Hi Joe,
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Depending on where your lab is, it may worth checking around.
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But if you have not had yours done in 10-15 years, it may worth the effort if absolute accuracy is important to you, or if your DMMs are required to have current cal due to the type of work you do.
We're definitely off topic at this stage, but another reason the references being discussed are popular is because calibration is easy and inexpensive. Maybe $5 each way for shipping plus the calibration fee which is only charged after the 2nd year. So you don't need to ship out your precious.
When I had the HP's cal'ed I think it was around $150/ea. That was with the report. I assume the costs have gone up over the last 10 years.
I note you haven't quibbled about the chemical resistance, and missed off your list of PE uses "bottles for hydrofluoric acid", which I'll grant is a fringe case, so perhaps "fuel can" is more mainstream.
Hi,Are you saying that from your professional experience Brymens don't maintain calibration for long(er) periods of time?
Maybe my Brymen was a one-off, I was just surprised that a brand new factory calibrated multimeter had to be readjusted in a few areas during external calibration to get within its own specifications.
I don't know that at all from the Fluke models at work.
I've been employed there in the testfield since 2003 and am now the manager and jointly responsible for the measuring equipment used.
We have a database for this measuring equipment, where all calibrations since procurement are stored and of course also failures.
No Fluke has ever failed in these years.
Even an ancient Fluke 8060A (100khz TRMS !!!) has survived every calibration until its "natural" retirement.
This is a quality that Brymen must first prove over the decades.
That is why I personally do not let anything come on Fluke meters, it is simply professional quality that has its price and they are simply the industry standard.
Still, I like my BM869s, it has many good approaches and is hard to beat for the money.
And you can buy almost 3 BM869s for the nominal price of an 87V, so it wasn't hard for me to decide for personal use.QuoteWhere did you send it to be calibrated (if not in-house?). Thanks
Welectron offers a calibration service, not only for multimeters (you can choose) and either according to ISO or even DakkS.
They don't do it themselves, they then send it on to the lab.
https://www.welectron.com/Brymen-Multimeter-BM780-BM850s-BM860s-ISO-Calibration
I think this service is good, as a private person you usually can't get it so easily.
especially when you consider the 869 is more designed as a precision high count lab meter than a field test meter.
.. I need the calibration purely for DCV and DCmV.
I note you haven't quibbled about the chemical resistance, and missed off your list of PE uses "bottles for hydrofluoric acid", which I'll grant is a fringe case, so perhaps "fuel can" is more mainstream.You think the display glass on the fluke meter is made from PE?
I'm pretty sure it isn't. And I think that is also the part of the meter which will be the part most likely damaged and the part where damage is most visible.
If you take but a moment to actually think about it, the most likely parts of the meter to come into contact with such substances in a lab or workshop are the holster/back, range switch, and buttons.
If you take but a moment to actually think about it, the most likely parts of the meter to come into contact with such substances in a lab or workshop are the holster/back, range switch, and buttons.How so?
If your meter gets splashed with acid, it always miraculously misses the display?
Anyway, for PC to get affected by hydrochloric acid and PE not, that's usually a matter of days if not weeks. You'll have time enough to clean the housing of your meter.
Where the real danger lies is ingress. Both the Fluke 87V as the Brymen BM869s have some ingress protection by having internal seals around the jacks etc.
But by then the acid probably also already got into the jacks, eating away at the metal.
If getting splashed by acid is a real scenario for your DMM use, you should pick your meter based on whether or not it's IP67 rated with sealing plugs on the open jacks, not based on if the housing is made from PE or PC imho.
If you are interested in seeing how unstable my 121GW is compared with the other two, I made a short clip. Note, this is the 121GW that was never exposed to any of my testing. From what I remember, Dave was selling old stock which is what I received for the review so it is not the latest hardware. The firmware of the day was 2.02. They were playing a lot with the filters and maybe there is a version that is more stable but slower response??
Well than it's only very minor quantities and you'll have plenty time to clean the meter before the acid actually starts eating away at the plastic.
Maybe it would be more useful to test the ink from the lettering to test it's resistance to acids. I can't imagine that the ink will be more resistant to acid than the plastic, being either PC or PE, let alone eating away that the meter becomes unuseable but with the lettering still on it.
So if that's the only thing you worry about in choosing a meter and want a definitive answer, you'd have to wait until Joe Smith adapts his destructive tests to include various acids in various strength to the lettering, display, plastic and rubber boot.
Or do the testing yourself, as I doubt Fluke or Brymen do these tests with various acids in various strengths.
I works with acids and other corrosive anorganic chemicals all the time (I work in galvanics so highly concentrated acids (in very very large quantities) are no stranger to me), and generally plastics getting attacked by corrosive anorganic chemicals isn't a real problem. Not during the timespan we're talking about. If you're constructing a tank were acids sit in for years, sure, you'd want a tested HDPE or HDPP, but that's a completely different situation.
Besides, if you're handling acids in the concentrations and quantities we're talking about, that could actually start eating away at PC if left over time, you're not working with your standard nitrile doctors gloves anymore.
You'll be wearing really thick synthetic gloves that go up sleeves, and those are usually not the kind of gloves that make operating a multimeter very easy. Certainly not that easy that only the knob is touched and never the display. At least that's my experience when I work with electronic equipment and galvanic chemicals at the same time (and yes, that happens. Not the use of a dmm, but the use of specialized rectifiers and other specialized tools)
So I just don't really see the real world scenario that you have in your head.
The chance that the meter falls of a desk or cabinet is much more likely, so impact resistance of the plastic the housing is made of is way more important. So I guess that is why manufacturers test that and give a spec on that, and not it's chemical compatibility to acids.
Besides if these situations occur in a lab, anorganic chemicals that are that potent that they affect plastics, will only be used under a fume hood. If some worker walks away from that still with his gloves on drenched in the stuff to a bench where a dmm is set up, he'll be denying a lot of H&S regulations, risking his co workers way more than a potential DMM. And if the DMM is set up in the fume hood, it becomes a specialized piece of equipment that probably will be tested in advance if it is suitable for that space and there'd be a protocol how to use it.
The most likely situation of a DMM being exposed to a fairly strong acid is I think in a garage, where some amateur is tinkering away with battery acid (37% sulfuric acid) and is getting it over his multimeter. Althoug I don't think it'll attack the PC plastic unless it's a fair amount and left to dry in for days. I imagine the lettering being gone long before that.
Can't fix stupid, can you?
However, this thread was really about the BM789 and it only seems fitting that I show mine. Again, this meter (along with all of my BM78x meters) was provided by Brymen during the development of the meter. This particular one was after the final changes. I have never changed anything with the hardware or touched the alignment.
However, this thread was really about the BM789 and it only seems fitting that I show mine. Again, this meter (along with all of my BM78x meters) was provided by Brymen during the development of the meter. This particular one was after the final changes. I have never changed anything with the hardware or touched the alignment.Yes I saw your video and how fast they fixed that bug you found in the firmware. Very interesting to see them having such a pro-active approach to improve their products.
I'm sure the 78x series will hold up in time just as well as the 86x series and 23x/25x series have. Very well thought out designs and quality materials. On par with Fluke, only for a fraction of the price.
Especially since early this year, Fluke has increased their prices quite a bit here in europe. A BM869S costs €209 (incl tax) with the silicone leads, or more on topic, the BM789 costs €192 with the silicone leads, whereas the Fluke 87V now costs €650 (incl tax) with the crappy pvc leads...
I have a 121gw serial number 001307 with firmware 2.02 and when reading 500 millivolts from a PDVS2 mini it is perfectly stable and reads 500.00 millivolts exactly.
Someone else with a 121GW would need to look at theirs. Maybe the newer ones are more stable.