Dave, you say in the video the BM857A is rebadged as Extech MM570A but it is actually rebadged as Extech MM560A. The Brymen BM859CFa is one with 2 temperature readings like BM869 and is rebadged as MM570A
Did anyone understood anything from what I wrote? Because, I am getting dizzy with all these numbers...
Dave, you say in the video the BM857A is rebadged as Extech MM570A but it is actually rebadged as Extech MM560A. The Brymen BM859CFa is one with 2 temperature readings like BM869 and is rebadged as MM570A
Yes, I stand corrected. The BM857A is sold as an Extech MM560A
Dave.
Nope, it does not
Spawn, I guess Extech goofed up... The Brymen has one millimeter clearance (I hope the picture is clear).
Obviously this clearance may mean nothing depending on the height of the fall (and the compression of the rubber jacket).
** I just saw that last post about the IR serial adapter. I don't think that adapter is compatible with the 857. That one has a long tab that fits in a slot in the BM25X meters. The adapter for the 857 is shorter and has two wings that rotate into the housing on the meter. I bet it would work, but it would take a lot of duct tape.
Can't tell from the pic if the cable has groves on the outside edges (thin ends) or not to fit the "wings" on the back of the BM857 (I have one). Figured from a systems POV, they'd try to use a single interface cable for all of their models, but can't tell for sure.
A few things missing on the mini-review; the 85x has two "OFF" positions: one on each side of the rotary switch, which is somewhat convenient.
But if you're not accustomed to 2 OFF positions like me, it won't matter. I always end up turning it counter-clockwise to turn it OFF.
A DMM fuse change is a once in a lifetime event--
Yeah, I get that. My guess would be that the 9V "battery at the end of the meter" design limits the options for rear panel access.
Hell, what do I know? My only DMM is a Radio Shack 22-168a that I bought in HS in the mid 90's.
Dave, you have REC and CREST modes for MinMax. Rec is regular MinMax while Crest they use for Peak detection (faster update speed, its like Peak on Fluke 87V).
Limitation for Brymen BM257 are:
Capacity only up to 3000uF
Diode range only up to 1.000V
While scanning posts, I remembered that Kiriakos had mentioned that the Sanwa PC7000 used the same PC connector as the Brymen. Perhaps Sanwa is another Brymen re-badge/re-case.
As far as dropping a multmeter face down, everyone seems to forget that the leads will most likely be attached an they will hit before the dial does.
@ All Indians ,
I Have figured out how to sell these in india .Lets see what all models we have here would take a weeks time frame to get more info .
Elma BM869
Looks like they want 50% more for the Elma name.....
But you get a nice green rubber jacket instead of the red one...
DKK 2075 + 25% Danish VAT = DKK 2593.75 (~€350) plus shipping from elma.dk.
I paid €224.69 plus shipping from TME for my Brymen BM869 a year ago, so yeah, that green jacket is expensive.
While scanning posts, I remembered that Kiriakos had mentioned that the Sanwa PC7000 used the same PC connector as the Brymen. Perhaps Sanwa is another Brymen re-badge/re-case.
As far as dropping a multmeter face down, everyone seems to forget that the leads will most likely be attached an they will hit before the dial does.
I wouldn't think so, the sanwa PC7000 is orange backlight and it's rather old now and has a slightly different layout.
Copy maybe? I know mostly Sanwa makes their own stuff
Elma BM869
Urgh, the neon green jacket is awful. It makes the BM86* look very ricer-ish
Why can't more meters have built in charging using the current jack like the Agilent ones?
Urgh, the neon green jacket is awful.
It is, eh, different.
(I am not sure it is neon green. It could just be the lighting.)
I've got the same meter as the MB857A except its branded as the AMPROBE AM-270.
Backlight is crappy as shown but cost me US$80.00.
Actually the AM-270 is a re-cased and re-branded BM815.
Hey, how does the 500000 count work with the accuracy and voltage ranges ?
The specs say "DC voltage measuring range - 0,01m...500m/5/50/500/1000V" and "DC voltage measuring accuracy - ±(0,02% + 2 digits)"
For example, if I measure a LiPo cell that is exactly 4.2 volts, what does the meter say ?
This is how I see it, but I'm not that sure myself:
Voltage is under 5V, so I get "4.<decimals>".
Accuracy is "±0.02%", so error there is 0.00084V.
The +2 counts means the last digit can be smaller or bigger by 2.
500000 count means the first number can be between 0 and 5 (maybe 0-4?), with total of 6 numbers on the screen.
So TL;DR:
On the BM869, would a spot on 4.2V measure as something between 4.20086 and 4,19914V ?
I can't find it in the datasheet, but I would expect the accuracy specs to be for 50k counts mode, so the offset uncertainty would be +/- 20d in 500k counts mode. This is typical for handhelds (the Fluke 87V does the same), and +2d sounds very optimistic for a 500k count meter.
Alm got it right. Accuracy is no better in 500,000 count mode. The only benefit is an increase in resolution.
Hmmh...
Is the accuracy and count difference constant, or do they change ?
So if I have two 4.2V cells, can the other say 4.20104 (+0.02% +20d), and then right after the other says 4,19896V (-0.02% -20d).
Or is it so that with 4.2V, it always shows +0.015% and -9d, at least until the calibration drifts over time ?
You can usually expect short term stability to be much better than long term stability. So two cells measured as 4.20104 V within five minutes from each other are likely much closer than +/- 0.02% +/- 20d. You can usually also expect a cell that measures 4.20114 V to have a higher voltage than one measured 4.20104 V (ADCs in DMMs are often monotonic).
I wouldn't extend this to assume that the deviation will be constant across its entire ADC range, this will also depend on properties like linearity, which are not necessarily guaranteed.
Hmmh...
Is the accuracy and count difference constant, or do they change ?
So if I have two 4.2V cells, can the other say 4.20104 (+0.02% +20d), and then right after the other says 4,19896V (-0.02% -20d).
Or is it so that with 4.2V, it always shows +0.015% and -9d, at least until the calibration drifts over time ?
That would be answered by the stability and repeatbility of the reading. How many digits of bobble is there and what is the scatter of multiple tests of the same voltage over a short time span. At high resolutions if you dont have some form of averaging there can be a lot of bobble of the least significant digits. IMO unless a meter is real junk the error amount and direction will be consistent other than long term drift.
Edit: Sorry Alm, you type faster than me.
Hmmh...
Is the accuracy and count difference constant, or do they change ?
So if I have two 4.2V cells, can the other say 4.20104 (+0.02% +20d), and then right after the other says 4,19896V (-0.02% -20d).
Or is it so that with 4.2V, it always shows +0.015% and -9d, at least until the calibration drifts over time ?
In my experience, most meters read exactly the same from one minute to the next, and from one day to the next. Readings can drift over weeks and months, and will vary with temperature. Once you get down to the sub-mV digits they will also jump around due to ambient electric fields, thermal effects, and the test leads acting like antennas.
For example, here is a picture I took about one year ago:
Here is the same meter reading the same voltage source today:
There has been some change as you can see. I didn't control the temperature, so some difference might be due to the room temperature being different. The rest would be accounted for by drift in the meter or drift in the voltage reference.
When it comes to reading digital measurement results, my way.. (probably a lot of others as well) .. always ignore the least significant digit, then your life will be happier and your nerves will be more relax.
Also try to train and develop the mental for ignoring the last digit, that will help too.