EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: loptosh23 on December 09, 2018, 03:34:23 am
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Hello,
I need a new meter and after doing my research I am trying to decide between Brymen BT867S and BT857S.
Searching did tell me stuff about one of them or the other, but could somebody help me see some important differences between them?
Because to me they seem kind of identical. Same accuracy, same count, same digits, same price... only the display size is different, but is that it?
and confusingly, the one with bigger display is cheaper...
I feel like I must be missing something, because why would they keep producing both?
I would understand if one was new model, replacing an older one, but if both are available for so long, that I even failed to find out which one of them is older...
My application would be mainly low voltage audio circuits. My current meter is OK for most things, but it fails to give me accurate mV range readings when I need them. Also the port for connecting to PC would be nice when I'm measuring batch of parts to find matched pairs.
867:
+ Bigger display, so more things visible at the same time
+ Infra to USB cable / software kit in stock right now
857:
+ Aesthetics, I like the 857 simple rectangular shape.
- Less convenient Infra to serial to USB cable and it also isn't in stock right now
So 867 seems like a clear winner and would grab it, if I wouldn't be confused by would 857 even exist, if it is worse and 3 EUR more expensive.
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The BM867s has the dual display (larger, but also the secondary display), a bit better input protection, higher capacitance range, and higher frequency range... but the BM857s is smaller by at least 1cm in every direction, almost 3cm in thickness. Looks like they're probably based on the same chipset, slightly lower power consumption on the BM857s, but that's probably mostly the display.
Personally I like the look of the 867 better, but it's much larger, so I'd probably lean towards the 857 if I were to buy now (though the dual display is nice). It may be a more recent product of theirs, don't remember hearing about it a couple years ago, but maybe I just overlooked it.
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buy the 857s the "S" are backlight revised display
do you really need the usb interface ? and dual display ??
I had an 857s it was rock solid and precise, but i've switched to Gossen Metrawatt
and the 857 i have the calibration procedure ...
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Hi,
I had bought me the BM867s edition+ (with pouch).
With it´s red holster fitted its ~1cm bigger in every dimension than the BM857s .... but yes, its quite a large piece of meat for a handhold MM.
It´s shape is quite ergonomical though ... it fits your palm very well ... probabely better than the brick-alike shape of the BM857s.
The large dual dispay is probabely the most distinct advantage of the BM867s, very crsip, very easy to read, very pleasing.
Since it offers more for the same price I´d opt or the BM867s.
jauu
Calvin
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The 857 is very old legacy design.
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Buy the BRYMEN BM867S. (Unless you really need a single display and a smaller shape.)
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I have a pre-production BM857 and it is quite a good meter. Given the added features of the BM867, I think I would buy this model today, but I typically have no problems with space.
The newer BM857S is an updated design when compared to mine, which probably adds better safety, as I couldn't find any bugs in my "original" BM857.
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To be honest, BM859S has same type and size of single value display as Fluke 87V..
It can easily compete with it if you don't care about AutoHold.
For audio work, you would want 100Khz bandwidth, so 20KHz is still accurate. You might also look for dB mode, so you can make sense of your VU meters...
That would put you in territory of BM859S / BM 869S from Brymen. Both 857 and 867 are specified up to 20kHz and use cheaper spec RMS converter.
You asked why they still make older model when they have a new one? I had a discussion with a member some time ago, and he liked his Fluke 87V better because it has less functions and was simpler to use for his regular tasks. Which is a valid point. So some people might prefer older single line design that works well for them.
Regards,
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Thanks to everyone.
I don't mind the few more cm... (I would actually prefer bench one, if I could afford one)
For audio work, you would want 100Khz bandwidth.
Sounds reasonable, even though I never missed it yet.
For finding some unwanted ultrasound mess, I was usually using my 100MHz scope.
But being able to get accurate AC readings including the higher harmonics could be nice.
But it's additional 40 EUR to get BM859 or additional 60 EUR to get BM869.
So now I need to decide, if I get BM859 or BM867+meter2pc kit (which is also additional 40e and could be pretty usefull for matching parts when building stereo things, or things which need matched transistor pairs)
some people might prefer older single line design that works well for them.
I totally know what you mean. Too much information can be distracting and confusing.
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Presently Brymen's EU store lists the BM869s at €209 inc. VAT. To me, that seems like a bargain. Especially compared to similar models from Fluke or Keysight (Agilent).
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For BM867 20 kHz means it is 1-3 dB down at that frequency. Which means that error can be u to 25%. BM869S 100 KHz guarantees low error still at 20 kHz.
But more important is that 867 is NOT specified for frequencies from 20-40 Hz. And that you really need for audio.
Same for current, 867 is unspecified for more than 1 kHz.
And 2 Ch temp measurement is very useful for power supplies and power amps to check temps, especially that you can measure temp delta (T1-T2) so not only you can see temp but also temp rise to check heatsink design.
I know it is 60 € more (and money is tight, been there..) but in this case if you can in any way afford to go for a 869, I would really recommend to do it. Amortized over years, difference in money will be nothing, for a better instrument.
Regards,
Sinisa
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As Dave pointed out the 857 is the older design. It has only two advantages that I can see. The rectangular case is slightly smaller and lighter and it doesn't wobble as much when propped up on its stand on your bench and you are twisting the knob. (as well as being cheaper). The BM869 can measure and display 2 thermocouples, making it ideal for HVAC workers who want to see inlet/outlet temps.
I have both a BM869 and a BM857a, I like both. I would buy another 869 again if I needed a new full featured handheld. Practically everyone who has one is happy with it.