An automatic sprinkler normally set to operate at 212°F, 286°F, or 360°F, for solder-type sprinklers and somewhat lower temperatures for nonsolder types. See: High Temperature Heads
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}