How does the EIII keyboard sense velocity?

[Emu276]

I cleaned a dirty key contact that was not triggering at all, and unfortunately tore the rubber cone with the conductive carbon dot & ring off. Fortunately I was able to carefully position it back with a couple drops of glue on the top side of the rubber (NOT the side touching the PCB!) and the key triggers perfectly. However, the velocity is always at maximum.

How is velocity sensed? Does it involve the conductive contact, or some other mechanism? I'd like to know before I do any more physical adjustments that might damage the rubber contact even further.

Thanks,
Howie