▁the ▁mel ting ▁point ▁ ▁( above ▁ 1 3 0 0   ° C ) ▁and ▁there ▁is ▁no ▁tw in ▁formation . ▁K ist ler ▁uses ▁the ▁C zo ch ral ski ▁process ▁( g row th ▁from ▁a ▁m elt ), ▁which ▁has ▁been ▁known ▁since ▁ 1 9 1 6 . ▁The ▁process ▁allows ▁large , ▁high - quality ▁cry st als ▁to ▁be ▁grown ▁within ▁a ▁relatively ▁short ▁period ▁of ▁time . ▁ ▁High - temper ature ▁and ▁ball istic ▁pressure ▁sens ors ▁ ▁K ist ler ▁meas uring ▁systems ▁allow ▁meas uring ▁therm o ac oust ics ▁phen omena ▁in ▁har sh ▁environments ▁with ▁extreme ▁temper atures ▁up ▁to ▁ 7 0 0   ° C . ▁App lications ▁include ▁monitoring ▁of ▁gas ▁tur b ines ▁and ▁other ▁tur b om ach in ery , ▁R & D ▁of ▁continuous ▁det on ation ▁engines , ▁monitoring , ▁and ▁control ▁of ▁pressure ▁oscill ations ▁in ▁pip es ▁and ▁ac oust ic ▁therm ometry . ▁K ist ler ’ s ▁dur able ▁pie zo elect ric ▁sens ors ▁based ▁on ▁propriet ary ▁Pie zo Star ® ▁K I 1 0 0 ▁cry stal ▁material ▁have ▁been ▁developed ▁specifically ▁for ▁temper atures ▁up ▁to ▁ 7 0 0   ° C . ▁K I 1 0 0 ▁cry st als ▁have ▁no ▁py ro elect ric ▁effect . ▁ ▁The ▁pie zo elect ric ▁sens ors ▁( named ▁" channel ▁sens ors ") ▁from ▁K ist ler ▁are ▁also ▁used