Brymen BM789

[Neutrion]

The following Brymen meters have 20/second update in REC (aka MAX/MIN) mode (not a comprehensive list):

  - BM257s
  - BM525s
  - BM817s (Amprobe AM-270)

The 20/second display update isn't really useful as far as the display goes - if the numbers are changing fast, they're just a blur - better to look at the bargraph.  Of course, the important thing is it helps ensure that the meter will catch very short MAX & MIN durations.

The 10/s update on the BM789's display is not a blur, but "well" readable, so it could be useful sometimes when the baragraphs resolution is not enough.

As far as busting the 87V, I'd say "not so fast"!  The 87V's default MIN/MAX record rate is 100ms (10/second), just like the BM789.  It's just that it doesn't update the digital display any faster (the min/max is taken from the bargraph reading).

Also, the Fluke 87V and many of the Brymens support a "Peak" or "Crest" mode where the min/max is captured for very short transients (0.25ms for the 87V and 0.25ms-5ms for the Brymens depending on the model).  In this mode the display doesn't update continuously - it shows the MAX or MIN value (whichever you select)

The BM789's manual doesnt say anything about the different display update rate, but in REC mode it says the signal duration must be DC 300ms AC 460ms and there is the nominal update rate mentioned, I suppose for the measurement. Because it is 10 for AC but the display stays at 5/sec.
Crest mode says 0,35 ms signal duration. But it goes a bit lower.
JoeQSmith did once a test of the crest modes of some meters, unfotunately the BM789 was not there yet.

It would be a nice test to see how the meters behave with singe glitches, and different signal heights, especially in Amps mode.

But anyway in display update the BM789 beats the Fluke, also in normal mode and in baragraph wiev 

[joeqsmith]

...
JoeQSmith did once a test of the crest modes of some meters, unfotunately the BM789 was not there yet.

It would be a nice test to see how the meters behave with singe glitches, and different signal heights, especially in Amps mode.
...

I could repeat it with what ever meters I have.  I think I had used a constant height and varied the pulse width.  Because the meters all work differently, it's a manual process.   Adding different signal amplitudes and modes would add a bit of time.   Currently my office is a big mess with several projects going on.  Maybe once things settle down we can set it up.

[mwb1100]

The 10/s update on the BM789's display is not a blur, but "well" readable, so it could be useful sometimes when the baragraphs resolution is not enough.

You're right that the 10/second update isn't too bad.  I found the meters with 20/second update were just a blur when things were changing.

The BM789's manual doesnt say anything about the different display update rate, but in REC mode it says the signal duration must be DC 300ms AC 460ms and there is the nominal update rate mentioned, I suppose for the measurement. Because it is 10 for AC but the display stays at 5/sec.

I only verified that the nominal update rate of 10/second in the table for DCV seemed to match up with what I saw and I then assumed that the REC update rates in that table for other modes would match the display updates in REC mode.  But I didn't actually test anything other than DCV (in particular the 10/second the table also shows for ACV).  Just goes to show that you have to verify everything!

[Neutrion]

...
JoeQSmith did once a test of the crest modes of some meters, unfotunately the BM789 was not there yet.

It would be a nice test to see how the meters behave with singe glitches, and different signal heights, especially in Amps mode.
...

I could repeat it with what ever meters I have.  I think I had used a constant height and varied the pulse width.  Because the meters all work differently, it's a manual process.   Adding different signal amplitudes and modes would add a bit of time.   Currently my office is a big mess with several projects going on.  Maybe once things settle down we can set it up.

It would be great! Especially to know the blind time of the meters, or if the update rate is really only a few per seconds, so whether glitches close to eachoder pass through without getting catched.
So the waveform update per second basically.
I tried to find the mentioned video of yours without luck, can yan you tell which one it was?

I only verified that the nominal update rate of 10/second in the table for DCV seemed to match up with what I saw and I then assumed that the REC update rates in that table for other modes would match the display updates in REC mode.  But I didn't actually test anything other than DCV (in particular the 10/second the table also shows for ACV).  Just goes to show that you have to verify everything!

If you have an another FW than 08 you could test whether it may gives you 10/sec with AC as well. But I don't think it will.  Maybe with a faster changing higher than 50Hz sine wave?

[mwb1100]

If you have an another FW than 08 you could test whether it may gives you 10/sec with AC as well. But I don't think it will.  Maybe with a faster changing higher than 50Hz sine wave?

Mine (BM786) is also FW 08. I'm sure your observations are correct (also I'm fine with 5/sec update).

[floobydust]

Weeks ago, I contacted Emerson/Greenlee about doing Brymen product service/repair and received no response.
The website can only give you an RMA # from a picklist of valid Greenlee products- so you can't enter anything alien.
Until I hear otherwise, it's a myth you can get Brymen anything in North America - sales and service or calibration.

My theory is they are locked out of the region due to contract with Brymen as an OEM.
1,117kg or 66 cartons is a lot of multimeters per the HTS code, on the container ship One Theseus. It ain't test leads lol.

[joeqsmith]

...
JoeQSmith did once a test of the crest modes of some meters, unfotunately the BM789 was not there yet.

It would be a nice test to see how the meters behave with singe glitches, and different signal heights, especially in Amps mode.
...

I could repeat it with what ever meters I have.  I think I had used a constant height and varied the pulse width.  Because the meters all work differently, it's a manual process.   Adding different signal amplitudes and modes would add a bit of time.   Currently my office is a big mess with several projects going on.  Maybe once things settle down we can set it up.

It would be great! Especially to know the blind time of the meters, or if the update rate is really only a few per seconds, so whether glitches close to eachoder pass through without getting catched.
So the waveform update per second basically.
I tried to find the mentioned video of yours without luck, can yan you tell which one it was?

I think I have ran it a few times.  This was from about 8 years ago with the 87V.   
https://youtu.be/UZPjG892C40?t=95

I was firing a one-shot and reducing the duration.  The meters have to be reset so I am not sure what you are asking for with the blind time.  Personally, I wouldn't have much use for feature.  If I am looking at short pulses, I am most likely wanting more detail than what the meters can provide.     

[Neutrion]

Yes, this was it. Was it really one single pulse, so the scope was just stoped after it? As it seems on the right side of the screen as if another pulse was coming.
You mean by reset, to reset the screen I suppose?
What I meant that if the update rate 10 per sec doesn't mean screen updating, than it could mean that with two short impulses after each other with the second one bigger (so manual screen updating would not be necessary) if it is within 1/10 second of eachother, the second one could pass unnoticed.
I am interested in how rare single glitches might could go unnoticed under certain circumstances.
Or with tricky  waveforms.
Like a VFD puts out a single burst of a PWM waveform with only a few squarewaves, which might won't get properly recognized. Or any of the waveforms you tested the RMS funcions with. This is where min/max, crest etc would be used with the meter, especially with higher voltages before getting a scope.

And of course if the 10/sec would be only screen update, maybe later firmwares got it right for AC as well.

[joeqsmith]

Yes, this was it. Was it really one single pulse, so the scope was just stoped after it? As it seems on the right side of the screen as if another pulse was coming.
You mean by reset, to reset the screen I suppose?

I just watched it and indeed it is live data.  For some reason I was thinking it was a one-shot.   So, yes it is not a single pulse.  Seems the 869s requires you to reset the meter to start a new measurement but maybe not.  Again, I own a scope so this isn't something I would normally have a use for.   

What I meant that if the update rate 10 per sec doesn't mean screen updating, than it could mean that with two short impulses after each other with the second one bigger (so manual screen updating would not be necessary) if it is within 1/10 second of eachother, the second one could pass unnoticed.

I would imagine some meters have hardware to do the peak detect but maybe not.   I dare say the update rate of the CEM is much slower the pulse we are trying to measure.

I am interested in how rare single glitches might could go unnoticed under certain circumstances.
Or with tricky  waveforms.
Like a VFD puts out a single burst of a PWM waveform with only a few squarewaves, which might won't get properly recognized. Or any of the waveforms you tested the RMS funcions with. This is where min/max, crest etc would be used with the meter, especially with higher voltages before getting a scope.

And of course if the 10/sec would be only screen update, maybe later firmwares got it right for AC as well.

That's where the scope come into play.   Well, for me anyway.   That old Fluke scope meter has been nice to have.   

[TDA1541AS2]

Hi all,
I just received my new BM789 DMM firmware V12.
In regards to the duty cycle function being within the mV setting, what would the upper voltage limit be for taking duty cycle measurements? Could I safely use it with mains voltages? 240VAC
Thanks,
Daniel

[joeqsmith]

Guessing AI bot but hey, I'll bite.   Are you well educated?  Skilled electrician?  I wouldn't have my sister working on anything mains even with a proper handheld meter. 

[mastershake]

To be clear - there is no North American support for these Brymen multimeters such as repair, calibration, firmware updates? It's gotta be shipped trans-ocean for any of that?

correct if you want support you have to buy it under the greenlee brand instead but the prices are MUCH higher that way sometimes double even.

[EEVblog]

To be clear - there is no North American support for these Brymen multimeters such as repair, calibration, firmware updates? It's gotta be shipped trans-ocean for any of that?

correct if you want support you have to buy it under the greenlee brand instead but the prices are MUCH higher that way sometimes double even.

I think I'd happily offer a "lifetime" warranty for double the price, or even 50% more.

[TDA1541AS2]

[

Guessing AI bot but hey, I'll bite.   Are you well educated?  Skilled electrician?  I wouldn't have my sister working on anything mains even with a proper handheld meter. 

Not AI bot. (Whatever that is in this warped world)
I'm an electronics engineer with audio interest.
I'm asking the above (re: duty cycle measurements) as I had a cheapo dmm that had the duty cycle available in the normal volts range and able to take the measurement at 240vac levels.
But I guess I wouldn't be able to it with the BM789. (OR can I?)
Not willing to damage my meter or test it without a good understanding.
Also, the Brymen manual has bugger all stated in the specs regarding the operational limits of the mV range.
 

[Caliaxy]

Duty cycle is only specified in the manual for “5V logic”. I don’t think you’ll damage the meter by applying a higher voltage on the mV range, but you’ll get an “overload” reading.

[TDA1541AS2]

Ok, thank you.
That makes sense 

[joeqsmith]

[

Guessing AI bot but hey, I'll bite.   Are you well educated?  Skilled electrician?  I wouldn't have my sister working on anything mains even with a proper handheld meter. 

Not AI bot. (Whatever that is in this warped world)
I'm an electronics engineer with audio interest.
I'm asking the above (re: duty cycle measurements) as I had a cheapo dmm that had the duty cycle available in the normal volts range and able to take the measurement at 240vac levels.
But I guess I wouldn't be able to it with the BM789. (OR can I?)
Not willing to damage my meter or test it without a good understanding.
Also, the Brymen manual has bugger all stated in the specs regarding the operational limits of the mV range.
 

....Could I safely use it with mains voltages? 240VAC

When you asked the above question, you were not referring to your personal safety but rather the meters ability to withstand it.   "... and able to take the measurement at 240vac levels"

From that perspective, I did much worse to this meter than what you are proposing and it held up just fine.  That said, let me try it tonight and see if I can get a good measurement.     

[joeqsmith]

Being a EE myself, I can't think of one time where I wanted to measure the duty cycle of the mains but what ever floats your boat.   Both meters in parallel, 60Hz sinewaveish, 240V.   Of course, you follow my videos, you would know this isn't going to pose a problem for this particular meter.   Even some of the cheapest ones I look at with their lack of a surge resistor and tiny 5mm PTCs would handle this just fine.       

[Hydrawerk]

It is time for a partial teardown of BM789. One screw is missing, but I do not care.

[EEVblog]

I've given up all hope of them releasing the Bluetooth version.

[floobydust]

How much memory do they have left?

[Astray]

Curious, does anyone know if there's an accessory that would allow me to use a BM786 or BM789 similar to a clamping multimeter?

I understand there's an Electrical Field detection feature already available but it would be nice if there was a clamp I could attach to the multimeter's inputs to have it estimate the current in a wire, instead of buying a whole new multimeter just for the clamping function.

[BILLPOD]

if there was a clamp I could attach to the multimeter's inputs to have it estimate the current in a wire, instead of buying a whole new multimeter just for the clamping function.
[/quote]

AliExpress sells a clamp accessory for their UT117C meter.  It is model
 UT-CS05A and is supposedly good for 400A   of AC current.   I have tried it on other meters I have with a mV range and it works for me, although I haven't tried it it on over 8 Amps.  Also, for me it wouldn't register anything under 1.5 A.   It was only a $20 accessory from Aliexpress.

[TomKatt]

Curious, does anyone know if there's an accessory that would allow me to use a BM786 or BM789 similar to a clamping multimeter?

There are many current clamps available for multimeters - I’ve got an Amprobe 237 that measures AC/DC 20A / 200A that works pretty well. It scales amps to mV so you read the voltage that represents the current.  Works well and has safety banana plugs that fit into the multimeter.  If I need super accurate measurements for lower current I just use the multimeter current feature.

On topic, I’ve got a Greenlee DM820A which is a Brymen rebadge - I think the equivalent Brymen model is am 867s.  As good as the Flukes the maintenance guys have at my shop. Lucked out on eBay and got it for $50 with carry bag and accessories  . Makes a great companion for my BM235 I got here - I love the flashing continuity display on the 235.

[joeqsmith]

Curious, does anyone know if there's an accessory that would allow me to use a BM786 or BM789 similar to a clamping multimeter?

I understand there's an Electrical Field detection feature already available but it would be nice if there was a clamp I could attach to the multimeter's inputs to have it estimate the current in a wire, instead of buying a whole new multimeter just for the clamping function.

While you don't provide any specific requirements beyond it having to be a clamp,  I bought one of these new when Radio Shack was still around. 
https://www.ebay.com/p/1022934766