Abstract: A fire alarm and heat detection system and apparatus employs a thermoplastic film tape, of a plastic material which may or may not be heat shrinkable, e.g., polyvinyl chloride, polyethylene, polypropylene, rubber hydrochloride, polyvinylidene chloride, polyester, or nylon, having a substantial drop in tensil strength at a predetermined temperature. A conductor wire is supported on and extends for the entire length of the tape. The wire may be round in cross section or a flat foil and embedded in the tape or formed of two separate film tapes, heat sealed or adhesively laminated together or supported, by printing or the like, on the surface of a single tape. The tape and wire are supported across a supporting frame or yoke having supporting members spring loaded apart to apply a predetermined tension which may be preselected whereby the tape and wire will break on occurrence of a predetermined temperature.

Abstract: A fire alarm system and method utilizes a heat-shrinkable material, such as a sheet of polyethylene plastic film, to break a thin foil conductor attached thereto and thereby activate an alarm.