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Author Topic: Noise even when all electrodes disconnected  (Read 3166 times)

martin1263

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Noise even when all electrodes disconnected
« on: February 14, 2016, 08:56:56 PM »
Good evening,
 
I recently purchased EEG-SMT and four AE and one PE. And I would like an advice. I used laptop. Tried almost everything, like another PC, different location, switching cables, brainbay....

My setup:
https://imageshack.us/i/pmwzz6djp

This is what I get in with no cables attached, just EEG-SMT connected:
https://imageshack.us/i/pn5OWajHp

Only DRL connected no change:
https://imageshack.us/i/pl6TCGhTp

DRL holding firmly in my hand and second channel connected FP1 FP2(It reacted to taping the electrodes as you can see in the end)
https://imageshack.us/i/plp41fxTp

DRL holding firmly in my hand and first channel connected FP1 FP2
https://imageshack.us/i/plqGorZQp

When again I disconnected all the wires I get this:
https://imageshack.us/i/pnFLknp9p

Could you please help me with this pickle? Thank you in advance.
« Last Edit: February 14, 2016, 09:00:55 PM by martin1263 »

research

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Re: Noise even when all electrodes disconnected
« Reply #1 on: February 15, 2016, 11:17:53 AM »
Hi,

I suppose you unplugged your laptop and had it run on battery while measuring?
Thus avoiding power line noise.

With PEs I usually get better readings when everything is connected,
this might apply to PAs too.
for example:
chan+1 to fp1 and chan-1 to left mastoid (behind the ear) and
chan+2 to fp1 and chan-2 to left mastoid and
DLR attached to a forearm.

Good luck!

martin1263

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Re: Noise even when all electrodes disconnected
« Reply #2 on: February 15, 2016, 10:49:18 PM »
 I have laptop running on battery altough I have PC nearby and tried switching them and I get the same noise...

From reading this post(https://www.olimex.com/forum/index.php?topic=2248.0) second massage the main problem is that it should give straight line with no electrodes connected. It may be hardwere problem.

Could you explain the term PA?

Thanks.

research

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Re: Noise even when all electrodes disconnected
« Reply #3 on: February 16, 2016, 11:33:56 AM »
Oh, PA is a typo I ment to write AE (active electrode).

Just contact olimex-support (and/or your distributor) directly, if you suspect faulty hardware.
olimex-support is really very helpful.

martin1263

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Re: Noise even when all electrodes disconnected
« Reply #4 on: February 29, 2016, 05:34:43 PM »
Well they told me to send it to them and that they will check it. So hopefully they will find where the bone is buried....