We have encountered a problem while using the Biosemi system in our lab. We have 2 systems in 2 separate rooms (Faraday cages). In one of the rooms (room #1 from now on) we started receiving a very noisy signal (see picture 1 below) which didn't improve after cleaning and adding more gel to the CMS-DRL electrodes.
- Picture 1- noise
- picture1.jpg (82.68 KiB) Viewed 12123 times
• We tried switching to a different set of electrodes. in room#1 we received the noise we described. We used the exact set of electrodes in room#2, and the noise disappeared (see picture 2). We did this with another set of electrodes- with the same results.
Conclusion: It's not a problem with a specific electrodes set.
- Picture 2- no noise
- picture2.jpg (69.35 KiB) Viewed 12123 times
Conclusion: it's not the AD-box
• We tried switching the receiver between the rooms. We used the receiver from room#2 and put it in room#1- the signal was still noisy. Next, we used the receiver from room #1 in room #2- the signal was clear, there was no unusual noise.
Conclusion: it's not the receiver
• We did the same thing with the optical fiber, the presentation cable and the USB cable connecting the receiver to the computer.
Conclusion: it's not a cable problem
Importantly, there was no new equipment in the rooms or in the lab area, there wasn't any external change that we know of. We tried disconnecting all unnecessary electrical equipment in the lab, there was no change.
We ran out of ideas of what the cause of the problem might be. We will appreciate any help\ideas. Thank you!