Electro-Gel conductive gel for EEG caps

A cap gel is not an ordinary electrode gel. It has to pass through the opening of the integrated electrode, travel through the hair down to the scalp, and stop there. Too fluid and it spreads under the cap and creates a salt bridge between two neighbouring positions: two channels showing the same signal, and a montage to redo.

Electro-Gel is calibrated for that constraint. It is made by Electro-Cap, the very house whose caps gave the category its generic name, and the gel was designed with the caps, not adapted to them afterwards.

It is injected with a blunt-tip syringe, the one used to work through hair without injuring the scalp. Half a millilitre per electrode is usually enough; the reflex to add more is the leading cause of bridges.

The three volumes answer three service rhythms. The 473 ml bottle suits a lab fitting a few caps a week. The 3.8 litre container is for departments running back to back, and it costs appreciably less per millilitre, provided the turnover follows: opened gel does not keep indefinitely.

At take-down it rinses out with warm water, cap and hair alike. It leaves no sticky residue and does not attack the tin electrodes of the caps.