Old DMMs - Page 1
Forum section: electronics / testgear

author: Trader
author_rank: Frequent Contributor
timestamp: May 04, 2021, 01:04:15 am
content: I wonder what are the first handheld DMMs with most of the functions of modern DMMs, like Capacitance (and maybe Frequency counter).HP 974A - no capacitanceFluke 80xx, 77 - no capacitance

author: Trader
author_rank: Frequent Contributor
timestamp: May 04, 2021, 01:13:05 am
content: HP 972A / 973A - has capacitance (first one from HP?)Tektronix?

author: wizard69
author_rank: Super Contributor
timestamp: May 04, 2021, 04:36:00 am
content: Quote from: Trader on May 04, 2021, 01:04:15 amwhy do you consider capacitance a feature of modern DMM's? It seems like a very arbitrary way to categorize multimeters. For instance some consider temperature measurement mandatory but that has never been the primary domain of multimeters. In both cases there are better instruments available for both temperature and capacitance measurements.I know I'm an old guy that started out with little but man I would have died growing up just to have a volt meter much less a multimeter.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 04, 2021, 01:51:30 pm
content: Fluke 87 which was introduced in 1988 or so has capacitance.

author: Trader
author_rank: Frequent Contributor
timestamp: May 04, 2021, 02:39:27 pm
content: Quote from: wizard69 on May 04, 2021, 04:36:00 amI realized that most of the features from a modern DMM are present in the old DMMs, but not the Capacitance.I consider measuring Capacitance more relevant in electronics development and maintenance than temperature, but ok.

author: gdewitte
author_rank: Unknown
timestamp: May 04, 2021, 02:55:12 pm
content: May not be the oldest, but the Heathkit IM-2320 has capacitanceandhFE.

author: Fungus
author_rank: Super Contributor
timestamp: May 04, 2021, 03:18:15 pm
content: Quote from: Trader on May 04, 2021, 02:39:27 pmI'm guessing you never heard of the "kick test". It's how people used to measure capacitance with old analog meters.It also works with digital meters that have an analog bar graph, eg. My Fluke 27 doesn't have capacitance on the dial but the manual has a procedure/tables for using it to measure capacitance.

author: Trader
author_rank: Frequent Contributor
timestamp: May 04, 2021, 05:37:54 pm
content: Quote from: Fungus on May 04, 2021, 03:18:15 pmI know this test, thank you for remind it. But I'm talking about Capacitance Measurement, this test doesn't "measure capacitance" only check if the capacitor seems to be working.

author: Fungus
author_rank: Super Contributor
timestamp: May 04, 2021, 06:16:45 pm
content: Quote from: Trader on May 04, 2021, 05:37:54 pmOK, but I wouldn't draw the line of "Modern DMM" at the point where capacitance appeared. It seems a bit arbitrary. How about when they started using microprocessors and doing autoranging? That seems like a bigger leap to me.Also: Are we including bench DMMs or only handhelds?

author: Trader
author_rank: Frequent Contributor
timestamp: May 04, 2021, 08:13:33 pm
content: Quote from: Fungus on May 04, 2021, 06:16:45 pm"Only handhelds". Maybe I didn't express it correctly, but my curiosity is: when a Handheld DMM was 'capable' to do All or the Majority of the measures of today's meters.I think one of the last features implemented was the Capacitance measuring, maybe the HP 973A was the first handheld DMM with all the most important measures we see today.http://literature.cdn.keysight.com/litweb/pdf/5967-6368EN.pdfhttps://doc.xdevs.com/doc/HP_Agilent_Keysight/HP%20972A,%20973A%20Instruction.pdf

author: J-R
author_rank: Super Contributor
timestamp: May 04, 2021, 08:17:42 pm
content: Even on modern handheld DMMs I would propose capacitance and frequency measurement functionality is somewhat over-rated.To properly measure a capacitor you need to be able to set the frequency. Furthermore what you really want is to be able to TEST the capacitor so now you want an ESR meter (or an LCR meter with that feature).For frequency measurements most DMMs top out in the hundreds of kHz and have very limited resolution, maybe 3-4 digits. You also have no idea what the waveform looks like and it is trivial to fool them into displaying a garbage result, such as 0. So even one of the toy scopes will be better in that regard and for any amount of accuracy you will want a frequency counter.

author: mansaxel
author_rank: Super Contributor
timestamp: May 05, 2021, 04:34:01 am
content: I would side with the posters stating that capacitance and frequency aren't such game changers as sales persons would have you believe. I think that the 8020 is the handheld DMM that set the standard for what a handheld DMM should be, and the change in performance, at sensible price point, offered by that meter is the interesting point in the DMM evolution. The rest is just incremental.I divide my DMM hours between a Gossen MetraHit 25, a -hp- 974A and a Fluke 8060. But I won't measure capacitance with either. That's the job of the DE-5000 (repairing gear means looking at caps in several ways; first as consumables, second in terms of ESR et c.). And for frequency, one has to go benchtop. For starters it is probably hard to properly design a Cat III meter with a reference input, and a frequency counter that won't take 10MHz ref in, is hopelessly left behind./Måns, has not really gathered courage to test capacitors the old way, using the mains and an analog VOM...

author: Martian Tech
author_rank: Regular Contributor
timestamp: May 05, 2021, 04:58:38 am
content: Since this thread has already pretty much gone off the rails, I'll mention the Wavetek Meterman 27XT. Although not the first to provide "modern" functions, it does have some interesting functionality: capacitance, inductance, logic levels. But wait, there's more! It measures frequency up to 20MHz. Unfortunately, it's only a 3.5 digit meter. But I just checked mine with a 10MHz OCXO and it reads 10.00/10.01. Not bad for a 20 year-old handheld meter that's never been calibrated since I bought it

author: Performa01
author_rank: Super Contributor
timestamp: May 05, 2021, 07:23:11 am
content: METEX 3630/50 (3.5 digits) and METEX 4630/50 (4.5 digits, 0.05 %) have been available in the 80s of last century already.The "30" version had capacitance measurement (2 nF to 20 µF) and the "50" version had frequency measurement (specified to 200 kHz, but actually worked up to a couple MHz) on top.These were good meters and still sold some 20 years later under various different brand names. No autoranging and no RMS measurement though.These meters also have a feature that you won't find in modern DMMs, let alone bench multimeters: a very low input current of just a few pA. Together with the 10 Mohms input impedance, this makes for a very useable pA-meter.

author: Muttley Snickers
author_rank: Unknown
timestamp: May 05, 2021, 07:43:19 am
content: They also had logic, min/max and a pc interface as well which were some of the reasons I bought one back in 1992.https://www.eevblog.com/forum/testgear/is-metex-a-quality-brand/?action=dlattach;attach=288856;image

author: HKJ
author_rank: Super Contributor
timestamp: May 05, 2021, 07:52:09 am
content: Quote from: Performa01 on May 05, 2021, 07:23:11 amA very high input impedance is present on both handheld and bench DMM's today. On bench meter you can usually switch between 10Mohm and high, on handheld meters it is often always present in the mV DC range (On some high end meters it is switchable).

author: Performa01
author_rank: Super Contributor
timestamp: May 05, 2021, 12:25:30 pm
content: Quote from: HKJ on May 05, 2021, 07:52:09 amI'm not sure what you want to express with that?I was not talking about input impedance, but input (bias) current. And this doesn't change, whether you have some 10 meg resistor across the input or not.If I claim that no bench DMM comes even close to the old Metex 4650, you may expect that I have measured dozens of them, from venerable Schlumberger 7150 plus up to Keithley 2001. The best of them have a bias current of some 30 pA, but none of them comes close to <5 pA like the old METEX does.Input bias current is especially bad on the meters with alleged high input impedance, like >10 Gohm for most bench DMMs in the low voltage ranges.And this is the trap for youngplayers: you might think you can use such a DMM like an electrometer (for low voltages at least), but that's not the case, not by a long shot.I also have checked several more modern handhelds. The "high impedance range", if present, often is only some 1 Gohm, but the really important thing is the (more or less constant) input bias current anyway. None of the more modern DMMs I've come across so far had nearly as low a bias current that it would be able to compete.

author: Performa01
author_rank: Super Contributor
timestamp: May 05, 2021, 12:28:57 pm
content: Quote from: Muttley Snickers on May 05, 2021, 07:43:19 amYes, but that's the "CR" variant, which was only available in the late 80s or even early 90s.The venerable 4650 (without CR) did not have the bar graph, no min/max and no PC interface.

author: Trader
author_rank: Frequent Contributor
timestamp: May 05, 2021, 03:05:07 pm
content: Very nice to know about these very good "first DMMs", I never heard before, thanks for sharing.Capacitance could be not so important to some people but is very handy for a quick test. But if you really want properly check the capacitor, you not only need a scope and awg, but also submit it to the Max Voltage (at least 90%) to certify if all specs still fine; this requires a much more specialized (and expensive) tester.Other important features from today's high-end DMMs are: TRUE-RMS with an AC bandwidth of at least 20 kHz.One of the first DMMs to implement that seems to be the:- Yokogawa 7537 04 #https://almateks.com/doc/dmm-e-150.pdf(page 9), and the- HP 973A #http://literature.cdn.keysight.com/litweb/pdf/5967-6368EN.pdf(page 2)As a plus, they have Bargraph and Dual Display.(I can't find the released year, 1994?)

author: Trader
author_rank: Frequent Contributor
timestamp: May 05, 2021, 03:21:45 pm
content: Quote from: Performa01 on May 05, 2021, 07:23:11 amMaybe the "winner"METEX 3630/50 (3.5 digits)http://archive.retro.co.za/archive/electronics/Metex%20M3600%20B%20Series%20Operating%20Manual.pdfhttps://www.radiomuseum.org/r/metex_digital_multimeter_m_3630_d.htmlMETEX 4630/50 (4.5 digits, 0.05 %)http://elektron.pol.lublin.pl/users/elekp/labor_instr/METEX_M-4650CR_Manual.pdf

author: kleiner Rainer
author_rank: Regular Contributor
timestamp: May 06, 2021, 09:20:39 am
content: My contender: Protek/HungChang/Voltcraft 506. MAX134-based 3 3/4 digits, true RMS, dual display, bar graph.https://www.radiomuseum.org/r/hungchang_protek_506.html?language_id=2Bought mine around 1995. Does capacitance (100uF max.), inductance (100H max), frequency up to 10MHz, dB, logic probe, temperature (type K), signal output (2kHz, 4kHz, 8kHz), serial interface and backlight.Greetings,Rainer

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 09:49:33 am
content: Quote from: kleiner Rainer on May 06, 2021, 09:20:39 amNow the timeline is getting close to the Fluke 189 or 89-IV. I do not now when the 89-IV was released, but the third revision of the manual is from 1999 (The 189 was released around that time and was basically a rebrand of the 89-IV).And that meter do not look old compare to a modern DMM:

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 10:05:43 am
content: Quote from: HKJ on May 06, 2021, 09:49:33 amThe original Fluke 87 has almost the same features as the 87V. The 87's manual is dated "August 1988".

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 10:41:22 am
content: Quote from: Fungus on May 06, 2021, 10:05:43 amBut that meter lacks capacity and temperature.Other features of the 187/189 was Autohold, AC+DC and computer connection

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 11:09:51 am
content: Quote from: HKJ on May 06, 2021, 10:41:22 amI had the original 87 around 89 or so. It doesn't have temperature but does have capacitance but only to 5 microfarad not 10 milifarad like the 87V. Although the 87 had lifetime warranty but Fluke only fixed my display problem once. The second time they said they couldn't fix it and offer me $100 toward a new meter. So I bought the 189 which was around 2005 at the time and shortly after I bought the 189 Fluke contacted me for an interview about a new DMM they were working on which became the 289 now. They had it simulated on a laptop computer so I didn't know the 2 most drawback of the 289 is the full dot matrix display contrast is so low and boot up time is too slow too. I have the 289 but I rarely use it neither do I use the 189 very much and in fact I use the 87V daily.

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 11:24:24 am
content: Quote from: HKJ on May 06, 2021, 10:41:22 amIt has capacitance:I didn't realize "temperature" was a requirement now.

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 11:34:50 am
content: Quote from: Fungus on May 06, 2021, 11:24:24 amI missed that.Quote from: Fungus on May 06, 2021, 11:24:24 amIt depends on what you use the meter for, in electronic it is useful to check the temperature of components and heatsinks (Today A thermo camera is sometimes better).

author: Caliaxy
author_rank: Frequent Contributor
timestamp: May 06, 2021, 12:06:56 pm
content: Quote from: HKJ on May 06, 2021, 09:49:33 amIMO Fluke 189 looks much better (and it’s much more ergonomic) than the Brymen on the left. Just look at those rotary dials. Too bad Fluke discontinued it...

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 01:07:12 pm
content: Quote from: Caliaxy on May 06, 2021, 12:06:56 pmThe Fluke 87IV was really "peak Fluke".That's the point where people started screaming and Fluke had to go back to the 87III (with a couple of mods) and call it the 87V. They've been stuck there ever since. They can't touch the 87V in any way and they can't make a meter that competes with it in price or features.I recently got a pristine 187 for 200 bucks (still had the screen protector on it). It's the same as a 189 but without the internal data-log RAM and leaky supercap. I didn't need it but it seemed too good to pass up. All the measurements agree perfectly with my 50,000 count BM857s (to within a digit...) I guess I've now got all the meters I can possibly use for the rest of my life.(I'll leave the others to fight over the 87Vs, I don't want one...)Here they are measuring my 2.048V reference:The Brymen screen is much more contrasty than the Fluke though.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 01:08:17 pm
content: Quote from: kleiner Rainer on May 06, 2021, 09:20:39 amPretty decent contender, maybe one of the best low-budget at that time.Quote from: HKJ on May 06, 2021, 09:49:33 amEven today several people consider the Fluke 189 or 89-IV better than Fluke 289.Yes, Fluke 89 IV and Fluke 87 IV become 189 and 187. The 187 don't have the Supercapacitor Leaking/Corrosion Issue, excellent choice.http://userequip.com/files/specs/1220/87_89iv_User_Manual.pdfQuote from: Fungus on May 06, 2021, 10:05:43 amMaybe first release was in 1996:https://www.eevblog.com/forum/testgear/i-need-to-know-the-history-of-fluke-87-(-1998-2010-)/

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 01:12:13 pm
content: Quote from: HKJ on May 06, 2021, 10:41:22 amYou can see the picture, has capacitance.https://dam-assets.fluke.com/s3fs-public/87______umeng0800.pdfAC+DC is a very handy feature.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 01:25:37 pm
content: Quote from: Caliaxy on May 06, 2021, 12:06:56 pmI missed this for a couple of hours, some people have no idea what they have at hand.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 01:36:49 pm
content: I missed this for a couple of hours, some people have no idea what they have at hand.Well but the fuses are quite expensive. Would cost you around $25 for the 2 fuses and 4 AA batteries!

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 01:37:12 pm
content: Quote from: Trader on May 06, 2021, 01:08:17 pmThe manual says 1988:https://manuals.solidsignal.com/87-5.pdf

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 01:38:35 pm
content: Quote from: Trader on May 06, 2021, 01:25:37 pmFWIW my guy also has a 189 that's missing one of the spring contacts in the rotary switch but otherwise works perfectly.If anybody's interested in fixing it or has a 189 that needs a new PCB then let me know...

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 01:40:19 pm
content: I had my 87 in 1989 so the introduction date of 1988 is about right not 1996.

author: Shock
author_rank: Super Contributor
timestamp: May 06, 2021, 01:52:55 pm
content: The transition with Flukes was the Fluke 27FM then the Fluke 80 series with capacitance. Both had optional temperature probes, a 6kV and 40kV high voltage probe and LoZ adapter.I have the Fluke 77, 27FM, 87, 87V, 112, 117 and 189 among others. The 87V though is the best Fluke for most people in my opinion (as a modern daily driver). If you like military layout and can live with fewer digits then the FLUKE 27FM . Eventually you'll get an LCR, leakage or ESR meter, so testing capacitance on a multimeter is not so important. Measuring low and high resistance will also become fairly redundant, it's mostly for portability and troubleshooting convenience.As a newer model, something with everything, the Brymen BM869s is a great option.

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 02:03:59 pm
content: Quote from: Shock on May 06, 2021, 01:52:55 pmProblem: I can buy 3xBM857s for the same price.

author: Shock
author_rank: Super Contributor
timestamp: May 06, 2021, 02:21:07 pm
content: I didn't necessarily mean new. But if you were looking for new and to optimize your dollar, Brymen for sure.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 02:36:21 pm
content: The Fluke 87V I use daily (in fact it's the second one, the first one someone stole it) was paid by my employer but if I have to pay for my own meter I think I still use an 87V. I have the 189 and 289 but I don't like using them for everyday use on the production floor.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 03:34:20 pm
content: Quote from: Fungus on May 06, 2021, 01:37:12 pmYou are right and the manual says "Rev.8, 4/97", which could be even before 1988.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 03:39:47 pm
content: Quote from: BeBuLamar on May 06, 2021, 02:36:21 pmWhy, not sturdy enough?

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 03:57:42 pm
content: They are about the same toughness as the 87V (because it's only the 87V and not 87V Max) but the 189 battery life is too short although it doesn't have the problem with the super capacitor but a battery life of 70 hours are short. The 289 is better in this respect but still significantly shorter than the 87V. The 289 is also slow to turn on and slow to autorange on resistor. The contrast is poor so that I almost always have to use the backlight which shorten the battery life. Also being used to other Fluke meter whenever I tried to turn on the back light I hit the power button and turn it off and then I have to wait for it to boot up again.

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 03:58:20 pm
content: Quote from: Trader on May 06, 2021, 03:34:20 pmLook at the list of copyright dates below

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 04:00:33 pm
content: Quote from: BeBuLamar on May 06, 2021, 03:57:42 pmI have used both 189 and 289 with a computer to log data, my experience was that 289 had the shortest battery life.

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 05:27:53 pm
content: Quote from: HKJ on May 06, 2021, 04:00:33 pmThe 189 has an optional battery compartment extender to let it use C cells.

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 06:19:43 pm
content: Quote from: Fungus on May 06, 2021, 05:27:53 pmNot really a good option, C cell usually cost more than AA also when comparing capacity.I have later updated to a pair of 34461A, no battery changing with them.

author: Fungus
author_rank: Super Contributor
timestamp: May 06, 2021, 06:38:13 pm
content: Quote from: HKJ on May 06, 2021, 06:19:43 pmIt's bulky too. I don't think it's for desktop use, more for if you need to leave it logging data for a month.(but what would you do for a whole month without your Fluke 189?)

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 07:04:17 pm
content: Quote from: Fungus on May 06, 2021, 06:38:13 pmI had the 189 & 289 logging for more than a year nearly 24/7. I have lot of other meters I can use.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 08:02:51 pm
content: Quote from: HKJ on May 06, 2021, 07:04:17 pmHow long the batteries last during logging?Do you keep 189 and 289 logging the same DUT to be able to keep one working while replacing the batteries from the other?Maybe this can help you:

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 08:42:51 pm
content: Quote from: Trader on May 06, 2021, 08:02:51 pmI did never time it.Quote from: Trader on May 06, 2021, 08:02:51 pmThey where the first meters I used for the curves in my charger reviews:https://lygte-info.dk/info/roundCellChargerIndex%20UK.htmlMostly I restarting on a new logging session a couple of times each day and once in a while one failed because I did not notice that the batteries where about done.Quote from: Trader on May 06, 2021, 08:02:51 pmAs I wrote above, I have replace them with a better solution, now the meter are used on my test bench once in a while, but not much, I have way to many good multimeters to change between.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 06, 2021, 08:59:23 pm
content: If I have to do logging like you I would run either meter on AC power.

author: HKJ
author_rank: Super Contributor
timestamp: May 06, 2021, 09:21:05 pm
content: Quote from: BeBuLamar on May 06, 2021, 08:59:23 pmThat is also what I do now, but even with the 289 it was probably not more than once a week I had to replace batteries. I said 24/7 before, that was not really correct, each test is usually between 1 and 24 hours, but I cannot restart a new test while I am sleeping or on work, i.e. there where often some hours where the meters could turn off.

author: Trader
author_rank: Frequent Contributor
timestamp: May 06, 2021, 10:02:03 pm
content: Quote from: HKJ on May 06, 2021, 08:42:51 pmYour site is like a DMM Wikipedia. You should review the Fluke 189 and the Gossen for the posterity know how good they were.

author: HKJ
author_rank: Super Contributor
timestamp: May 07, 2021, 11:17:23 am
content: Quote from: Trader on May 06, 2021, 10:02:03 pmI do not want to review the 189 because it is out of production and has been for many years. I would sort of like to review the Energy, but I would like a new one to review, my Energy is from 2010.But I also have many other meters I would like to review and I have them, I only need to sit down and do the work. But for now my time is used on TestController and I am also looking on doing a comparison between a couple of high end multimeters (The Energy included).

author: Trader
author_rank: Frequent Contributor
timestamp: May 07, 2021, 04:14:01 pm
content: Quote from: HKJ on May 07, 2021, 11:17:23 amWhat's the problem? Your Energy is out of the specs? What happened?For me will be much more interesting Reviews of OLD and Very USED DMMs to see if they still keeping all the specs after 5, 10, 20, 30 years, and so on.Even an Aneng (or another Chinese medium quality device) usually works very well and inside the specs when Brand NEW.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 07, 2021, 04:19:55 pm
content: I agree on reviewing the 189. It was supposed to replace the 87 but Fluke decided that the 87 has a lot of following so they make the 87V. They replaced it with the 289 so the 189 production is kind of short so it would be interesting to review. I have the 189 since 2005 or so but I didn't use it much (a couple times a year?) so I am think I would try to use it more now and see how it is.

author: HKJ
author_rank: Super Contributor
timestamp: May 07, 2021, 04:53:54 pm
content: Quote from: Trader on May 07, 2021, 04:14:01 pmI do not believe so, it still matches my other meters on regular measurements.Quote from: Trader on May 07, 2021, 04:14:01 pmThat is another type of review/article, but it is a bit hard for me to do, because I do not remember when I bought a specific meter. With most of the reviewed meters I could use the date on the pictures as reference, but my Flukes and and Keysight/Agilent I have no precise idea about the date.Quote from: BeBuLamar on May 07, 2021, 04:19:55 pmI will rate it as a good meter and definitely recommend you use it more. It may not have as many measurements as the 289, but it is close and much better to use. Where the 289 really shines compared to the 189 is when doing stuff where multiple values on the display is a advantage (Mostly min/max), it can also show logged values as a curve.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 07, 2021, 07:16:24 pm
content: Yes I think I would try to use it more and no I don't use the 289 either. I use the 87V daily. May be I can clean the holster on the 87V without worrying about the strong solvent damaging the meter. The holster on the 189 and 289 is permanent and cleaning them risk having solvent on other parts of the meter.

author: David Hess
author_rank: Super Contributor
timestamp: May 07, 2021, 11:32:29 pm
content: Beckman had their Circuitmate series of handheld digital multimeters like the DM25L with capacitance and transistor hfe measurement in 1985 if not earlier. They even provided schematics. I have one somewhere.https://www.radiomuseum.org/r/bekman_ins_circuitmate_digital_multimeter_dm25l.htmlI consider capacitance, hfe, and frequency measurement to be almost completely useless on multimeters.

author: Fungus
author_rank: Super Contributor
timestamp: May 08, 2021, 10:08:03 am
content: Quote from: BeBuLamar on May 07, 2021, 04:19:55 pmThey're fast and they're 50,000 counts. Dual display can be nice.They also hold together really well at the outer limits of measurement (eg. AC with large DC offsets).There's a few too many positions on the selector switch IMHO but that's better than having to live with the wrong default setting for current (ie. AC instead of DC).

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 08, 2021, 11:32:36 am
content: Yeah although I almost never use the 87V to measure current but the fact that it defaults to AC current does bother me. I often use the current measurement function as a jumper.

author: Trader
author_rank: Frequent Contributor
timestamp: May 08, 2021, 01:35:26 pm
content: Quote from: BeBuLamar on May 08, 2021, 11:32:36 amLOL, I thought nobody does that.(1:19 min)

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 08, 2021, 01:59:25 pm
content: Great idea! I use the resistance and or diode check as voltage source. Now I learned something new.

author: Fungus
author_rank: Super Contributor
timestamp: May 08, 2021, 02:47:07 pm
content: Quote from: BeBuLamar on May 08, 2021, 01:59:25 pmUmmm.. it's a current source, not a voltage source.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 08, 2021, 02:50:35 pm
content: But I use it as a voltage source. The voltage output would depend on the input impedance of the device and the resistance range. I really need a voltage not current but just a low DC voltage not anything specific. What I do is to give a drive a voltage reference so it would run. A volt or two would be fine.

author: tautech
author_rank: Super Contributor
timestamp: May 09, 2021, 08:33:17 pm
content: Quote from: BeBuLamar on May 08, 2021, 02:50:35 pmYes but technically and correctly it's always a current source as Imax is limited and V available is related to I drawn.A small but definite distinction between what defines voltage and current sources.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 09, 2021, 08:43:27 pm
content: I know technically it's a current source as it supplies constant current in each range of measurement. But since I need a voltage I use it for the purpose of supplying a voltage to an inverter drive.

author: HKJ
author_rank: Super Contributor
timestamp: May 09, 2021, 08:51:00 pm
content: Quote from: BeBuLamar on May 09, 2021, 08:43:27 pmHandheld DMM's do not always use a current source for ohm measurement, often they do not. Read more here:https://lygte-info.dk/info/DMMDesign%20UK.html#Ohm