How to make your headcap ?
You can choose whether BioSemi assembles your headcap or that you assemble your headcap yourself. Some users prefer the last because it allows them to install the electrode at exactly the spots relevant to their application. The holders can always be relocated afterwards. Of course, if you do this very often, more and more holes will eventually force you to buy a new empty headcap. Headcap's are supplied with a sticker labelsheet with 10/20 labeling or the BioSemi ABC labeling.

A headcap with 64 electrode channels consists of:

66 x Gel-Cavities
66 x Fasteners
66 x X-rings
Note: Each headcap needs 2 extra electrode holders for the "Common Mode Sense" and the "Driven Right Leg" electrodes. These 2 electrodes are not normal electrode channels, but are needed for driving the subject towards the Voltage of the AD-box and for suppressing the Common Mode induced by for example main power equipment in the neighborhood of subject.

Insert the X-ring in the Cavity
Place the Cavity at the bottom, right in the middle of a dot.
Press and Rotate your thumb over the headcap in order to press the 8 pins of the Cavity through the cap.
Check if the dot is still in the middle of the headcap
Press the Fastener FIRMLY on the Cavity
Use a solder iron at 300 degrees Celsius for making a hole in the headcap. The best way is to press the solder iron all the way down quick and also pull it out again quick. The X-ring will not be melted quickly as long as it will not touch the solder iron longer than 3 seconds.