Minerva MR601TEX Conventional Intrinsically Safe Fire Optical Smoke Detector combines optical and heat detector technology to detect clear burning fire products which hitherto could only be easily detected by ion-chamber detectors. For normal ambient conditions, the high-performance optical detector behaves like a normal optical detector. Only when a rapid rise in temperature is detected does the sensitivity of the detector increase and the presence of smoke will confirm a fire condition which will be transmitted as an alarming level.