Brymen BM869 review – By the eye of the Industrial electrician.

[Crumble]

I might not be asking this on the proper place, but does anyone know what the 's' suffix on the typenumber means? I found it to be present/absent at random. Even on the Brymen site it shows as being the BM869s, but the unit on the picture shows no suffix. 

Regards,
Crumble

[joeqsmith]

I might not be asking this on the proper place, but does anyone know what the 's' suffix on the typenumber means? I found it to be present/absent at random. Even on the Brymen site it shows as being the BM869s, but the unit on the picture shows no suffix. 

Regards,
Crumble

I was asked so many times I finally asked Brymen, assuming they may know.  See below:

Hello Joe,

BM869s is the upgraded model of BM869 to meet the requirements of the latest 61010-1 3rd Edition. All of their functions, ranges & features are maintained the same. Only their input protection circuits are with slight difference.

[TheBo]

I might not be asking this on the proper place, but does anyone know what the 's' suffix on the typenumber means? I found it to be present/absent at random. Even on the Brymen site it shows as being the BM869s, but the unit on the picture shows no suffix. 

Regards,
Crumble

I was asked so many times I finally asked Brymen, assuming they may know.  See below:

Hello Joe,

BM869s is the upgraded model of BM869 to meet the requirements of the latest 61010-1 3rd Edition. All of their functions, ranges & features are maintained the same. Only their input protection circuits are with slight difference.

In the case of the 857, didn't the "s" version meaning  it has the improved backlight from the 857a ?

OT: Mr joe, your videos are cool    i absolutely LOVE them, you are the most checked per week in my 20 plus followed channels. And sorry for faking your follower counts, i've subscribed it with my 2 different youtube accounts i hope just to learn more and more from you and and maybe see varied videos since i have just schoolastic education. Sorry for the OT

[joeqsmith]

OT: Mr joe, your videos are cool    i absolutely LOVE them, you are the most checked per week in my 20 plus followed channels. And sorry for faking your follower counts, i've subscribed it with my 2 different youtube accounts i hope just to learn more and more from you and and maybe see varied videos since i have just schoolastic education. Sorry for the OT

I wondered why I had so many followers!     Glad you enjoy them.  Up coming one will be about the current shunts I saved from some of the ones I damaged.

[Crumble]

I was asked so many times I finally asked Brymen, assuming they may know. [...]

Thanks for answering, because I initially googled it, and failed. Imagine that, in 2017.  Hopefully, the next one won't have to. 

OT: Mr joe, your videos are cool    i absolutely LOVE them, you are the most checked per week in my 20 plus followed channels. And sorry for faking your follower counts, i've subscribed it with my 2 different youtube accounts i hope just to learn more and more from you and and maybe see varied videos since i have just schoolastic education. Sorry for the OT

+1 For that! You may know you were the intial reason I started out considering Brymen as an option. Good work, keep it up! 

Regards,
Crumble

[Ingo]

Hi,

after reading the impressive review of Kiriakos and after informing myself at the net, I also bought the BM869s. (I use for years a VC920 Voltcraft from Conrad electronics.)

I am satisfied with this meter but I have a question for any user of that Multimeter:

Could you please use the meter for a DCV measurement at resolution of 50.000 as well as 500.000 count and measure a voltage source (for example a fresh battery or a different stable DC source) and then interchange the voltage probes so that the measured voltage changes its sign. Do you get the same absolute value? What is the difference you can measure?
I wrote to Brymen to aks if there is a point in the calibration procedure to compensate such differences and I was told that there is no such possibility.

Greetings from Potsdam

Ingo.

[chronos42]

Hi,

At my 869S I see a difference of approximate 20 counts when I reverse the voltage in the 500.000 count mode (5V).


Grüße aus Karlsruhe nach Potsdam

[Wytnucls]

Wow! 2 counts is huge. Accuracy is supposed to be 0.05%+2 in the 5V range.
Calibration is usually done with positive and negative DC voltages, according to my DAkkS calibration results.

Did the test on a Gossen 26S and Fluke 867B, both 30,000 count meters, with a voltage reference. There was no count difference between positive and negative voltages (2.5V and 5V).

[coromonadalix]

the "s" version are an upgraded back light version ... and maybe pcb or functions updates, but the back light where the first thing they changed.

[ProBang2]

Hi,

some more data:

2.5006	-  2.5006
2.50063	-  2.50069
5.0020	-  5.0022
5.00205	-  5.00224
7.502	-  7.502
7.5026	-  7.5031
10.003	-  10.004
10.0039	-  10.0044

Disappointing. Even the readings of the Uni-T UT61E are - no matter if with correct or reversed polarity - identical...   


Grüße aus dem Sauerland

Hartmut

[ProBang2]

the "s" version are an upgraded back light version ... and maybe pcb or functions updates, but the back light where the first thing they changed.

The backlight was upgradet at the 857s and 859s.
(If you ask me: Damn necessary...)
Not changed: The backlight of the 867s and 869s. There was no need for changing anything.
But all series with the added "s" were adapted to the new IEC regulations.

[evava]

Another test that joeqsmith could perform on every meter 
Can we ask you Joe?

Hi,

some more data:

2.5006	-  2.5006
2.50063	-  2.50069
5.0020	-  5.0022
5.00205	-  5.00224
7.502	-  7.502
7.5026	-  7.5031
10.003	-  10.004
10.0039	-  10.0044

Disappointing. Even the readings of the Uni-T UT61E are - no matter if with correct or reversed polarity - identical...   


Grüße aus dem Sauerland

Hartmut

[exe]

Disappointing. Even the readings of the Uni-T UT61E are - no matter if with correct or reversed polarity - identical...   

But it's still within specs, right? Although, I understand you feelings. I like when tools perform well.

[evava]

I wonder about your 1200000 counts meter Metrahit 30M?
Also no count difference?

Did the test on a Gossen 26S and Fluke 867B, both 30,000 count meters, with a voltage reference. There was no count difference between positive and negative voltages (2.5V and 5V).

[Wytnucls]

The 30M is out of calibration now.
Original calibration certificate:
1V 0.999 997 -0.999 997  10uV accuracy uncertainty.
10V 9.999 97 -9.999 93 100uV accuracy uncertainty.

Ran it anyway, after some warm-up:
voltage reference 5.000 05 (out of calibration)
Measured   05.000 12    -05.000 12  (filter set at 16 samples for both measurements).

[evava]

Nice your all Gossen metres!
Thank you!

My Fluke 289 (bought used), after 10min :
battery aaa, alkaline, used:
+1.4701 V
-1.4699 V

So 2 counts difference seems to be common.

Hopefully we are not too offtopic...

[ebastler]

Wow! 2 counts is huge. Accuracy is supposed to be 0.05%+2 in the 5V range.

Unless I am mistaken, 0,05% of 5.00000V is 0.00250V, i.e. 250 counts in 500,000 count mode.
So 2 counts, or even 20 counts as you probably meant to write, is not bad at all.

[cola_sorbet]

Thanks for the great review, I just picked up a new BM-869s a few weeks ago to replace my Fluke. After long consideration and help from these forums I'm glad I decided to go with the Brymen.

[joeqsmith]

Another test that joeqsmith could perform on every meter 
Can we ask you Joe?

Do you just want to see how much mine change?   My guess is meters like the my free one don't change.  They just can't read down low enough to detect the offset.   Better meters like my Bymen and Gossen, I expect would shift the most counts.  The TPI, UNI-T and CEM I would expect to shift less (less digits). 

Or are you just wanting to know going forward if I can show this as part of the testing?

[evava]

Do you just want to see how much mine change?   My guess is meters like the my free one don't change.  They just can't read down low enough to detect the offset.   Better meters like my Bymen and Gossen, I expect would shift the most counts.  The TPI, UNI-T and CEM I would expect to shift less (less digits). 

Or are you just wanting to know going forward if I can show this as part of the testing?

I wonder mainly about UT181a and of course upcoming GW121.
And as part of your future testing it would be nice to know more about meters.

I know now that 2 counts difference is probably normal and common, but I would like if there was no count difference at all when interchanging the probes.

[Wytnucls]

Wow! 2 counts is huge. Accuracy is supposed to be 0.05%+2 in the 5V range.

Unless I am mistaken, 0,05% of 5.00000V is 0.00250V, i.e. 250 counts in 500,000 count mode.
So 2 counts, or even 20 counts as you probably meant to write, is not bad at all.

Full scale is not the problem. The bottom of the scale might be.
Try measuring 600mV for example. If the difference is still 2 counts, the meter could easily fall outside of its 1 year calibration.

[evava]

Wow! 2 counts is huge. Accuracy is supposed to be 0.05%+2 in the 5V range.

Unless I am mistaken, 0,05% of 5.00000V is 0.00250V, i.e. 250 counts in 500,000 count mode.
So 2 counts, or even 20 counts as you probably meant to write, is not bad at all.

I think accuracy is valid for 50.000 count mode only.
No accuracy is specified for 500.000 count mode.
http://3me.rs/PDFs/multimetri/BM860%20Uputstvo.pdf

[joeqsmith]

Do you just want to see how much mine change?   My guess is meters like the my free one don't change.  They just can't read down low enough to detect the offset.   Better meters like my Bymen and Gossen, I expect would shift the most counts.  The TPI, UNI-T and CEM I would expect to shift less (less digits). 

Or are you just wanting to know going forward if I can show this as part of the testing?

I wonder mainly about UT181a and of course upcoming GW121.
And as part of your future testing it would be nice to know more about meters.

I know now that 2 counts difference is probably normal and common, but I would like if there was no count difference at all when interchanging the probes.

All meters are tied together to one start point then to the Fluke standard.  Shown with 10 and 1V.  As you would expect the Brymen and Gossen have the worse count change but again they do gain a digit.   I did not run the free Harbor Freight meter but hard to believe meters like that would detect anything. 

I did not run the 121GW because I am attempting to run a different test with it.   One thing to keep in mind with that meter is first, it's not in production.  Anything I show with the meter may not represent how the final product behaves.   Another is that because that meter can measure power, there may be more test cases you want to run.  And finally, I did damage the meter which may also play into it. 

Also,  I should mention that the Gossen is no longer factory stock.  It does have those Netic and copper shields installed to help stabilize it.   Of course, the UNI-T is also highly modified to get the thing to survive the grill starter.  The Brymen was damaged during testing and I had to repair it, so it too is not factory fresh.  The TPI is damaged with the controller IC appearing to have one or more pins with high leakage currents.   The CEM was also damaged during testing and needed to be repaired.  Just keep in mind that the meters as shipped from the factory may behave differently. 

[ebastler]

Unless I am mistaken, 0,05% of 5.00000V is 0.00250V, i.e. 250 counts in 500,000 count mode.
So 2 counts, or even 20 counts as you probably meant to write, is not bad at all.

Full scale is not the problem. The bottom of the scale might be.
Try measuring 600mV for example. If the difference is still 2 counts, the meter could easily fall outside of its 1 year calibration.

But why would you assume that the deviation (upon changing polarity of the input signal) stays at the same absolute magnitude when you apply a much smaller input voltage? I would expect it to be smaller, largely in proportion to the applied voltage. I am pretty confident that at 0V input signal, the effect of reversing polarity will be zero. 

[Wytnucls]

Unless I am mistaken, 0,05% of 5.00000V is 0.00250V, i.e. 250 counts in 500,000 count mode.
So 2 counts, or even 20 counts as you probably meant to write, is not bad at all.

Full scale is not the problem. The bottom of the scale might be.
Try measuring 600mV for example. If the difference is still 2 counts, the meter could easily fall outside of its 1 year calibration.

But why would you assume that the deviation (upon changing polarity of the input signal) stays at the same absolute magnitude when you apply a much smaller input voltage? I would expect it to be smaller, largely in proportion to the applied voltage. I am pretty confident that at 0V input signal, the effect of reversing polarity will be zero. 

Why do you assume the relationship is linear? It might not be. A simple test would put the matter to rest.