Noise even when all electrodes disconnected

Started by martin1263, February 14, 2016, 08:56:56 pm

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martin1263

February 14, 2016, 08:56:56 pm Last Edit: February 14, 2016, 09:00:55 pm by martin1263
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.

research

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

 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

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

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....