New Brymen BM2257 Multimeter

[mwb1100]

Dave can you tell me more about the new brymen multimeters. I wish they would add the 2257 features to my favorite bm857s. The 86x 82x 83x series is too big for me

@joeqsmith has posted about a new Brymen model (BM788BT) along with a link to a video here: https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860739/#msg5860739

It seems this (or an eevblog variation) is the new meter Dave alluded to.

[bte]

Dave can you tell me more about the new brymen multimeters. I wish they would add the 2257 features to my favorite bm857s. The 86x 82x 83x series is too big for me

@joeqsmith has posted about a new Brymen model (BM788BT) along with a link to a video here: https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860739/#msg5860739

It seems this (or an eevblog variation) is the new meter Dave alluded to.

It is...

https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860759/#msg5860759

[EEVblog]

Not sure if it was stated specifically previously, but the BM2257 PCB has markings for: 2251, 2253, 2255, 2256, 2257 & 2258.  Byrmen currently only has the BM2251 and BM2257 listed in their datasheet.

They do that for customers who want to brand their own slightly different model. e.g. me with the BM786, it had a slightly different feature set so I took the available BM786 number.
And the new BM780BT series, I have the BM787BT

[EEVblog]

@joeqsmith has posted about a new Brymen model (BM788BT) along with a link to a video here: https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860739/#msg5860739
It seems this (or an eevblog variation) is the new meter Dave alluded to.

Yes, new thread here:
https://www.eevblog.com/forum/testgear/new-brymen-bluetooth-bm787bt-multimeter/

[Sebekh]

Hi Dave I have a request could you compare the crest function in 2257 with another bm7xx or bm8xx and present it on YouTube I think it will be interesting I think brymen is the only one that has this function.I think You have the equipment and knowledge to do it well if You have the time

[J-R]

Not sure if it was stated specifically previously, but the BM2257 PCB has markings for: 2251, 2253, 2255, 2256, 2257 & 2258.  Byrmen currently only has the BM2251 and BM2257 listed in their datasheet.

They do that for customers who want to brand their own slightly different model. e.g. me with the BM786, it had a slightly different feature set so I took the available BM786 number.
And the new BM780BT series, I have the BM787BT

Yes, I knew this but still found it quite interesting that they had so many listed.  They must be dreaming big with this model...

[puxe]

I suspect this 'Crest' function is the same as the 'Peak' function on my recent "NJTY T58C 9999 Counts Inductance Digital Multimeter".
Yet another inexpensive meter, but I like it, with the auto backlight and illuminated jack sockets etc.   it also has pretty fast continuity responsive, when I use with cheap gold/ silicone leads ( PT1032 £3). It seems accurate enough and has a level of fused inputs, sufficient for electronics.  This model also provides Inductance testing, which did give a reasonable value on the limited testing I did.
Just mentioned because 'Peak' function is not all that common; TBC if it works as expected as I haven't tried it.

[J-R]

There is a bit of information in the manuals about the "CREST mode (Instantaneous Peak Hold)" feature:

BM225x:
Current or Voltage peak values in durations as short as 5ms
Resolution: 6000 counts
Specified accuracy +/- 100 digits for changes > 0.35ms in duration
Availability: Voltage and Current functions


BM78x:
Current or voltage peak values in duration as short as 0.25ms
Resolution: 6000 counts
Add ± 250 digits to specified accuracy for changes in duration
> 1ms for VFD-ACV function;
> 350μs for other Voltage and Current functions

[puxe]

That's interesting.

I'm not at home for a month and don't have the paper manual for the NJTY meter.   Can't find any online copy either for it (or the Richmeters equivalent).

The logic must be that there is a distinction between Max/Min function and Peak, which is of short duration.
 
Obviously a scope would be more suitable, but I guess if the short duration matches the peak, this would be a suitable method to capture the peak event.

[5U4GB]

Hi Dave I have a request could you compare the crest function in 2257 with another bm7xx or bm8xx and present it on YouTube I think it will be interesting I think brymen is the only one that has this function.I think You have the equipment and knowledge to do it well if You have the time

AFAIK only Brymen call it that but a lot of other meters have it too, with names like Peak and Max Hold.  For example the Klein MM720, with specs and features very similar to the 2257, has MIN/MAX buttons for this - the reason I mention that one specifically is because it's a toss-up between that and the 2257 given their feature and price similarity.  Of course the Klein one isn't blue...

[puxe]

Are you sure the Klein Max/Min function has the additional 'peak/crest' short duration functionality and not just 'normal' max/min capture like many other meters?

Edit.... I just downloaded the MM720 manual and it looks like simple max/min functionality with my quick look

[Sebekh]

well not every dmm is that fast
https://youtu.be/cMSuF_RdgW0?feature=shared

[mwb1100]

Brymen's crest function shows the max/min of the AC waveform, not the max/min of the AC RMS value.  Getting the max/min (and sometimes avg) value of the RMS AC is done with the "REC" button.  Brymen's REC function is more commonly called "MAX/MIN" - I think that some Brymen meters also use that label, but for some reason they seem to prefer "REC".

See photos for what the CREST function shows on a line with AC RMS 118.3V.  Theoretically the CREST value should be 1.414 times the RMS value.

[shapirus]

See photos for what the CREST function shows on a line with AC RMS 118.3V.  Theoretically the CREST value should be 1.414 times the RMS value.

That looks quite right. The mains sine wave often has somewhat flattened tops these days.
It may be interesting to cross-check this with an oscilloscope.

What will be much more interesting, though, is to compare Crest mode measurements with oscilloscope captures for short pulses, especially as short as the durations specified in the manual and shorter.

[bdunham7]

AFAIK only Brymen call it that but a lot of other meters have it too, with names like Peak and Max Hold. 

I thought it was confusing too.  The only other meter I can recall seeing the term "crest" used is my Fluke 289 which has a "crest factor" function--but that displays the actual crest factor, as in "1.4" for my mains voltage.  The upper and lower peak of the mains is given by the peak function in either the AC or DC ranges.

[5U4GB]

Are you sure the Klein Max/Min function has the additional 'peak/crest' short duration functionality and not just 'normal' max/min capture like many other meters?

Edit.... I just downloaded the MM720 manual and it looks like simple max/min functionality with my quick look

Yeah, I don't have a 2257 (yet) so had assumed it was everyone else's MAX, however looking at the manual it looks like Brymen hide their MIN/MAX behind R(ecord).  However also from the manual, CREST also indicates as MIN/MAX:

The meter beeps when a new R MAX (maximum) or MIN (minimum) reading is updated. [...] The meter beeps when a new C MAX  (maximum) or MIN (minimum) reading is updated.

In terms of ease of use I'd say I rather prefer the Klein UI, the Brymen one looks too much like an APL keyboard transferred to a multimeter.  But as I said earlier, the Klein isn't blue :-).

[EEVblog]

Brymen's crest function shows the max/min of the AC waveform, not the max/min of the AC RMS value.  Getting the max/min (and sometimes avg) value of the RMS AC is done with the "REC" button.  Brymen's REC function is more commonly called "MAX/MIN" - I think that some Brymen meters also use that label, but for some reason they seem to prefer "REC".

Crest mode is, from the manual, "Instantaneous PEAK-HOLD" to capture current or voltage peak values in duration as short as 0.25ms
They advertise it for uses like measuring in-rush current for example.

Interestingly I gave Mehdi from Electroboom a BM2257 the other day (he's was in Sydney) and he saw the REC button and assumed it was a data logging record function, I had to explain it was Brymen version of MIN/MAX mode.
This is on the walkaround video we did.
https://youtu.be/EIszL6M8CiI?si=6G7AZwz0VjQvltoo&t=2610

[2X]

Hi guys, do you know if this multimeter is available on european store like welectron?

[Furna]

Hi guys, do you know if this multimeter is available on european store like welectron?

Welectron never listed it on their web site; TME.EU did but currently has 0 in stock.
Personally bought one from Dave's shop and had 0 issue.

[EEVblog]

Welectron never listed it on their web site; TME.EU did but currently has 0 in stock.
Personally bought one from Dave's shop and had 0 issue.

I have a ton of stock.
Use coupon code orderofmagnitude for 10% off.

[5U4GB]

I have a ton of stock.
Use coupon code orderofmagnitude for 10% off.

Thanks, just ordered one!

[2X]

Welectron never listed it on their web site; TME.EU did but currently has 0 in stock.
Personally bought one from Dave's shop and had 0 issue.

I have a ton of stock.
Use coupon code orderofmagnitude for 10% off.

Thanks Dave.

[5U4GB]

Thanks, just ordered one!

A followup question, I've just had an email telling me:

Track your order with Shop
With the Shop app you can track your order right to your doorstep.
Download Shop

However with something magical known as a Tracking Number I can also track the order without having to install someone's custom app to do it.  Is this just Shop being pre-emptive to get me to install their app?

[Furna]

However with something magical known as a Tracking Number I can also track the order without having to install someone's custom app to do it.  Is this just Shop being pre-emptive to get me to install their app?

I was able to track without installing anything ... unfotunately I cannot recall where I spotted the tracking number.

[mwb1100]

However with something magical known as a Tracking Number I can also track the order without having to install someone's custom app to do it.  Is this just Shop being pre-emptive to get me to install their app?

When the package ships you'll get an email from sales@eevblog.com with a URL that has a tracking number.