: August 02, 2020, 04:53:30 pm
content: AC mode first is a safety feature to prevent:1. Turn meter on volts.2. Poke in socket. Hmm reads zero. Must be off.3.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 02, 2020, 06:16:19 pm
content: Quote from: bd139 on August 02, 2020, 10:59:34 amYou need to go out more. The examples I mentioned, as well as Wytnucls and Fungus, are very decent for this spec alone for 10~20 times less money.Quote from: bd139 on August 02, 2020, 12:40:40 pmI agree with you there 100%. Both the 87V and the 179 IMO are the best rotary switches I know.Quote from: Fungus on August 02, 2020, 01:38:28 pmI agree with you regarding convenience, but the default AC mode on the 87V is only on the current ranges. It has segregated V~ and V= positions in the switch. I personally don't understand the fuss about default AC mode, but I rarely use current measurements anyways.Quote from: bd139 on August 02, 2020, 04:53:30 pmAs I mentioed above, this is not applicable to the voltage ranges on the 87V, so no s*** show.On the systems I work, I cannot afford to rely on mechanical memory and defaults to measure things - disasters are costly. I better damn well pay close attention to the meter's screen and which range it is on before blindly believing the measurement. In that context, recalling the last mode used is very convenient for me.

author: Fungus
author_rank: Super Contributor
timestamp: August 02, 2020, 07:01:22 pm
content: Quote from: bd139 on August 02, 2020, 04:53:30 pmIt only does it in amps mode, so if you're poking it into a mains socket then you've got bigger problems.PS: If you often find yourself selecting DC volts mode on your Fluke then maybe a dual-display Brymen is in order.

author: J-R
author_rank: Super Contributor
timestamp: August 03, 2020, 07:42:12 am
content: The U1461A has Auto AC/DC V, mV and uA/mA mode switch positions. With the dual display enabled, you get the AC/DC auto detection on the primary display and AC+DC on the secondary.

author: Fungus
author_rank: Super Contributor
timestamp: August 03, 2020, 10:20:28 am
content: Still, there's some awful slow meters out there. Joe mentions an Amprobe that takes 150ms to respond.Maybe the OP (now vanished) has one of those in which case almostanythingwould be an improvement.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 03, 2020, 10:41:48 am
content: Quote from: Fungus on August 03, 2020, 10:20:28 amThe OP is in fact still reading the very helpful replies with great interest and responding where required.

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 11:18:13 am
content: Quote from: Fungus on August 02, 2020, 09:23:39 amWell, I haven’t used a 101 or 17, so if they’re slow, I have to believe those saying it. But generally speaking, Fluke is famous for great continuity testers. At the bare minimum, I can confirm it’s true for the 87, 87V, 175, and 179.I’m also not sure if the lab tests all accurately capture just how well the Fluke continuity works in practice. In the end, it seems to never beep when it shouldn’t, but also never fails to beep when it should, even when conditions aren’t ideal (like with corroded terminals or cheap probes with awful plating*). In contrast, for example, the Aneng AN8008 has a continuity tester that works awesomely with Probe Master probes, but is only “ok” with cheap probes.*Fluke’s own probes aren’t actually thaaaat great in this regard. That they work great for continuity testing with Fluke meters is a testament to the meters’ circuitry and programming, not the probes themselves. A good way to compare probes is to use continuity on a meter with absolutely unlatched continuity tester and short the probes together: Probe Master will produce a silky smooth, perfect uninterrupted beep even with a light touch, while inferior probes will be scratchy unless pressed together tightly. (How tightly depends on the plating.)

author: joeqsmith
author_rank: Super Contributor
timestamp: August 03, 2020, 11:34:54 am
content: Quote from: tooki on August 03, 2020, 11:18:13 amIf the 87V represents the best there is to offer (which is an opinion not shared with guy who made that video showing their home made setup) , I still have that fairly new one that I had purchased to benchmark. It's still 100% functional. I can measure it and we can get a feel for what you feel is the best in class.If you feel there are other characteristics I should have been measuring, feel free to provide them. The only reason I started to measure them was after seeing Dave and others touching leads, it seemed like a EE would do better. There's just too many errors.Another thing the OP could do is measure the pulse times they see with a scope, using their drag method, or what ever it is they are doing that is causing them to need an immediate response. I'm pretty old and slow now so the 150ms Amprobe may be fine for me.Maybe just take what ever packages you use and measure the times with a scope. Maybe try some different techniques.

author: Fungus
author_rank: Super Contributor
timestamp: August 03, 2020, 11:40:36 am
content: Quote from: SolderSucker on August 03, 2020, 10:41:48 amSo... what meter are you currently using?

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 03, 2020, 11:53:24 am
content: Quote from: Fungus on August 03, 2020, 11:40:36 amExtech EX330.It's been getting increasingly erratic over the past few months and I've spent a lot of time reading up about troubleshooting it, etc - unfortunately despite cleaning the contacts, checking for bad components, etc I've not got anywhere.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 03, 2020, 11:55:19 am
content: Quote from: bd139 on August 02, 2020, 04:53:30 pmI get what you are trying to say. At least for me the name, "EEVBlog Electronics Community Forum" instills a vision of low energy circuits, normally below a couple of KV. If it were the "... Industrial Electrical Community ...", I may be more inclinded to think about safety. I also envision that people involved with electronics are far more capable of working with complicated test equipment than an electrical worker.The two meters I use (Brymen BM869s and Fluke 189) both have separate ACV and DCV positions. A good example for you would be Dave's 121GW. It has a single position for both and it also remembers the last settings selected. Personally, after having used this feature for a few years now, I really like it. Brymen offers an automotive meter, and they only support storing the settings for certain features. It's really a shame as I would only use it with a particular setup and of course, it differs from the default. So every time to use it, you have to change the settings. Really an odd thing.

author: Fungus
author_rank: Super Contributor
timestamp: August 03, 2020, 12:08:43 pm
content: Quote from: tooki on August 03, 2020, 11:18:13 amIt's true! Noticeably slower then my Aneng.Quote from: tooki on August 03, 2020, 11:18:13 amThey're made alotmore meters than that. eg. My Fluke 27 came after the 8060A and is much slower then even the 101.My Aneng 860B+ is quite hard to fool in the "bang the probes together" test with gold plated probes (probesdomake a difference to this). My Brymen seems unfoolable.My Brymen is rated at 0.1mS. Joe's measurements were 1ms for the Aneng (Kasuntest KT6000 in his sheet) and 40ms for the Fluke 101.That gives you an idea of what sort of response time is needed.

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 12:18:18 pm
content: Quote from: joeqsmith on August 03, 2020, 11:34:54 amIndeed, I think it also depends on the application. The guy in the video disliked the 87V’s 50 ohm threshold, which I suspect is part of why that meter works well even with terrible probes. When tracing wires and other situations where what you’re excluding is open connections, that works great. But I can see how if you’re using it to search for dead shorts on a PCB with components on it, 50 ohms might be an issue if alternative paths appear thataren’tdead shorts but are below that threshold. (I suppose this is a good time to remind folks that the 87V, like essentially all Fluke handheld meters, is designed much more with electrician use in mind than electronics.)I love the continuity in my Keithley 2015: when you enter continuity mode, it first has you set the threshold. (The default is 10 ohms IIRC.)One other continuity feature to test: As I understand it from the manual, the 87V and similar Flukes not only test continuity, butdiscontinuity, too, in that if you’re testing a normally closed circuit and there’s a tiny transientopen, it’ll also latch that and silence the beep long enough to hear it. (The manual expressly says it will catch “opens and shorts lasting as little as 1ms”, and obviously the latched beeper latches for way longer than 1ms, so it’d have to latch the opens, too. Very informal testing by whacking the only momentary SPDT switch I have seems to confirm this behavior. My Keysight U1252B has it too, but the Keithley 2015 and Aneng AN8008’s latching continuity latches right over the intermittent opens.)

author: Miti
author_rank: Super Contributor
timestamp: August 03, 2020, 12:24:52 pm
content: I'm very pleased with my Fluke 179 speed.

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 01:39:41 pm
content: Quote from: Fungus on August 03, 2020, 12:08:43 pmEww, gross!Quote from: Fungus on August 03, 2020, 12:08:43 pmWell sure they have. But with the apparent exception of the 101 (and other 100 series), and 12E/15B/15B+/17B/17B+/18B+, all of the halfway recent models have great continuity, with most being specced at 1ms, and some (like the 110 series and 280 series) at 500μs. (The Fluke 10 series, except for the 12E/15B/15B+/17B/17B+/18B+, are even specced at 250μs.) While randomly choosing manuals to look at, it stuck out to me that on models with good continuity, Fluke specifies the response time, while in those with not so good response time, they just don’t state it at all!I still think it’s fair to say that Flukenowhas a reputation for good continuity, even if there are apparently a number of models that don’t actually fulfill it. All of the current models with slow continuity appear to be inexpensive Asia-only models. All the worldwide models have the fast continuity. You have to go back quite a few years to find a worldwide model with slow continuity.Quote from: Fungus on August 03, 2020, 12:08:43 pmAye. While there is no excuse for slow continuity IMHO, I wonder if the reason we don’t see very many meters with response times below, say, half a ms, is to filter spurious beeps or bounce or something?I wonder if there are any projects out there for latched continuity testers that do both intermittent shorts and opens, and what timing parameters and behaviors they chose? (The “ultimate” continuity tester in that video is not latched, and would be great for some uses but terrible for others, I’d think.)(FWIW, I never said there weren’t other meters with good continuity. There absolutely are! I’ve been considering grabbing an AN860 just to check it out, since it seems to perform very well on tests and my experience with the AN8008 has been mostly positive, too.)

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 01:44:40 pm
content: Quote from: joeqsmith on August 03, 2020, 11:34:54 amOh yeah, I should add that to me, the 87V’s continuity is great in that it seems to strike a good balance between being highly sensitive and responsive, yet tolerant of non-ideal conditions, without producing spurious signals, etc. The guy in the video clearly hasverydifferent priorities (the need for which he doesn’t go into in too much detail) that differ from mine (and, I suppose, of many people, give how most multimeters are designed).

author: AVGresponding
author_rank: Super Contributor
timestamp: August 03, 2020, 08:23:57 pm
content: Quote from: bd139 on August 02, 2020, 10:59:34 amMy UT139C isalmostas fast as my 87V.Gonna fly the flag here (really, moi?) and also recommend some nice vintage Black Star meters, 32XX series. I have a 3210MP (mains Powered) and a 3225, both are pretty good.My worst meter for continuity is my Mastech 2108A, it's almost inaudible in anything except a silent environment. Luckily I only need it for the current clampiness.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 04, 2020, 01:38:44 am
content: Quote from: tooki on August 03, 2020, 12:18:18 pmShort resistance: 52 ohmsOpen resistance: 94 ohmsOpen circuit voltage: 7.325VShort circuit current: 1.0025maMax freq at 50% DC: 3.9HzMin pulse width at 2Hz: 1.5msDetecting an open circuit appears a bit faster. It would still pick it up at 1ms.IMO, these numbers IMO are fine, plus it's latching if you like that sort of feature.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 04, 2020, 09:31:07 am
content: Update: thanks to all of the recommendations and advice in this thread I decided to buy the UNI-T UT139C (I just couldn't afford a decent Fluke) - the 139C is great, very quick on the continuity response time. My only minor criticism (which I knew about before I bought it) is that the continuity buzzer continues to beep for a fraction of a second after a probe is removed from whatever is being tested. So far that's not been a major problem.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 04, 2020, 12:09:48 pm
content: Congratulations on your purchase! The UT139C is an excellent meter.

author: indman
author_rank: Super Contributor
timestamp: August 04, 2020, 12:30:10 pm
content: Now in the official store on Ali, they began to sell another revision UT139C of the board with a processor in the form of a blob and bad layout of the board. Sаfety has deteriorated. Keep this in mind.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 04, 2020, 12:35:11 pm
content: Quote from: indman on August 04, 2020, 12:30:10 pmUseful to know, thanks. I got mine from Amazon UK so I guess it's 'older' stock. I guess I could take it apart and have a look but not right now .........

author: Fungus
author_rank: Super Contributor
timestamp: August 04, 2020, 01:41:24 pm
content: Quote from: indman on August 04, 2020, 12:30:10 pm... andTHISis the problem with Uni-T. You never know what's going to be inside one.

author: bd139
author_rank: Super Contributor
timestamp: August 04, 2020, 02:14:35 pm
content: Yep. They sell different versions in different markets as well. For example the classic UT61E. There was a european market version with proper protection that was £120 or so. The non European market one was £25. Of course everyone shut their eyes and imported the cheap ones on ebay and amazon and the CE certifiable ones had too much competition thus were restocked.It's a race to the bottom that ends in your personal safety suffering.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 04, 2020, 03:32:27 pm
content: In the interests of science and curiosity I took the back off mine and grabbed a photo - looks like I have the inferior 'blob' (COB) version - should I try for a refund and seek out the 'better' model?BTW, as it can't be made out in the photo, the 8 pin chip at U3 has the following markings:T24C02A19m0F3Board photo below (note: there's no components on the other side, I removed it and checked).

author: HKJ
author_rank: Super Contributor
timestamp: August 04, 2020, 03:40:20 pm
content: Quote from: SolderSucker on August 04, 2020, 03:32:27 pmIt looks fairly decent at a quick glance. It has 3 MOVs, and two PTCs, the fuses are ceramic, but the 10A probably too small for CAT III 600V.

author: exe
author_rank: Unknown
timestamp: August 04, 2020, 05:21:22 pm
content: I didn't read the whole thread, but I want to comment. If continuity testing is all you need, then I recommend and aneng 8002 or 8008. They are, in my opinion, instant.

author: schmitt trigger
author_rank: Super Contributor
timestamp: August 04, 2020, 05:39:29 pm
content: Warning, Warning! Addiction Alert!If you want to become a true, red-blooded EEVBlog member, you will require to own *at least* two meters.Some members here have a dozen in their collection, and expensive ones to boot!In addition to pedestrian instruments like 400 Mhz oscilloscopes, and vector network analyzers.You have been warned.

author: AVGresponding
author_rank: Super Contributor
timestamp: August 04, 2020, 06:40:25 pm
content: Quote from: HKJ on August 04, 2020, 03:40:20 pmYes, it's a BS1362 type, and I can't see how that can exceed CAT I, as the maths implies a required breaking capacity of 333A @ 600VAC for CAT II and 3kA @ 600VAC for CAT III.A brief outline of CAT ratings as they apply to multimetersDatasheet of the fuse in questionMine doesn't have a BoB, seems to be rev 4 with the OP's being rev 5, but looks the same re the input protection:

author: rsjsouza
author_rank: Super Contributor
timestamp: August 04, 2020, 07:24:08 pm
content: I reviewed this meter a while ago (attached photo) and it did not have the blob, although the input protection looked fairly similar and the 10A fuse, although looking like a BS1362, it was instead rated for 600V.I don't see a problem with the blob per se and, if nothing else changed, it should still be a good meter. This is very different than the shameful case of the UT61E model mentioned before, where the revisions werw quite different in the input protection.

author: exe
author_rank: Unknown
timestamp: August 04, 2020, 07:58:34 pm
content: Quote from: rsjsouza on August 04, 2020, 07:24:08 pmWow, are we discussing continuity testing of high-energy circuits?I have three types of DMMs in my drawer: cheap and fast anengs for 95% of work, K2000 when I need precision, and121GWlidl multimeter for mains.

author: indman
author_rank: Super Contributor
timestamp: August 04, 2020, 08:15:56 pm
content: From my practice, Chinese multimeters with a blob processor deteriorate much more often. The blob is much more sensitive to PCB deformations, shocks and overloads. I also see that placing all the parts on the same side of the board does not increase the reliability of the entire circuit. I would like to see the reverse side of the new board to see how well the mode selector tracks are routed. This is just my opinion, you may not agree with him.

author: AVGresponding
author_rank: Super Contributor
timestamp: August 04, 2020, 08:39:38 pm
content: Quote from: rsjsouza on August 04, 2020, 07:24:08 pmIt is a BS1362 type. If you look at the datasheet, which is for the actual fuse that came fitted in mine, it's rated for a 200A breaking capacity @ 600VAC, and 10kA @ 250VAC.I personally wouldn't use it on anything other than SELV stuff, I have Flukes for serious work. It's perfectly adequate as an electronics hobbyists meter.

author: Gyro
author_rank: Super Contributor
timestamp: August 04, 2020, 09:01:05 pm
content: Quote from: exe on August 04, 2020, 07:58:34 pmJust what I was thinking. This doesn't seem to be part of the OP's requirement.I don't know why people don't just build simple continuity testers. For example, the attached one (from EPE - Everyday Practical Electronics back in 1989) has a threshold of around 1R for continuity, 1M for isolation. I built one based on this circuit back then and it still works well to this day, as far as can be perceived, its response is instantaneous. Probe voltage is around 200mV, with reasonable input protection - not mains (although if safely constructed, it would probably smoke rather than exploding - especially if fusible resistors were used). I've always remembered this article as an example clarity - an ideal project for beginners that's actually useful.I tweaked the audio circuit to two tones - continuity and isolation, and to start ticking quietly after about 30 seconds idle time as a battery saving reminder. It lives on the shelf above my bench to this day, I always use it in preference to a DMM if I'm trace out a board due to the resolution and instantaneous response. Of course, the range of available low current opamps is much wider these days - I can't remember what I used, not an LM308, probably something I had to hand.Edit: The only time I've had it apart in the last 30 years was to add a front panel label and switch the input jacks to shrouded ones so that it could accept modern test leads.

author: SolderSucker
author_rank: Regular Contributor
timestamp: August 04, 2020, 09:17:55 pm
content: Quote from: Gyro on August 04, 2020, 09:01:05 pmOP here - in my case I was looking to replace my increasingly erratic Extech EX330 - I needed a relatively cheap and relatively basic meter that must have a fast continuity test. I only test boards running at 5 volts DC or lower (well, okay, also +12 volts DC for old sound circuits, -5 VDC too). That's pretty much it.

author: bd139
author_rank: Super Contributor
timestamp: August 04, 2020, 10:08:39 pm
content: It’s fine then.Incidentally I repaired my washing machine and rewired my house with a very dodgy UT61E.

author: AVGresponding
author_rank: Super Contributor
timestamp: August 05, 2020, 05:15:29 am
content: Quote from: bd139 on August 04, 2020, 10:08:39 pmImpressive you got so much wire out of it. Personally I'd have used 2.5mm2LSF T+E.

author: Fungus
author_rank: Super Contributor
timestamp: August 05, 2020, 06:11:23 am
content: Quote from: SolderSucker on August 04, 2020, 03:32:27 pmAny 8-pin chip inside a multimeter is probably an EEPROM that stores the calibration data.(unless it's a Hioki)

author: bd139
author_rank: Super Contributor
timestamp: August 05, 2020, 08:34:24 am
content: Quote from: AVGresponding on August 05, 2020, 05:15:29 amTo be fair the wire in the washing machine was better than 1950s stuff in the walls

author: rsjsouza
author_rank: Super Contributor
timestamp: August 05, 2020, 02:24:03 pm
content: Quote from: Gyro on August 04, 2020, 09:01:05 pmI didn't start it. My message was intended to clear a question about the front end of the revised UT139C, nothing less.Quote from: AVGresponding on August 04, 2020, 08:39:38 pmThanks. I thought the BS1362 types were only 250V rated.

author: AVGresponding
author_rank: Super Contributor
timestamp: August 05, 2020, 05:11:57 pm
content: Quote from: rsjsouza on August 05, 2020, 02:24:03 pmFull specifications are only available from the BSI or third party agents for not inconsiderable sums of money.Since it's not something that directly concerns my work, I can't get my employer to pay the £170 or so that it costs, unlike with other things to do with fire alarm regs, emergency lighting regs, general wiring regs, building regs etc.Lacking the intention to part with said cash, I'm forced to speculate; either the 600VAC rating is part of the BS1362 (1973) spec, perhaps pertaining to possible phase-phase faults, or it's simply the manufacturer (Bussman in this case) has had them additionally certified so they can be used in other applications, such as marginal Chinesium DMMs...

author: AlexTee
author_rank: Contributor
timestamp: November 07, 2021, 06:40:03 pm
content: Could you please watch this video and tell me if this a not an unusual behavior for a cheapo DMMs like UT161D (the certified version of UT61D+) to momentary interrupt beeping in continuity test? As I understand, it is quite slow at determining resistance, which causes beep interruption until the reading drops low enough to engage back the beeping to indicate a short circuit. My concern is that it stops me from reliably judging about circuit condition, because this brief interruption would make me think the PCB has bad contact. Each time I have to guess whether it was PCB or meter.Would you keep such DMM or better get rid of it and invest in more reliable product?https://youtu.be/0HC-WeQ5inA

author: Fungus
author_rank: Super Contributor
timestamp: November 08, 2021, 07:43:41 am
content: Quote from: AlexTee on November 07, 2021, 06:40:03 pmNo it isn't. Lots of meters do it. It can be dirt on the probes, on the DUT, whatever...Quote from: AlexTee on November 07, 2021, 06:40:03 pmSome meters latch the signal and make itsoundcontinuous. I'm sure the owners are happy but which version is the truth?

author: AlexTee
author_rank: Contributor
timestamp: November 08, 2021, 07:53:13 am
content: Quote from: Fungus on November 08, 2021, 07:43:41 amThere is no dirt on probes, they are brand new, deliberately cleaned gold plated ones. If there was a dirt, it won't latch the sound immediately. Hm, I thought it is obvious from the video, that the problem is not with probes at all, but with slow measurement of resistance, which kicks in shortly after intial latching. And when it starts measuring, for some reason it starts off by jumping to higher reading, which causes sound interruption, then dropping down to 0.And when you state, that a lot of meters do that, hm, at least other 2 meters I own never interrupt beeping unless probes are released.

author: Fungus
author_rank: Super Contributor
timestamp: November 08, 2021, 08:13:32 am
content: I watched the video. Yeah, that meter is weird.

author: AlexTee
author_rank: Contributor
timestamp: November 08, 2021, 08:23:09 am
content: Quote from: Fungus on November 08, 2021, 08:13:32 amYeah, that's what I mean. While being a minor issue it still annoys me. Imagine you're testing a complex PCB path, each time the sounds breaks, it triggers you into false assumption there might be something wrong with the PCB itself. I doubt I can get used to it. Probably will keep this one as a backup and invest in a more reliable product.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 08, 2021, 11:18:20 am
content: Not only the break is bad, but its latch is terribly long - I can see you release the probes and the meter still beeping for 1/3 to 1/2 second.I would definitely consider returning the meter - since there are no other tests around for either the UT161D or the UT61D+, it is impossible to know if this is intrinsic to this version of the meter or a defect on your unit.

author: AlexTee
author_rank: Contributor
timestamp: November 08, 2021, 12:27:15 pm
content: Quote from: rsjsouza on November 08, 2021, 11:18:20 amWell, this is a bit tricky. If I release the probes just before the resistance measurement procedure kicks in, the beeping stops almost immediately (but very tiny delay's still present).So, probably, there are two internal software routines invoking one after the other: the first one is executed whenever a short circuit is detected (via a hardware interrupt trigger implemented using external pull up on some I/O port), and then it jumps to the other routine, which executes much slower compared to the first routine. The cycle starts over whenever the second routine is exited (when reading returns to OL) with the first fast-responding routine ready to kick in next time a short circuit is re-detected. The manual states that the buzzer should come on if the tested circuit resistance is <50 Om, so I probed a 15 om resistor, but the meter didn't invoke the first routine, and proceeded with the second one, causing a significant delay. The user manual doesn't state the response time, and now I can see why. They just circumvented the hardware limitations by introducing two-stage continuity test and we as users of this gimmick should consider it as a feature, not a bug. Please, avoid this meter at any cost. I'm lucky I paid only 40 USD for this BS.Here is the new self-explanatory video:https://youtu.be/Daagvz40it0I wonder how more expensive DMMs from top brands behave when there's a small resistance in place. Do they still respond fast enough? Please, test on your meters, this is an interesting topic to discuss.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 08, 2021, 04:30:58 pm
content: Quote from: AlexTee on November 08, 2021, 12:27:15 pmIt is not uncommon to see meters being able to have a working continuity mode with values larger than 0Ω and I can tell the ones I have from Keysight, Fluke, Brymen, etc have a hardware-implemented latch to indicate these values in the buzzer and, in some models, in an LED as well. So, the UT161D resembles the AN870/RM219 and the UT61E, where at 0Ω (or very near) the response is absolutely instantaneous but for values above a few Ω, you can clearly notice the buzzer is slower and, in the case of the AN870/RM219, it also lingers a bit after the probe release (the UT61E releases the buzzer immediately). However, both the UT61E and the AN870/RM219 do not have the stupid double beep.However, brand name and price are not the only factors for a decent implementation or not. The Fluke 101 and the Amprobe AM530 are top tier brands but are very slow, while the Richmeters RM113D is quite fast (including a LED anunciator). So, your best bet is to look around for tests on the internet and see what it suits you.

author: AlexTee
author_rank: Contributor
timestamp: November 09, 2021, 08:42:37 am
content: rsjsouzait comes out, there was a dedicated topic in regards to 61d+, and there are some nice findings done by other users in recent posts:https://www.eevblog.com/forum/testgear/uni-t-ut61d-continuity-test-issue/msg3721273/#msg3721273