Abstract: A moisture actuated trigger device comprising a housing; a moisture absorbing swelling body in said housing, one end of said body engaging a stationary wall of said housing and the opposite end engaging an end wall of a sleeve slidable within said housing upon expansion of the swelling body; an elongated plunger member in said housing movable between a first, stand-by position and a second, released position; latch means detachably engaging said plunger member for holding in its first, stand-by position; a spring means biasing said plunger member in a direction towards its released position, cam means on said sleeve for disengaging the latch means from the plunger member thereby enabling the latter to rapidly move from its first, stand-by position to its released position; and a shock wave initiating means located in the path of said plunger member and adapted to initiate a shock wave when struck by the plunger member.

Abstract: A detector for liquid media has a swelling body which in the presence of the liquid expands to break open an ampule of electrolyte solution under pressure, enclosed in a rubber sheath together with a dry-charged galvanic element. The electrolyte enters the galvanic element, which starts producing electric current, thereby signalling presence of liquid.