Avoiding corrosion of electrodes

[bburt]

We typically use a plastic syringe with stainless steel, disposable, blunt needles to apply gel. Recently a new user of our BioSemi system commented that she believed that using a metal needle could cause damage to the electrodes (presumably meaning during application of gel to the flat, EMG electrodes). It was the first time I'd encountered this concern, and I've not seen anything about it in the Operating Guidelines or the User's Manual.

Is this a concern other users have encountered?

[Coen]

The Ag-AgCl pellets should not be contaminated with non-silver metal particles, since this will cause low-frequency noise (approximately below 1 Hz). We supply plastic tipped needles for this reason.

Using a stainless needle increases the danger of polluting the silver and silverchloride with tiny amounts of nickle, iron and chrome.

Best regards, Coen (BioSemi)