I believe the purpose is to give the user as many false alarms as possible.
temperamental little buggers
I love AC, but to be honest, to me that one is the most gimmicky device of the whole catalog. If you're not all thumbs, you shouldn't need it ever. but there's nothing wrong making a buck or two to sell peace of mind :p
Regardless of how well it works, i personally am not fond of a device that is designed to vent my coolant all year long.