Bucket Test Interpretation

[Parabelo]

We have done the ONE bucket test to our electrodes and the results came as described below:

1. When we put both the CMS and DRL (only) electrodes in the water the blue light will came on consistently.

2. Maintaining CMS +DRL in the water, once we add any other active electrode the blue light STAYS on. It actually STAYS ON whether or not we put any active electrode in the water bucket.

If this is the correct test procedure, how do we test faulty galvanic connections in the active cables, such as broken wires?

Thanks

[Coen]

A continuous blue light means that all electrodes in the water are functioning properly. The blue light blinks when one or more electrodes in the water have broken wires.

With all the electrodes in the water, check that the signal output by wiggling the electrodes in the water, you should see the related baseline drift for each electrode on screen.

Offsets should be stable and within approx -50 mV and + 50 mV.

Noise should be in the 5-10 uVpp range with a 1 Hz high-pass and 100 Hz low-pass applied (referenced to the average of all electrodes)

Best regards, Coen (BioSemi)

[Parabelo]

Coen wrote:
> A continuous blue light means that all electrodes in the water are
> functioning properly.

Ok, I think this statement is not 100% correct acording to my tests, since a continuous blue light is achieved by simply immersing the CMS and the DRL electrodes in the salt water, without any other electrodes there.


>The blue light blinks when one or more electrodes in
> the water have broken wires.

Also not quite so, since if you immerse an electrode that has been disconnected from the AD box, thus effectively simulating two broken wires, the continuous light blue light still keeps on!


> With all the electrodes in the water, check that the signal output by
> wiggling the electrodes in the water, you should see the related baseline
> drift for each electrode on screen.

So you are stating that the only way to effectively check out complete galvanic connection between the electrodes and the AD box is via wiggling the electrodes in the water and observing a related baseline variation?

[Coen]

Trolls will be blocked from the forum

[rtrato]

Hello everyone.

I dont think this a Troll situation, since I also experienced the same behaviour.

With only EX1 connected, the blue light is on.
If I disconnect EX1, the blue light stay on.

Can you please be more specific with you answer?
Shouldnt it started to blink?


Thank you.

[Coen]

With CMS and DRL in the water the blue LED is on.

When EX is put in the water and is working correctly, the Blue LED stays on; when EX is defect, the blue LED starts blinking.

with EX out of the water or disconnected it obviously cannot affect the status of the blue LED, so what is your problem ?

[rtrato]

Thank you for your answer.

I would like to point that:
a) Both wires defective
b) Unconnected sensor
cannot properly be handled by a bucket test.

If you have something to add and improve the accuracy of the above statements,
we will be glad to know.

Once again, thank you very much.

- - -

Merci bien de votre réponse.

Je tiens à souligner que:
a) Les deux fils défectueux
b) Capteur non connecté
ne saurait être correctement traité par un test de seau.

Si vous avez quelque chose à ajouter et améliorer la précision des déclarations ci-dessus,
nous serons heureux de le savoir.

Encore une fois, je vous remercie beaucoup.

[Coen]

If both wires are not connected then the particular channel will not show an offset between -50 mV and +50 mV (offset will be at the negative maximum) with the electrode in the bucket, and wiggling the electrode in the water will not give any reaction on the channel trace (trace will be a flat line). These two outcomes were clearly pointed out in my first answer above. So, the one-bucket test can very well be used to pinpoint an unconnected electrode.

Another troll ?

[rtrato]

Thank you