Handheld meter robustness testing

[Wytnucls]

I've never seen a Gossen meter with a metal shield on the back. Most have a plastic cover secured with one screw to the PCB. (The old models at least)
I checked the one fitted on the 30M. It doesn't seem to be conductive, unless there is perhaps an internal metallic layer.



https://www.eevblog.com/forum/testgear/adjustment-of-metrahit-18s-and-18c/?action=dlattach;attach=156669;image

This PRO model has 2 shields, but they might both go in the front of the PCB:



https://www.eevblog.com/forum/repair/metrahit-pro-leaked-battery-repair-attempt/?action=dlattach;attach=275276;image

[Fungus]

$800, 6-digit meter with no internal shielding at all?

Here I thought nothing got by you. There is a shield on one side of the board.

I wrote that just after you took the back off, a few minutes into the video. I was expecting full internal shielding on a meter of that class. Front and back, either on the inside of the case or a fitted metal shield like the one you made.

[joeqsmith]

I've never seen a Gossen meter with a metal shield on the back. Most have a plastic cover secured with one screw to the PCB. (The old models at least)
I checked the one fitted on the 30M. It doesn't seem to be conductive, unless there is perhaps an internal metallic layer.



https://www.eevblog.com/forum/testgear/adjustment-of-metrahit-18s-and-18c/?action=dlattach;attach=156669;image

This PRO model has 2 shields, but they might both go in the front of the PCB:



https://www.eevblog.com/forum/repair/metrahit-pro-leaked-battery-repair-attempt/?action=dlattach;attach=275276;image

I'm curious now if there is a shield under that plastic cover in the first picture. 

The second picture looks like the shields shown on Dave's Xtra.  Makes sense they would keep them all the same.  Maybe they felt it was not worth the cost to tool one for the BT model.   

Also it makes me wonder if the Energy is sensitive to static like the Ultra.  They appear to use a different relay.  Maybe it does not have the same sensitivity.   

[The Soulman]

I'm curious now if there is a shield under that plastic cover in the first picture. 

The second picture looks like the shields shown on Dave's Xtra.  Makes sense they would keep them all the same.  Maybe they felt it was not worth the cost to tool one for the BT model.   

My metrahit 2+ appears to have the exact same shield as in the first photo and it hasn't a second shield underneath it, it must be some special plastics.

Always wondered what those randomly placed holes where for, now I know. 

Edit: after 1 minute of google I've found this material:
https://www.rtpcompany.com/products/emi-shielding/
The shield/cover is probably made out of something like that.

[chronos42]

   

Also it makes me wonder if the Energy is sensitive to static like the Ultra.  They appear to use a different relay.  Maybe it does not have the same sensitivity.   

Hi,

no, my Energy has no Problems with static discharging in all ranges.
It also has only one metal shield on the backside, at the topside is a plugin board with the power measurment processor.
It contains two Relais, not sure if this are the same type or not. (I assume they are different)

I was not able to trigger the relays with a magnet or a degausing coil,  my magnet and the coil seems too weak for this.

But I did check this:

Switch the meter on and then set it from the V mode to resistor mode, one of the relais clicks.
Then I switched off the meter, set in the V mode and turned it on again. The relais was set back to the correct state, it worked as expected. (Firmware rev. is 1.20)

Regards

[MacMeter]

$800, 6-digit meter with no internal shielding at all?

 

Here I thought nothing got by you. There is a shield on one side of the board.  If you watch Dave's video of the Xtra, you will see the same 4 PTHs where the second shield mounts to.   That shield does not look like it would have worked for the Ultra BT.   

The questions I have is does the A model (no BT) have a shield on the backside and is my B model missing a shield from the factory or was this by design?   Because Gossen has had no contact with me and Dranetz went so far as to block my email over a simple question of getting the meter aligned, I doubt I will ever know.

My email address is fresh (unblocked), if you like I'll send "them", a single message with a link to this thread. You can PM me with their contact info, up to you, not much to lose at this point if you've somehow been blocked, which is really odd.

[mzacharias]

I wonder if there might be a drop-in,  ground-shielded version of this relay. It might be possible to retrofit affected models.

Or alternatively, a firmware fix so the relay is at least pulsed at turn-on? This seems doable.

Pardon me if this has been suggested - I've been following the thread but could have missed something.

[The Soulman]

Or construct a alternative blue-tooth module with a large ground plane?

[joeqsmith]

Second post about the need for a grounded shield on the relay.      My concern with the relay is preventing a state change from an outside low frequency magnetic force like I show in the videos.

My email address is fresh (unblocked), if you like I'll send "them", a single message with a link to this thread. You can PM me with their contact info, up to you, not much to lose at this point if you've somehow been blocked, which is really odd.

I did create a playlist if you wanted to link that as well. 

I used the following two addresses: 
http://www.gossenmetrawattusa.com/contact/index.html

https://www.gossenmetrawatt.com/english/seiten/servicecentersupport.htm

   

Also it makes me wonder if the Energy is sensitive to static like the Ultra.  They appear to use a different relay.  Maybe it does not have the same sensitivity.   

Hi,

no, my Energy has no Problems with static discharging in all ranges.
It also has only one metal shield on the backside, at the topside is a plugin board with the power measurment processor.
It contains two Relais, not sure if this are the same type or not. (I assume they are different)

I was not able to trigger the relays with a magnet or a degausing coil,  my magnet and the coil seems too weak for this.

But I did check this:

Switch the meter on and then set it from the V mode to resistor mode, one of the relais clicks.
Then I switched off the meter, set in the V mode and turned it on again. The relais was set back to the correct state, it worked as expected. (Firmware rev. is 1.20)

Regards

Thanks for checking.  The Ultra can also detect the rotary switch change and cycle the relay if it was done during a power down.  This meter is using 1.23.  No idea if they use the same firmware for all the Metrahit meters. 

[IanB]

Second post about the need for a grounded shield on the relay.      

Apparently some people think a grounded shield will block magnetic fields... 

[tautech]

Dave's ghost meter is watching the surgery, knowing one day it will be his turn.   

And that day is getting closer. 

https://youtu.be/h4kxdhxDcq0

[joeqsmith]

I like the case.  It looks sharp with the zipper.  Lots of detail.  Of course, in the end, all that fluff won't help it survive the grill starter.  Looking forward to seeing just how robust this little beast is compared with all the other meters I have looked at. 

[sleemanj]

Apparently some people think a grounded shield will block magnetic fields... 

Well to be fair it's an easy error in thought to make.

To those playing along, the type of metal surrounding the relay is what is important for the magnetic concern, not where it's connected to.  Mu-Metal, as joeqsmith used in his can is what's needed - https://en.wikipedia.org/wiki/Mu-metal#Magnetic_shielding

Magnetically shielded relays (essentially, relays with a mu-metal shield pre-fitted over the top) are available.

[P90]

I like the case.  It looks sharp with the zipper.  Lots of detail.  Of course, in the end, all that fluff won't help it survive the grill starter.  Looking forward to seeing just how robust this little beast is compared with all the other meters I have looked at.

Would that be your famous  "pee-zee-oh" grill starter?   

[Wytnucls]

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[P90]

Protected yourself and your pacemaker from evil magnetic holders:
$65.95 only!
50% reduction of AC and DC magnetic fields!

[Lightages]

Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.

[P90]

Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.

you have seen the wrong things and been misinformed by the whitch hunters...

[The Soulman]

Second post about the need for a grounded shield on the relay.      

Apparently some people think a grounded shield will block magnetic fields... 

No, but it will help to reduce the "theremin" effect.

[3db]

Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.

you have seen the wrong things and been misinformed by the whitch hunters...

What bullshit ?
Who in their right mind would use a two coil relay and NOT ensure is was set to a defined state at power-up.  :
What about the shielding ?
It is what it is. Do you think Joe made it up ?

Gossen have messed up END OF STORY.

Their lack of response to Joe's communication is also arrogant and  RUDE.

Don't be such a fan boy !!

3DB

[lem_ix]

Thanks for the videos Joe As for Gossen, they've lost all credibility with this as far as I'm concerned. At that price point I expect the meter to be beyond rock solid.

[joeqsmith]

Second post about the need for a grounded shield on the relay.      

Apparently some people think a grounded shield will block magnetic fields... 

No, but it will help to reduce the "theremin" effect.

Not around the relay it won't.  The proximity effect was diminished with just the aluminum foil wrapped around the outside case.  The shield serves more than one purpose. 

[Wytnucls]

These are high count very specialized CAT III 600V only meters, with detailed calibration certificates.
Can they be made safer? Possibly, like most other meters. They do come though, with independent testing and meet current regulations.
There is always a premium on price when products are made in Europe and this one also comes with a meaningful 3-year warranty.
As for neodymium susceptibility, it is not very difficult to keep magnets at a safe distance and forego the use of magnetic holders.
It is a small price to pay, as nobody else yet makes a true 300,000 or 1,200,000 count portable meter and may never do.
So, enjoy them while you can, before they disappear completely, under pressure from Asian products.

[joeqsmith]

These are high count very specialized CAT III 600V only meters, with detailed calibration certificates.
Can they be made safer? Possibly, like most other meters. They do come though, with independent testing and meet current regulations.
There is always a premium on price when products are made in Europe and this one also comes with a meaningful 3-year warranty.
As for neodymium susceptibility, it is not very difficult to keep magnets at a safe distance and forego the use of magnetic holders.
It is a small price to pay, as nobody else yet makes a true 300,000 or 1,200,000 count portable meter and may never do.
So, enjoy them while you can, before they disappear completely, under pressure from Asian products.

I'm enjoying it all right.  Next part, we will see just how robust that front end is.   

I doubt the average person would take the time to see if a magnetic strap would effect their new high count, very specialized CAT III 600V only meters, with detailed calibration certificates.   I personally would have never thought they would release such a product. 

[joeqsmith]

Everything I have ever seen about Gossen just makes me think "Overpriced bullshit". These videos have not done anything to sway me from this at all.

It may be interesting to look at one of their low end meters.   Personally, for a low count meter with some basic features, I still like Dave's rebranded Brymen.  Seems well made and certainly held up to my testing.