Flame Sensor uses a Light Dependent Resistor ( LDR ) for sensing flame. The flame sensor essentially senses the "Light" emitted by flame. It is usually suited only for oil burners in Boilers. It is not suitable for Furnaces, where background is refractory brich glows. These sensors sense all types of lights, including Sun light and rays emitted by electric bulb tube light.

Models :-
1) Flame Sensor ( FS - 1 ) with Front Viewing
2) Flame Sensor ( FS - 2 ) with Side Viewing
3) Flame Sensor ( FS - 3 ) Equivalent to Satronic Sensors