Each type of Flame Detector can detector a flame from any source apart from Magnesium and Sulphar which can be detected with special versions of the Flame Detectors. The Flame Detectors have a Fire and a Fault relay and need a flickering flame to activate.
IR2: This Flame Detector is for inside use only and where the fastest detection is required. It can be used through glass but note there will be a small drop off in the range of the Flame Detector. It is available in IS and ExD versions.
IR3: This Flame Detector can be used inside or outside and is the best choice for a dirty environment. If it is being used outside, care should be taken that the sun does not shine on the Flame Detector as this can cause false alarms. Again, the IR3 can be used through windows, but there is a small drop in range. The IR3 is also available in IS and ExD versions.
UV/IR2: This Flame Detector is the best choice for being used outside as it can be used in sun light (care must be taken to ensure the sun does not flicker on the Flame Detector) and has the highest immunity to false alarms as it needs both IR and UV to activate. The UV/IR2 cannot be used through windows and is available in an ExD version.