EEVblog 121GW Multimeter Issues

[stuartmp]

You can try a zero offset callibration for that range as described in the manual . I did that myself for current offsets ( obvious not that bad that yours )

Ok so I can do a offset calibration without affecting my range calibration?

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[CDaniel]

Yes you can and it's simple .

[stuartmp]

Yes you can and it's simple .

Ok. So its fixed but I didn't do anything besides steps 1 to 5 from page 65. Turning it on from the 3 o'clock position anti clockwise to the A / mA position. When I pressed the Rel button I noticed that the offset went back to zero. So I thought I wonder if this did anything. So I  just turned it off and back on again and it was fine back to zero. Very strange.



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[CDaniel]

Who knows what firmware or calibration bug you had , good that now it is ok .

Anyway for everyone who has some current offset ... the latest firmware it seems to do a better job zeroing the offset  . Before I couldn't do it so good .

[stuartmp]

Who knows what firmware or calibration bug you had , good that now it is ok

One other thing that I noticed was that in mVA/VA mode the Range scale indicator does not change it just says '5' in the bottom right corner not matter what range you select. Is this normal?

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[CDaniel]

That is a bug that now I see ... the range number stay in the last used range on the other functions , so if it was 50 or 500 in current mode and you switch to VA it will show 50 or 500 and so on  . The default is 5 if you turn it fast from OFF to VA and doesn't have time to settle anywhere

[stuartmp]

That is a bug that now I see ... the range stay in the last used range on the other functions , so if it was 50 or 500 in current mode and you switch to VA it will show 50 or 500 and so on  . The default is 5 if you turn it fast from OFF to VA and doesn't have time to settle anywhere

So how does the bug get reported and fixed in a future firmware update.

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[CDaniel]

Maybe someone read this thread , or you can report directly at https://www.eevblog.com/product/121gw/ you have there "Report an Issue" . I did that a number of times .

[e0ne199]

has anyone noticed this?
try to turn burden voltage on, set the 121GW to 10A range and measure load current without using its voltage probe
mine on 10A range, the current reading drops about 2mA when the burden voltage is on, but when i turn the burden voltage off, the current reading on 10A range is back to normal again (without 2mA drop)...
no problems with burden voltage turned on or off when i set the meter to 5A or 500mA range

is this a bug or something? please respond, thx

I don't see this particular issue clearly , but may be explicable ... with the voltage probe inserted and burden turn on  is picking up the electrical field noise which somehow interfere with the current reading . So when I touched the voltage probe tip from 930mA the reading went to 990mA . Pretty insane .
Even that non zero current offset when you don't measure anything changes when you put the hands near the terminals ...

actually it happens only on 10A range, on the other range it looks normal...
that 2mA drop is really pain in my eyes anyway 

[CDaniel]

May be an issue but I don't see it ...

[e0ne199]

May be an issue but I don't see it ...

looks like it is only my problem...what firmware version do you use?
on me sometimes the bargraph flashes and after that the meter shows correct value...but about one second after that the value drops 2mA again...i hope this is just a software issue anyway

[CDaniel]

V2.00 and the bargraph flashes sometimes

[kf4hzu]

So I’ve posted before about this but the Bluetooth radio in my meter isn’t working. My buddy’s meter will connect instantly but mine will not. Using a Bluetooth scanner does not detect the meter at all. This leads me to believe the radio is not functioning. Anyone else have this issue?

Are you trying to connect / find both meters from the same device? Have you tried several different devices (phone, PC, tablet)? What distance is your meter at from the device? What firmware version are both meters running?

[uer166]

The banana socket tips on my meter broke off with normal use, nothing was forced. I used Pomona banana cables inserted into meter. NBD for functionality, but it's a brand new meter and doesn't feel great..

[Terry01]

How did you manage to break both Current jacks? That sucks buddy 

[uer166]

Again they just fell off after normal use, no yanking or force. In fact the 10A jack broke after one single careful insertion of the banana jack 

[Brumby]

I don't think I've heard of that before - and I'm puzzled as to how it could have happened (... and I'm not just talking about the 121GW).

[joeqsmith]

I cracked one on the prototype but take full blame as I frequently used non shrouded leads with it.   I'm not too concerned about it and assume they used a different material for the released meters that would make them more robust.   

I'm surprised to see them sheared off like this.   With non shrouded leads installed, if it were dropped maybe it could cause it.   

[uer166]

Can confirm they were non-shrouded leads. Can also confirm meter was never dropped and leads were not yanked... Unless someone else at the lab did it of course.

[Electrowiz]

U2.00 Firmware has a minuscule bug to report. I have been working with thermocouples, as of late. Working with a Temperature calibrator, I needed to change the setting to Deg C to match the calibrator.

I pushed and held the SETUP button, until the top temp indicator began to flash. Then pushed the Up/Down arrow, which toggled the temperature scale from Deg F to Deg C. I continued taking readings and recording the results. After 2 minutes the temperature scale reverted back to Deg F except the main indication still read Deg. C. However the indication was clearly back to Deg F scale. (See attachment)

I obviously did not confirm the scale change, thus causing the display scale mismatch.

[bicycleguy]

@Electrowiz
I can confirm the problem you saw as a minuscule operator/meter error    If you forget to press and hold the setup button again after changing to F/C, then it will mess up as you described.

[graybeard]

What is the size limit (if any) for the micro SD card in a 121GW?  I can't find anything in the manual about it.

[jchw4]

Hello from another happy owner of 121GW (2.00)!

User manual does not say much about SD card logging, but it has a few caveats:

1) Autoranging does not work when logging is on. ("Auto" is still displayed though.)
DMM will log "-Overflow" and "Overflow" instead of switching ranges.

2) In "In 0" mode logging intervals are not even. DMM visibly stops every 5-10 (haven't calculated yet) values. I would assume it flushes data to SD card.
On average it still reaches ~4.77 records per second.

3) It's possible to make it totally stop for several seconds (like 10) by starting and stopping logging. I would assume it is the same SD card data flushing.

If these are features not bugs, please update the manual.

[dr.diesel]

I've got two of these, updating the 1st went without an issue (just like all the other times I've done this), #2 locked up during the v2.0 update.  After about 10 minutes of just letting it be I finally switched it off and back on:

 

Also note, the MEM and HOLD buttons no longer respond on power up.

[EEVblog]

I've got two of these, updating the 1st went without an issue (just like all the other times I've done this), #2 locked up during the v2.0 update.  After about 10 minutes of just letting it be I finally switched it off and back on:
 
Also note, the MEM and HOLD buttons no longer respond on power up.

That's a first. No other reports of that, and I've tried pulling the SD card during the update and other stuff to abuse it and the bootloader recovers fine.
Are the batteries ok?