Spectrex 40/40I Triple IR (IR3) Flame Detector - Manual (Page 44)

SharpEye TM IR3 Flame Detector User Guide
32 Configuring your Detector
2.8.5 Heated Optics
The heated optics can be defined as one of the following modes:
 Heated Mode
 OFF: Not operated
 On: Continuously
 AUTO: Per temperature change
In AUTO mode, the default HEAT ON setting is 41°F (5°C). Heating stops
when the temperature is 27°F (15°C) above the start temperature.
You can define the start temperature below which the window will be
heated. The temperature can be defined between 32°F and 122°F (0°C to
50°C).