chris collister Mar 12, 2012:

I have used many USB data acquisition devices in the past, though the only ones which might qualify as a "clé" have been self-contained temperature and humidity sensors. It might be best to play safe and refer to it as a "data acquisition device". The MyChron website deals specifically with Karting, and the "compteur" seems to measure rpm, temperatures (various) and speed, but see also http://renneskart.fr/mychron.aspx