What's the cheapest 0.02% accuracy handheld meter - Page 1
Forum section: electronics / testgear

author: miegapele
author_rank: Contributor
timestamp: July 12, 2023, 06:58:47 pm
content: For the last five years I was using RM303 (basically smaller AN870) as my primary multimeter. It's specified as 0.05% DC accuracy and is very nice multimeter. Now I wanted more accuracy and started looking for 0.02%/0.03% accuracy multimeter.However, it seems there is not much cheap Chinese stuff available. I found HP-770D, (40000 count, but spec only 0.1%), there is also UT71C, but it's very old and around 200 EUR. The cheapest I found seems to be BM785/BM786 for around 150EUR.What's the cheapest handheld DMM with 0.02% DC accuracy currently on the market?

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 12, 2023, 07:04:35 pm
content: This just occurred to me, for handheld DMM we often just take manufacturer's spec at face value don't we? Save for select few high end with known and well characterized reference and ADC.

author: miegapele
author_rank: Contributor
timestamp: July 12, 2023, 07:14:22 pm
content: You don't need super high end reference to get 0.02% accuracy. Flukes are known for being accurate to the last count even if decades old, I expect the same to be true for other reputable brands. Dave did a review of that Chinese special years ago, and it was in spec. Given how much he hates Chinese wonder multimeters, lack of any follow up showing that Chinese DMM drifted 0.000000001% out of spec, can be taken as confirmation that would be in spec too

author: Martin72
author_rank: Super Contributor
timestamp: July 12, 2023, 08:06:36 pm
content: https://www.welectron.com/Brymen-BM859s-Multimeter_1199 incl VAT...I find this very cheap......and damn good looking..

author: CosteC
author_rank: Regular Contributor
timestamp: July 12, 2023, 08:25:36 pm
content: APPA 506SANWA PC7000Both around 225 euro, both more modern than BM859S.BM785 is surprisingly cheap indeed. Wonder why.

author: Fungus
author_rank: Super Contributor
timestamp: July 12, 2023, 08:29:18 pm
content: Quote from: Martin72 on July 12, 2023, 08:06:36 pmAnd probably much better than 0.02% in practice.(in fact the cheaper BM857s is probably better than 0.02% - mine certainly is)

author: Martin72
author_rank: Super Contributor
timestamp: July 12, 2023, 08:32:48 pm
content: Quote

author: slavoy
author_rank: Regular Contributor
timestamp: July 12, 2023, 09:06:36 pm
content: I think also of Brymen BM859s (0.02%) or 857s (0.03%). Probably not the cheapest in the world, but generally very good multimeters. Will last decades.

author: RFDx
author_rank: Regular Contributor
timestamp: July 12, 2023, 10:20:20 pm
content: Quote from: CosteC on July 12, 2023, 08:25:36 pmSanwa PC7000:JP: 248€ (eBay)US: 389$ (Sanwa US)CN: 435€ (Ali)DE: 745€ (Conrad)Looks like purely arbitrary pricing.Brymen 789 (0.03%, 60000 counts)Brymen 869 (0.02%, 500000 counts)Pricerange 190...220€ (incl. VAT). The 789 has a more modern appearance.

author: DaJMasta
author_rank: Super Contributor
timestamp: July 12, 2023, 10:27:16 pm
content: It's 0.03% but 500,000 count - the Brymen 867s that's been mentioned a couple of times. Currently 160 EUR after tax from Brymen.eu or Welectron.Pretty cheap for the performance and features, I've had mine for a good bit and other than occasionally having the display go blank when first setting a range (the switch now has a tiny bit of play that means the initial position isn't always directly on the contacts), mine has been great.

author: bdunham7
author_rank: Super Contributor
timestamp: July 12, 2023, 10:42:03 pm
content: Quote from: miegapele on July 12, 2023, 06:58:47 pmThe devil is in the details. A stated 0.02% 'basic DC accuracy' is not a complete spec. You need to look at the total specification for each range, typically expressed as (% of reading + counts) or (ppm of readin + ppm of range) or something like that. So on your RM303, according to the specs if you are measuring 1V, the specified error is 0.05% of reading (5 counts) plus 3 counts for a total of 8 counts. And in reality, it may or may not meet those specs, IMO that figure seems a bit aspirational, especially since it is claimed for all ranges. The Fluke 289, for example, is 0.05% + 20 counts in the lowest mVDC range, whereas your RM303 claims the same accuracy in the 20mVDC range as it does for all the others--0.05% +3 counts.

author: J-R
author_rank: Super Contributor
timestamp: July 13, 2023, 12:27:30 am
content: 500,000 count mode is only available for DCV and DCmV and I don't see where the accuracy specifications are defined in that case.

author: David Hess
author_rank: Super Contributor
timestamp: July 13, 2023, 01:23:18 am
content: When looking for higher accuracy, I also expect a fixed 10 megohm input resistance or a gigohm input, which is going to mean a bench meter.

author: J-R
author_rank: Super Contributor
timestamp: July 13, 2023, 03:13:13 am
content: Some thoughts on the accuracy specifications. It is true that some test equipment greatly exceeds published accuracy specifications. I could imagine some reasons for this, such as the manufacturer wanting to maintain the accuracy over a wide range of operating conditions or life of the product, extra margin for internal component variations from suppliers, shared manufacturing lines, etc.However, the main issue is HOW do you leverage that accuracy performance? Some of my methods include obtaining calibration plus data, having a collection of references, and comparing against other test equipment where I have calibration data already available. Without this information, you are going to be somewhat limited to using the published numbers and the reputation of the manufacturer.It's a bit tricky to leverage the 500,000 count mode of the Brymen DMMs, so if you are planning to bank on that I would suggest at least a high-quality 5V reference to check it against (or even calibrate it if desired). At lower points in the ranges it can be particularly trust-worthy, so for example 1V. I calibrated my BM869s a year or so ago and it's still basically perfect in this case. Although it's more of an intellectual exercise. Just get a decent bench DMM if you're bumping into this requirement level.

author: bdunham7
author_rank: Super Contributor
timestamp: July 13, 2023, 03:40:46 am
content: Quote from: J-R on July 13, 2023, 03:13:13 amIf you are a hobbyist that doesn't need to prove anything to anyone, then your imagination is the limit. For example, you can use calibration certificates in reverse to imagine you know what a meter actually reads to 10X its spec if you like. Or dial them in to the last count and ignore the tempco that you can't control for.If you need certifiable results, then I think the whole point is that you don't leverage the difference between specified and actual performance to achieve a tighter spec, but rather to get a greatly increased probability--hopfully a near certainty--of meeting the spec. The two parameters (reading uncertainty vs the probability of being in spec) are intertwined and inseparable.

author: CosteC
author_rank: Regular Contributor
timestamp: July 13, 2023, 06:24:10 am
content: Quote from: RFDx on July 12, 2023, 10:20:20 pmLate capitalismPrice has nothing to do with cost of manufacturing or development.APPA is also available rebranded in many places. BENNING IT 101, RS PRO IDM505 is probably APPA 505. Rebrands are ususally far more expensive howeverhttps://ndn.com.pl/en/digital-multimeters/1972-digital-multimeter-pc7000-sanwa-50000-acdc-acc-003.htmlhttps://ndn.com.pl/en/glowna/4164-digital-multimeter-appa-506b-acdc-003-truerms-bluetooth.html?search_query=506&results=11https://ndn.com.pl/en/digital-multimeters/3930-multimetr-cyfrowy-appa-506-acdc-dokl-003-truerms.html?search_query=506&results=11

author: J-R
author_rank: Super Contributor
timestamp: July 13, 2023, 06:37:28 am
content: No matter how you look at it, published accuracy specifications are far more imaginary than a specific instrument's calibration data.I see a TE industry where a lot of the accepted product specifications seem to originate from the marketing department. And that is probably fine, because at the end of the day you need to make a product that will sell. But on the flip side we have plenty of products that can be hacked to higher performing models and of course as I mentioned, products that exceed their published specs by a significant margin.I specifically did not mention calibration certificates, only calibration data. The data is literal proof in print that a "meter actually reads to 10X its spec". Also, it has the temperature at which the calibration data was taken, so you can match that environment.In all areas of life we have hobbyists who push things to the limits, both dangerous and not. Industry, especially for paying customers, takes a much more conservative approach and has to account for a TON of variability, with regard to how standards are enforced, human nature, manufacturing variability, the list goes on...So with that in mind, there is nothing wrong with a hobbyist discovering that their test equipment performs far better than expected and then capitalizing on that fact. On the flip side, it is definitely wrong to blindly trust a published spec and/or calibration certificates and that is why many industries have proving requirements as well.

author: CosteC
author_rank: Regular Contributor
timestamp: July 13, 2023, 06:53:13 am
content: I am rather on conservative end when it comes to datasheet performance. While my old APPA 72 has "only 0.5%" is it far more stable than cheap chinese no-brand multimeter which drifts with battery depleting. Long term stability for hobbyst is not super important if meter can be validated often. In industry nobody will do it - too much time, just buy better one if needed.Most magic question for me is what hobbyst application calls for 0.03% accuracy and how to validate this accuracy in hobby environment? Professionally it would require well better instrument, starting from 0.01% but 6 1/2 digit DMM with starting from 0.0050% would be best.What measurements require 0.03% DCV really? I used to measure small temperature differences for industrial processes, this was one case.Other case seems to be measurements of small voltages, but there amplifiers come handy, however topic is tricky due to noise.I appriciate AN870 declared accuracy, yet I do not trust it too much in long term...

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2023, 06:55:09 am
content: Quote from: RFDx on July 12, 2023, 10:20:20 pmIt's also a lot bigger and has a lot more distractions than the "industrial" BM857s/BM859s.If you spend all day long looking at voltage/frequency simultaneously then go for dual display, no wukkas.If you only do that rarely then why have a complicated display? Pressing a button to see Hz isn't too terrible and you can always add a second (or third) meter to see more values in a long session. :-)Same goes for the selector switch. Do you really want multiple functions on every range when you hardly ever use most of them? The BM857s has separate switch positions for just about everything, only ohms/continuity is shared. This meter seems like the sweet spot to me.My $0.02...

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2023, 06:58:21 am
content: Quote from: CosteC on July 13, 2023, 06:53:13 amWhy not? There's not much inside one to go wrong.It might have a worse tempco than a more expensive meter, or whatever, but I see no reason why it would go out of spec just because of the passage of time.

author: slavoy
author_rank: Regular Contributor
timestamp: July 13, 2023, 07:29:25 am
content: Quote from: miegapele on July 12, 2023, 06:58:47 pmRegarding the Aneng AN870, I compared my unit to the Siglent SDM3065X as a reference, and it performed according to specifications, even better (@DCV/mV range). The basic accuracy of 0.02% for a handheld multimeter is quite high and approaches laboratory-grade equipment.If you want to maintain such accuracy, you not only need to follow proper measurement practices but also verify the DMM with a higher-grade instrument. Otherwise, that precision will be compromised, and the measurements will simply not be meaningful. I'm not sure why such high accuracy is necessary for you, but it's not just about buying the right multimeter.Personally I don't see the practicality of buying a higher-grade DMM than this Aneng in terms of accuracy (only). I'm curious about what you actually need such accuracy for

author: CosteC
author_rank: Regular Contributor
timestamp: July 13, 2023, 08:13:38 am
content: Quote from: Fungus on July 13, 2023, 06:58:21 amLot of stuff already went wrong1) Manufacturer does not provide anything remotly similar to proper specifications. What is long term drift? Nobody knows.2) What manufacturer?https://anengmultimeter.com/Sells clothing... Aliexpress shop?3) Reference is only one thing among many responsible for accuracy. None is particularly recognisable or look stableI do not say it does not work. It works. But will it work next year? Probably. Will it permanently shift after ESD zap or long term application of high voltage? Probably. Is it resistant to radio interference? Rather not.Is it great for hobbyst? YES.

author: armandine2
author_rank: Frequent Contributor
timestamp: July 13, 2023, 08:14:41 am
content: Quote from: slavoy on July 13, 2023, 07:29:25 amThis reaction comes up on many threads - which always reminds me of Zipf's Least Effort book - bedtime readinghttps://cseweb.ucsd.edu//~rik/foa/l2h/foa-3-2-1-1.htmlIn a mature society in which a variety of jobs and tools have existed for some time, a ``reciprocal economy'' forms. That is, there is a set of tools good for doing certain jobs, and there is a set of jobs requiring certain tools. The Principle of Least Effort asserts that a person attempting to apply a tool to a job does so in order to minimize the probable effort in using that tool for that particular job.

author: AVGresponding
author_rank: Super Contributor
timestamp: July 13, 2023, 08:16:21 am
content: FWIW, my own philosophy is not to buy the cheapest I can find, but to buy the best I can afford...

author: MiroS
author_rank: Regular Contributor
timestamp: July 13, 2023, 08:19:44 am
content: Quote from: slavoy on July 13, 2023, 07:29:25 am0,05%+3 not 0.02%, the question was for 0,02% not for something worest.

author: MiroS
author_rank: Regular Contributor
timestamp: July 13, 2023, 08:23:53 am
content: Quote from: CosteC on July 13, 2023, 08:13:38 amMy AN870 died by laying on the shel.

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2023, 08:24:01 am
content: Quote from: AVGresponding on July 13, 2023, 08:16:21 amBut then you have to define "best" - an impossible task!That path doesn't lead to happiness.

author: AVGresponding
author_rank: Super Contributor
timestamp: July 13, 2023, 11:16:15 am
content: Quote from: Fungus on July 13, 2023, 08:24:01 amNot at all, it merely leads to a large collection of TE!In context, it means the best quality (in terms of performance, construction and warranty) in a device that meets the task criteria.

author: Fungus
author_rank: Super Contributor
timestamp: July 13, 2023, 11:24:29 am
content: Quote from: AVGresponding on July 13, 2023, 11:16:15 amSo now you have to define "the task".

author: bdunham7
author_rank: Super Contributor
timestamp: July 13, 2023, 12:59:55 pm
content: Quote from: J-R on July 13, 2023, 06:37:28 amThe data is proof that the meterdidread certain, specific values on that day, under the specific conditions stated and to within the uncertainty of the test stimulus, provided that is provided and traceable.That calibration data, combined with the manufacturers stated specifications and calibration interval, gives you a certain level of assurance (perhaps 95% or 99%) that the same meter will readallvalues within its range of measurement to within the stated uncertainties under all conditions listed (the typical +/-5C being most important, but others like RH, EF and altitude may matter some too) for the duration of the calibration interval.Those are two very different statements. I can take a Richmeter or Aneng and connect it to a standard or calibrator and verify that it reads 10.000V exactly for a 10V reference. I can even write down the temperature and make a little chart. But if I take it for a 50-mile drive out in the mountains and while testing some equipment (indoors, room temperature) I take a measurement of 7.492V, what is my confidence level that this reading is accurate to within a certain amount, say 6 counts? The answer is that while there is a good chance it might be right, you don't really know since the manufacturer 'specs' don't give you any idea.

author: miegapele
author_rank: Contributor
timestamp: July 13, 2023, 03:31:56 pm
content: Quote from: bdunham7 on July 12, 2023, 10:42:03 pmI'm very well aware of that, but that is how data is usually presented everywhere, including Fluke websiteQuote from: CosteC on July 13, 2023, 06:53:13 amNo reasonable multimeter with 0.0X% spec will drift with battery voltage. Only the king of multimeters, that is DT830 is allowed to do that.Quote from: CosteC on July 13, 2023, 06:53:13 amSimple, It's called "I want". Actually 99% of the forum discussions here is based on precisely that application.Quote from: CosteC on July 13, 2023, 06:53:13 amAny references to that? Other posted provided evidence that it's fine.Quote from: CosteC on July 13, 2023, 08:13:38 amManufacturer is irrelevant, unless you buy your Fluke for status, that is.Quote from: CosteC on July 13, 2023, 08:13:38 amReference is probably most important thing still, look at any teardown Dave does, reference always gets lots of attention. And also how do you determined that its not stable?Quote from: CosteC on July 13, 2023, 08:13:38 amWhy this matters? I'm not sure that's common design criteria for multimers.Quote from: CosteC on July 13, 2023, 08:13:38 amWhats long term drift on Fluke? I doubt anybody knows either.Quote from: bdunham7 on July 13, 2023, 12:59:55 pmWhat kind of guarantee Fluke provides here? Do they spec their multimeter for altitude?

author: miegapele
author_rank: Contributor
timestamp: July 13, 2023, 03:33:35 pm
content: Thank you all foe great advice.I guess I need to start saving money to buy Brymen for Christmas

author: mwb1100
author_rank: Frequent Contributor
timestamp: July 13, 2023, 03:54:16 pm
content: So the conclusions of this thread to get an inexpensive multimeter with high basic accuracy (0.05% or better) as specified/claimed by the manufacturer seem to boil down to:1. the best you can do for basic accuracy in a 50-ish EUR/USD meter is 0.05%2. if you want 0.02 - 0.03% basic accuracy, you will need to move to a 150-200-ish EUR/USD price range and likely a Brymen BM78x, BM85x, or BM86x(of course this is a simplistic analysis that ignores how accurate the manufacturers claims are, the stability of the meter's accuracy, the number of counts involved in the accuracy, etc)

author: bdunham7
author_rank: Super Contributor
timestamp: July 13, 2023, 04:18:53 pm
content: Quote from: miegapele on July 13, 2023, 03:31:56 pmThey do spec for altitude and a lot of other things. In this case for a 289, as long as the indoor temp is between 18 and 28C, the RH is less than 90% and the alititude is under 3000M, they guarantee that a voltage of 7.492 will result in a reading between 7.488 and 7.496V, or conversely that a reading of 7.492 indicates an actual voltage from 7.488 to 7.496.But this meter (the Fluke 289) would not meet your specified goal of having an 'advertised accuracy' of 0.02%. You can buy a Brymen 869S which does have an advertised "DC basic accuracy" of 0.02%, but alas on the 50V range it is 0.03% + 2 counts and is only specified to 2000M altitude and 80%RH. A strong contender, but not the winner.QuoteOf course the reference is critical, but it is not the hardest or most expensive component to optimize. The thing that distinguishes the excellent from the average is the ability to produce (or source) high-quality resistors.

author: AVGresponding
author_rank: Super Contributor
timestamp: July 13, 2023, 05:09:46 pm
content: Quote from: Fungus on July 13, 2023, 11:24:29 amThat's the job of whoever is buying the meter. I can't define it for someone else.

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 13, 2023, 05:17:59 pm
content: I have a good number of meters and none has 0.02% basic accuracy specs. The best I have are the Fluke 287 and 289 which only get 0.025%. The 189 is the same. The 87V is only 0.05%. And none is cheap so I don't know how to get 0.02% cheap.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2023, 05:31:58 am
content: Quote from: BeBuLamar on July 13, 2023, 05:17:59 pmGet one of these instead:They're a fraction of the price of any of those others you listed.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2023, 05:34:52 am
content: Quote from: AVGresponding on July 13, 2023, 05:09:46 pmAaaaand ... we've gone full circle.https://www.eevblog.com/forum/testgear/whats-the-cheapest-0-02-accuracy-handheld-meter/msg4958980/#msg4958980

author: AVGresponding
author_rank: Super Contributor
timestamp: July 14, 2023, 08:43:57 am
content: Quote from: Fungus on July 14, 2023, 05:34:52 amThat's how these threadsalwaysgo...Quote from: Fungus on July 14, 2023, 05:31:58 amI would dispute the claim of Brymen meters being "cheap". I would describe them as "less expensive". Their reputation for random MCU failures is troubling; it's not going to be leading edge silicon fab technology, so why is it unreliable? Failure rates on something like that should be so low that you never hear about it.Equally troubling is the apparent cost-cutting by Fluke on the plastics they use for their connectors in recent years; is it an in house or third party supplier issue? I don't know, but they need to sort it.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2023, 08:59:02 am
content: Quote from: AVGresponding on July 14, 2023, 08:43:57 am"Reputation"? I don't know where you're getting that from.

author: Fungus
author_rank: Super Contributor
timestamp: July 14, 2023, 09:31:11 am
content: Quote from: Fungus on July 14, 2023, 05:31:58 amI would dispute the claim of Brymen meters being "cheap". I would describe them as "less expensive".Yes, but GP seemed to be saying that if none of his expensive Flukes could do it then they must not exist."Cheap" is a relative term. Brymens are definitely cheap compared to Flukes.

author: joeqsmith
author_rank: Super Contributor
timestamp: July 14, 2023, 11:48:42 am
content: The Metrawatt M248B (rebranded Prime) is 0.02%. About $900. Download the manual for details. The meter has a lot of issues that I doubt were ever addressed and if you're in the USA, good luck dealing with them.If I need that accuracy, I am using my bench meters.

author: bdunham7
author_rank: Super Contributor
timestamp: July 14, 2023, 02:14:00 pm
content: Quote from: Fungus on July 14, 2023, 05:31:58 amQuoteComparing small differences in basic specs between different brands without getting into all the details and conditions is not all that helpful, or at least not very precise. However, I did notice that your BM859S seems to have significantly better DC specs (look at the higher ranges) than the BM869S. Hmmmm.

author: CosteC
author_rank: Regular Contributor
timestamp: July 14, 2023, 02:43:01 pm
content: I am puzzled by whole this discussion focusing purely on DCV accuracy. Simplest of all. Long time ago I needed to measure AC current of 400 A 50 Hz with better than 0.5% accuracy. Seems not a lot, but I am pretty sure none of instruments above cannot do it, despite 0.02% "astonishing" accuracy...What I wanted to say: DCV accuracy is not all that matters.

author: alm
author_rank: Super Contributor
timestamp: July 14, 2023, 02:55:50 pm
content: Quote from: CosteC on July 14, 2023, 02:43:01 pmTrue. While for good meters usually the more accurate meters have improved accuracy across the board, you should always check the specification for the specific functions, ranges and in the case of AC frequency that are important for you rather than relying on banner basic accuracy specs.

author: miegapele
author_rank: Contributor
timestamp: July 14, 2023, 03:29:02 pm
content: Quote from: CosteC on July 14, 2023, 02:43:01 pmLong time ago I also needed to measure dog weight, and none of the instruments here can do it, bummer. This is way of topic, but as far as I know, such currents usually are measured with external shunts, and any multimeter mentioned here would work.

author: CosteC
author_rank: Regular Contributor
timestamp: July 14, 2023, 03:42:01 pm
content: Quote from: miegapele on July 14, 2023, 03:29:02 pmWould it? Shunts rarely provide more than 100 mV. AN870 has 0.3%+3d on 1,9999 VAC range. This means 0.6% error + shunt error, 0.2% for good shunt.

author: bdunham7
author_rank: Super Contributor
timestamp: July 14, 2023, 04:07:20 pm
content: Quote from: miegapele on July 14, 2023, 03:29:02 pmCosteCmade a good point but just didn't choose the best example to illustrate the issue.The Brymen 869S is touted as the cheaper (by 3-4X) alternative to the Fluke 289. So imagine you need to measure 550VDC as precisely as possible--that's not "dog weight", it is something both meters are rated to do. The 869S is a "0.02%" meter, better than the "0.025%" 289, right? But the actual specified uncertainty for the Brymen for this measurement will be more than a volt, whereas for the 289 it will be about a third of that.

author: miegapele
author_rank: Contributor
timestamp: July 14, 2023, 04:21:39 pm
content: Quote from: bdunham7 on July 14, 2023, 04:07:20 pmI disagree here, It's just cherry picking points for distraction. 400A is definitely not common. You can probably find some random spec where 0.03% Brymen is better than that 289. Does that mean anything? No.

author: rfclown
author_rank: Frequent Contributor
timestamp: July 14, 2023, 04:23:44 pm
content: Quote from: Fungus on July 13, 2023, 06:58:21 amI assume you haven't owned a ANxxx meter. I have a couple. On mine the resistance readings vary wildly with battery contact resistance. To me, the specs mean nothing; they are cheap meters worth what you pay for. If I want a measurement I can trust, I'll use one of my Flukes or HPs. I personally don't have a need for a 0.02% accurate meter, but I do have a need for meters that give me reliable readings... which my ANxxx meters don't do.

author: CosteC
author_rank: Regular Contributor
timestamp: July 14, 2023, 04:30:20 pm
content: Quote from: bdunham7 on July 14, 2023, 04:07:20 pmYou are welcomeLets examine something better than ANENG. Or at least seemingly better.Quote from: bdunham7 on July 14, 2023, 04:07:20 pmIt is 0.02% meter, Brymen style: at two ranges 0.2%, worse for other 3 ranges: 0.3%, 0.4% and 0.15% for 500-1000 VDC.BM869S has 0.3% +20d on 500.00 mV range. For case mentioned this means 0.5 mV error - 0.5%. Surprisingly it is BEST AC range. 500 VAC range has 0.5% + 40d. At best 45-300 Hz case.Brymen is 0.1% better than Aneng AN870 in this scenario (quite realistic as sub 1 V AC measurements are not so rare)

author: bdunham7
author_rank: Super Contributor
timestamp: July 14, 2023, 04:44:37 pm
content: Quote from: miegapele on July 14, 2023, 04:21:39 pmChoosing the meter based on the headline spec doesn't tell you which one is more accurate for a specific case. And if that doesn't mean anything, then what's the point of the whole discussion?

author: Aldo22
author_rank: Super Contributor
timestamp: July 14, 2023, 05:10:40 pm
content: If you work in a restaurant kitchen from freezer to pizza oven, you better use an AN8008.It gives more stable readings over the temperature range than a BM869s says joe smith.https://youtu.be/TSGLA9heboY?t=1768

author: alm
author_rank: Super Contributor
timestamp: July 14, 2023, 10:02:23 pm
content: Quote from: miegapele on July 14, 2023, 04:21:39 pmIf you need the meter for a particular task, like adjusting a trimmer so the voltage between two test points reads 9 V +/- 0.05% with 99% confidence, then yes, it makes a difference if a meter is +/- 0.02% or +/- 0.07% in that range. But another person might me measuring 900V all day. This means the question which of the meters offers the best accuracy might have a different answer for those two people.

author: miegapele
author_rank: Contributor
timestamp: July 15, 2023, 04:41:41 am
content: Quote from: alm on July 14, 2023, 10:02:23 pmYes, but that's precisely what's cherry picking and distracting is. You can quote millions different scenarios, and some meters will be better suited than others, but I wrote what I need, and that is "cheapest 0.02%" multimeter, so I can sleep calm knowing my AA battery is 1.456V and not some lousy 1.455V. I thought maybe I missed something cheap, but unfortunately such thing does not exist. I guess market is too smallObviously it's SOP in here for some to bring FLUKEs every time, although topic clearly states "cheapest", but I guess that's nice for entertainment .

author: bdunham7
author_rank: Super Contributor
timestamp: July 15, 2023, 05:06:54 am
content: Quote from: miegapele on July 15, 2023, 04:41:41 amOK, the 10,000 count Fairchild 7000A is specified for 0.01% + 1 count. I got mine for $100, although you might struggle to find the same deal these days. And it needed a bit of work too.

author: miegapele
author_rank: Contributor
timestamp: July 15, 2023, 07:31:52 am
content: Quote from: bdunham7 on July 15, 2023, 05:06:54 amThank you, that's actually way more relevant than all these "but what if you want to measure primary current of nuclear power station transformer" comments.

author: mwb1100
author_rank: Frequent Contributor
timestamp: July 15, 2023, 02:50:21 pm
content: Quote from: miegapele on July 15, 2023, 04:41:41 amOh my God - there's someone else with that problem?

author: bdunham7
author_rank: Super Contributor
timestamp: July 15, 2023, 04:14:07 pm
content: Quote from: mwb1100 on July 15, 2023, 02:50:21 pmI would refer you both to this thread:https://www.eevblog.com/forum/beginners/battery-voltage-reduces-the-longer-it-is-being-mm-voltage-tested/msg4930432/#msg4930432

author: miegapele
author_rank: Contributor
timestamp: July 15, 2023, 08:17:23 pm
content: With 10M input resistance and 4 digits you need to wait quite a long time to see a drop. But with 6 or 7 digit DMM it's quite easily visible. Dave showed it in one of his videos.

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 02:47:22 am
content: Quote from: miegapele on July 15, 2023, 08:17:23 pmA handheld with a 500,000 count mode shows it quite well...

author: bdunham7
author_rank: Super Contributor
timestamp: July 16, 2023, 03:42:27 am
content: Quote from: Fungus on July 16, 2023, 02:47:22 amI've lost the plot--what is "it"?

author: Veteran68
author_rank: Frequent Contributor
timestamp: July 16, 2023, 03:44:21 am
content: Quote from: bdunham7 on July 16, 2023, 03:42:27 amSounds like they're talking about watching a battery's voltage being drained by the measuring meter.

author: bdunham7
author_rank: Super Contributor
timestamp: July 16, 2023, 04:30:32 am
content: Quote from: Veteran68 on July 16, 2023, 03:44:21 amHmmm, do you mean like this?https://youtu.be/g8wDRsnLrEc

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 05:12:04 am
content: Quote from: bdunham7 on July 16, 2023, 04:30:32 amNope. definitely not like that. That guy's fingers are probably draining the battery faster than the meter.

author: bdunham7
author_rank: Super Contributor
timestamp: July 16, 2023, 05:15:14 am
content: Quote from: Fungus on July 16, 2023, 05:12:04 amI have really dry hands so that generally isn't a problem. Not that it matters in this case--look more closely at the numbers.

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 05:23:52 am
content: Quote from: bdunham7 on July 16, 2023, 05:15:14 amYour hand is conducting electricityandwarming up the battery?

author: bdunham7
author_rank: Super Contributor
timestamp: July 16, 2023, 05:43:26 am
content: Quote from: Fungus on July 16, 2023, 05:23:52 amNo, neither really. Just to be sure I measured my fingers in the same positions I was holding the battery and with the same probes. With approximately the same pressure used to hold the battery, I'm 106M. With a lot more pressure, 26M. And the battery was cooling down, it had been in a warmer spot.The whole theme of this thread (to me) is making assumptions without examining them and even resisting challenges to them. The original example was "I want a more accurate (cheap) multimeter and I'm going to judge that solely by the advertised basic DC accuracy headline spec". Now we have drifting battery voltages and assumptions about why that happens.You see a battery connected to a many-digit multimeter with the LSD slowly counting down. You assume that the reason for that is that the ~150nA is flowing in a 1.5V/10M circuit is drawing down the battery. You see someone doing the same thing but holding the battery in their hand and the voltage is going up, you assume the reason is that the battery temperature is increasing. It turns out that there might be other reasons for these behaviors and unless you somehow quantify the effects that you attribute the changes to, you can't reliably assign causes to your observations.With an AA battery, unless you can accurately (very accurately) measure temperature and also know how the battery behaves, thermal effects will probably outweigh all those other things by quite a bit. In this case, at near room temperatures, the battery voltage goesdownas the battery warms up and there is no discernable difference between the 10M and Hi-Z modes on the meter. If I hold the battery differently so as not to 'short' it with my 100M fingers the voltage changes (drops)morequickly, presumably because more of my hand is in contact with it and thus it warms faster. This is not what I expected when I tried this out just a bit ago.Things are never as simple as we want them to be.

author: mwb1100
author_rank: Frequent Contributor
timestamp: July 16, 2023, 07:19:46 am
content: Speaking for myself, my comment was just a joke about obsessing over a AA battery measuring 1.456V vs 1.455V. Ie., that I sometimes obsess over absurd things.

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 07:31:27 am
content: Quote from: mwb1100 on July 16, 2023, 07:19:46 amWe know :-)

author: Aldo22
author_rank: Super Contributor
timestamp: July 16, 2023, 08:20:23 am
content: Mycheapest DMMhas a battery test mode.Isn't it better anyway to measure the batteries under load?Quote

author: miegapele
author_rank: Contributor
timestamp: July 16, 2023, 09:29:12 am
content: Quote from: bdunham7 on July 16, 2023, 04:30:32 amunlisted? You should be posting this to TikTok with some free energy clickbait title

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 10:54:33 am
content: Quote from: miegapele on July 16, 2023, 09:29:12 amElectroman charging up a battery with his fingers.

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 16, 2023, 01:46:00 pm
content: Quote from: mwb1100 on July 16, 2023, 07:19:46 amBut if I measure an AA battery with no load and it reads either 1.456 or 1.455V I would toss it.

author: Fungus
author_rank: Super Contributor
timestamp: July 16, 2023, 02:40:51 pm
content: Quote from: BeBuLamar on July 16, 2023, 01:46:00 pmI draw the line at 1.450 myself

author: mwb1100
author_rank: Frequent Contributor
timestamp: July 16, 2023, 06:48:27 pm
content: Quote from: Fungus on July 16, 2023, 07:31:27 amThe thread turned to temperature and skin conductivity affecting the 5th or 6th least significant digit of AA voltage right after...

author: bdunham7
author_rank: Super Contributor
timestamp: July 16, 2023, 07:06:48 pm
content: Quote from: Fungus on July 16, 2023, 02:40:51 pmYou'd be better off bouncing them...

author: alm
author_rank: Super Contributor
timestamp: July 16, 2023, 07:15:27 pm
content: Quote from: bdunham7 on July 16, 2023, 07:06:48 pmOnly if you use a ruler with "accuracy: 0.02%" stamped on it to measure the bounce height.