Brymen BM789

[joeqsmith]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

Again, I want to be clear,  "I do not have any way to check the meter for calibration .."  The standard I have is not in cal, nor are any of my resistors.  That Fluke standard does not provide a 5V level, so you get what you get.   If I need to know what the meter is doing beyond this,  I would have  it calibrated and request a report.  Sure it would cost me about as much as the meter but I fully understand the cost of maintaining a calibration lab.   I have done this for some equipment I own.   In the case of the 869s 500k count mode, any time I have used it, it was for a relative measurement.   I typically do not need the absolute accuracy.   

[J-R]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

Again, I want to be clear,  "I do not have any way to check the meter for calibration .."  The standard I have is not in cal, nor are any of my resistors.  That Fluke standard does not provide a 5V level, so you get what you get.   If I need to know what the meter is doing beyond this,  I would have  it calibrated and request a report.  Sure it would cost me about as much as the meter but I fully understand the cost of maintaining a calibration lab.   I have done this for some equipment I own.   In the case of the 869s 500k count mode, any time I have used it, it was for a relative measurement.   I typically do not need the absolute accuracy.

Fair enough if you don't have a calibrated 5V reference, but what about a 6.5 digit DMM?  DCV Calibration points for the BM869 would be short, 5V, 50V, etc.

[AVGresponding]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

fwiw (not much) my 869S, which has had a hard life, agrees with my (relatively recently) calibrated Fluke 8840A to within around a millivolt or so, with a 5 volt source applied.

[BeBuLamar]

How much is the Brymen 869 or 789 if I were to buy one in the USA? I don't even know where to buy it but I guess it can be done. I haven't seen a Brymen any model in real life and I am curious an want to try them out.

[Fungus]

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.

Seems that way.

Mine is about 5 years old now and either hasn't drifted at all or has drifted at exactly the same rate as my other meters and voltage reverences (which would be too big a coincidence to believe...)

[J-R]

Of course accuracy is going to be a balance between fringe use cases and cost.  The designer of the Fluke 8060A admitted they went the extra mile on it:
 https://theamphour.com/180-an-interview-with-dave-taylor-multi-talented-meter-maker/

In my experience my 87V and 287 (both with calibration data) seem to have still gotten some premium treatment since they far exceed their specs. But I've only had them for about 4 years at this point.

[J-R]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

fwiw (not much) my 869S, which has had a hard life, agrees with my (relatively recently) calibrated Fluke 8840A to within around a millivolt or so, with a 5 volt source applied.

That could be about 100 counts out or more in 500,000 count mode, which is similar to what I and some others have experienced.  After an adjustment some year or so ago, my BM869s is still within about 15 counts worse case, which was about 10c from the calibration temperature and at first power on.  At the same temperature as the calibration and a few minutes after power on, it's within about 1-2 counts.

So this just points out the odd situation of why some of us received units that were so far out, and also points out that it is VERY capable in 500,000 count mode assuming you adjust it if it needs it.

[joeqsmith]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

Again, I want to be clear,  "I do not have any way to check the meter for calibration .."  The standard I have is not in cal, nor are any of my resistors.  That Fluke standard does not provide a 5V level, so you get what you get.   If I need to know what the meter is doing beyond this,  I would have  it calibrated and request a report.  Sure it would cost me about as much as the meter but I fully understand the cost of maintaining a calibration lab.   I have done this for some equipment I own.   In the case of the 869s 500k count mode, any time I have used it, it was for a relative measurement.   I typically do not need the absolute accuracy.

Fair enough if you don't have a calibrated 5V reference, but what about a 6.5 digit DMM?  DCV Calibration points for the BM869 would be short, 5V, 50V, etc.

I had it calibrated last maybe 10-15 years ago.  Thought about having it done after the lighting storm took it out but after seeing it only damaged the GPIB interface, decided to leave it. 

Nothing in my home lab is currently calibrated.  I would only be chasing my tail and adding more error.   

[Veteran68]

How much is the Brymen 869 or 789 if I were to buy one in the USA? I don't even know where to buy it but I guess it can be done. I haven't seen a Brymen any model in real life and I am curious an want to try them out.

Other than Dave's BM235 and BM786 available on Amazon, Brymen-branded meters aren't directly marketed in the US. You can find re-brands like Greenlee and FLIR, but they typically charge a high premium for essentially the same meter (of course you then get a US warranty and support/repair options).

To get a Brymen-branded meter you'll need to import one from a European dealer like TME or Welectron. I've ordered from both, and prefer the latter. Welectron has the best prices even after currency conversion plus have a flat $10 shipping rate for most things that gets it here in about a week.

[Electro Fan]

How much is the Brymen 869 or 789 if I were to buy one in the USA? I don't even know where to buy it but I guess it can be done. I haven't seen a Brymen any model in real life and I am curious an want to try them out.

Other than Dave's BM235 and BM786 available on Amazon, Brymen-branded meters aren't directly marketed in the US. You can find re-brands like Greenlee and FLIR, but they typically charge a high premium for essentially the same meter (of course you then get a US warranty and support/repair options).

To get a Brymen-branded meter you'll need to import one from a European dealer like TME or Welectron. I've ordered from both, and prefer the latter. Welectron has the best prices even after currency conversion plus have a flat $10 shipping rate for most things that gets it here in about a week.

+1 on 789 from Europe

[mwb1100]

To get a Brymen-branded meter you'll need to import one from a European dealer like TME or Welectron. I've ordered from both, and prefer the latter. Welectron has the best prices even after currency conversion plus have a flat $10 shipping rate for most things that gets it here in about a week.

When ordering from welectron to the USA you also don't pay sales tax, which for me is nearly a 10% discount.  And you don't pay VAT, so what you're charged might be less than the prices you're quoted at first (depends on if they know where you are when putting things into the cart).  Tax dodges that work for the little guy!

Email them for an eevblog discount code (5% I think).

[Martin72]

Try "marcoreps5" for the coupon code (5%).

Edit: Pic.

[Hydrawerk]

Benning sells a modified version of BM789. LCD was a bit changed and there is only one channel temperature measurement. I do not see an improvement here. Buttons were renamed and moved.
https://www.benning.de/products-en/testing-measuring-and-safety-equipment/digital-multimeter/high-end-multimeter-mm-7-2.html

[joeqsmith]

For checking DCV accuracy on the BM869 it would be best to test at 5V and using 500,000 count mode.

Again, I want to be clear,  "I do not have any way to check the meter for calibration .."  The standard I have is not in cal, nor are any of my resistors.  That Fluke standard does not provide a 5V level, so you get what you get.   If I need to know what the meter is doing beyond this,  I would have  it calibrated and request a report.  Sure it would cost me about as much as the meter but I fully understand the cost of maintaining a calibration lab.   I have done this for some equipment I own.   In the case of the 869s 500k count mode, any time I have used it, it was for a relative measurement.   I typically do not need the absolute accuracy.

Fair enough if you don't have a calibrated 5V reference, but what about a 6.5 digit DMM?  DCV Calibration points for the BM869 would be short, 5V, 50V, etc.

I had it calibrated last maybe 10-15 years ago.  Thought about having it done after the lighting storm took it out but after seeing it only damaged the GPIB interface, decided to leave it. 

Nothing in my home lab is currently calibrated.  I would only be chasing my tail and adding more error.

But if you like to chasing your tail,  showing the Fluke 731B standard set to 10V with a follower/divider.  My HP34401A (not calibrated) used as a reference and trimmed to 5V.  Seems like this is what you are asking for.   BM869s was is the one supplied by Brymen for my testing.  This meter was subjected to my 50,000 cycle test of the switch.  I also repeated my transient tests on it and damaged it.  I then selected different transistors for the clamp and re-transient tested the meter to 14kV.   So, it doesn't have the original parts installed.  I have never made any attempt to align the meter.  This meter is about 5 years old now but after my abuse, maybe closer to 30 years.          

Still my favorite meter. 

[mwb1100]

Benning sells a modified version of BM789. LCD was a bit changed and there is only one channel temperature measurement. I do not see an improvement here.

One temperature measurement sounds like the EEVblog BM786.  I didn't look close enough to see if they are otherwise functionally the same.  However, I did track down a clue to the cost in a press release (I didn't find any mention of the price on the linked page):

the current selling price of less than 300 euros is extremely reasonable

Instead get the BM786 or BM789 for under 200 EUR (often far less).  Great meters - especially for the price.

[J-R]

- Welectron has various 5% discount codes, I typically use the EEVblog one.  You can just e-mail them to request a code if needed or if they read this thread and discontinue them.  Also, these codes don't apply to all products.

- From photos of the BM78x PCBs, there are other possible model numbers that Brymen has ready to offer, such as 783 up through 789 (of course) and also a Bluetooth option. The Benning 7-2 is not the same as the BM786 as it is missing some things such as nS.  It seems Benning and/or Brymen are planning for other possible models with more features, as the LCD photo shows.  I also find it interesting that the Bluetooth connection icon is present, as also seen on the BM78x series (D icon).  If the Benning came out later, is Brymen still planning to add Bluetooth at some point?  Since they already used up the BM789 model number, perhaps they will move to BM790 or BM789+?

- Making some assumptions about the 731B and 34401A, 27 counts high on the BM869s is not a problem, but if it were mine I would lock in the 5V calibration point just because it's so easy to obtain a calibrated 5V reference and the extra digits are welcome.

- I did discover a situation where the A range (5A/10A) on my BM869s has an accuracy issue vs. my BM789.  Test conditions: briefly verify that a measurement at 0.5A is correct (use auto-range), then push 9A through for 60 seconds.  Notice that the 9A reading should have minimal drift during this time, maybe 5 counts.
Now drop back down to 0.5A and at least with my BM869s the accuracy has suffered significantly and is out of spec.  For example, I got 0.4841A, while spec says no more than 0.0045A off.  The cause appears to be primarily an issue with the zero reference point which you can see if you remove the common input completely (leave A input jack inserted).  There is a large negative offset.
Over time, the BM869s returns to full accuracy.
The BM789 does not drift nearly as much in the same situation (~15 counts off, worse case).
I tested a few other handheld DMMs and some drift was common, but couldn't find any that were anywhere nearly as bad the BM869s.

[joeqsmith]

... but if it were mine I would lock in the 5V calibration point just because it's so easy to obtain a calibrated 5V reference and the extra digits are welcome.

The only time I have used the higher resolution on the BM869s was for relative measurements.  If I need better absolute accuracy, it would be going in for alignment and calibration with a report.  Outside of that, I would just be kidding myself.  I have no reference good enough to give me any level of confidence that any improvements were made. 

[joeqsmith]

... I would lock in the 5V calibration point just because it's so easy to obtain a calibrated 5V reference and the extra digits are welcome.

I looked to see what it would cost to rent a Fluke calibrator but would have to create an account just to get a quote.  I'm sure sending the meter out would be less costly but I would need to talk with the cal house to get a quote on alignment.  Guessing they would need to manually align the BM869s.   

I'm interested in hearing about the easy to obtain reference you mention.  I'm not thinking I could find anything NIST traceable easily. 

There are those cheap references on ebay but  I'm sure you're not suggesting using one of them as your standard to align your meters with.   I could have the HP sent off and get a report, then transfer from that.  A pain but may be the easiest way to go.

[joeqsmith]

https://voltagestandard.com/01%25-voltage-references

The VREF5-01 features a 5V output, accurate within 0.01%  (output guaranteed to be between 4.9995 and 5.0005 Volts) for a minimum of 8 months.

My BM869s was 0.00027 from my HP.   

There's this one:
https://dmmcheckplus.com/

According to their website, their cal standards are out of date.  So would I trust to use it to align a meter, nope.
https://img1.wsimg.com/blobby/go/c544540f-524c-4b38-8d0c-cbfda88bf37a/downloads/2022%203458A%20Calibration.pdf?ver=1691065892806

Just chasing your tail with this stuff.  Maybe good for a sanity check like my white box but if I need accuracy, the meters would be properly aligned or just calibrated with a report so I can calculate the error.   

[EEVblog]

Benning sells a modified version of BM789. LCD was a bit changed and there is only one channel temperature measurement. I do not see an improvement here.

One temperature measurement sounds like the EEVblog BM786.

The BM786 is exclusive to me.

[J-R]

Yes, I was thinking of Doug's VREF-01 product.  I've had two of them for over 4 years and have the calibration data for each yearly calibration.  For the 5V reference, 1 year drift was:
5.00009V
5.00012V
5.00013V
(Each year it is set to exactly 5.00000V)
HOWEVER, the best course of action is to use the reference as soon as you receive it, since the drift will be negligible.  Doug also provides the calibration temperature so you can match it to your environment.  I always check mine right after receiving them and they are spot on.


I have not found the DMMCheckPlus to be QUITE as awesome, as the calibration printout only reports 5.0000V while Doug adds an extra digit to the as-received and post-calibration measurements.

Russ @ DMMCheckPlus has just not updated the website with the current equipment calibration dates.  I received my unit back a couple months ago and it shows the 3458A with a calibration due date of 5/01/2024.


For hobby use, having at least some basic references that have been mailed out for verification is plenty good to take things up a notch.  I agree the BM869s at face value doesn't appear too far off, but without at least something to use as a reference we are mostly guessing, although the 34401A is pretty trustworthy in general.

So with that said, I would totally vote for shipping that 34401A out for calibration.  It's nice to have something that can be expected to be very stable due to age and the money is far better spent there than with the BM869s.

[joeqsmith]

Yes, I was thinking of Doug's VREF-01 product.  I've had two of them for over 4 years and have the calibration data for each yearly calibration.
....
(Each year it is set to exactly 5.00000V)

It sounds like you are having them align your VREF-01 every year to some () reference they have.  We assume that their reference is in cal and they provide you with that error report.  Otherwise, the exactly 5.000000V is meaningless.   There is a reason I want that standard tied to NIST under current cal. 

For hobby use, having at least some basic references that have been mailed out for verification is plenty good to take things up a notch.

Hard to say really.  You may be doing more harm that good aligning your meters to these cheap references.  Personally, I cross check my Fluke standard with the old HP and then against the BM869s, good enough.  Getting anything better, I am going with a calibration lab that has the proper equipment to calibrate them (not align).   Sure, it's going to cost me some cash and down time but beats chasing your tail if you really need that level of absolute accuracy.   

I've taken my white box into work and checked it against equipment that is in current calibration.  It's good enough to tell me if the meters I test have started to fail.  Really though, that's all I use it for. 

I saved an old Fluke thermal RMS bench meter from the recycle that needed a lot of work.  Once repaired, I did go through the alignment using my old HP34401A as a reference.   I left the AC section alone as the Fluke would require something much better than the HP to align it.    That's about as close as I have come to trying to align a meter.  I would never suggest ether meter is in cal. 

I am running a long term poor man's drift study on a cheap handheld meter that I hacked up.   Looks like it's due to me checked again.  Keep in mind that non of the standards used are calibrated.   What we can see if that at least this particular meter doesn't live up to all they hype about drift on cheap meters.   

[J-R]

The voltage references from VoltageStandard.com and DMMCheckplus.com are adjusted to their stated value at each calibration.  This is how they are designed/marketed.  I'm sure you could decline the adjustment, but there are advantages to having them set to a specific value.

Of course Doug @ Voltage Standard also uses a calibrated 3458A, currently due for calibration on 3/22/2024: https://voltagestandard.com/001%25-10v-reference


Actually it's easy to say: I have four calibrated DMMs with data and five calibrated references with data so I wouldn't have suggested using the VREF-01 to set the BM869s 5V calibration point if I thought it would do more harm than good.  It's been well documented in other threads that the BM869s can be off by quite a bit and yearly calibrations/adjustments can tighten it up to make it significantly better.  I've also documented that the VREF-01 is excellent and best right after calibration/adjustment.

But as I said that is really just a small step above having no calibrated equipment.  So why not ship the 34401A and 731B off once for calibration?  Age is great for stability.  Then snag the VREF10 to use for yearly verifications.

[joeqsmith]

So why not ship the 34401A and 731B off once for calibration?  Age is great for stability.  Then snag the VREF10 to use for yearly verifications.

As I have stated, I did have the HP in for cal 10-15 years ago.  I had bought the meter brand new from HP when it was first released and was curious how it had changed so I had a full report created.  Having my equipment calibrated to NIST standards wouldn't enhance my hobby.   Using a cheap standards to try and align things, even less so. 

Of course, shipping out the equipment poses a risk.  Then there is the question of if the company doing the work is actually capable. 

[NoisyBoy]

Hi Joe,

I understand your concern with shipping equipments.  Depending on where your lab is, it may worth checking around.  Both Keysight and a local cal lab came to my lab to pick up my DMMs when calibrations are due.  The local cal lab hand deliver the DMMs back when it is done, Keysight ship it directly from their cal lab (which is not local) in their own packaging, which was very carefully packaged. 

Good luck, in my 34401As, 34461A, and 34465A, they are extremely stable, annual drift are minimal, usually they only have to adjust 1-2 alignments in different ranges.  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.