Flame module Interface module and number 13 comes with LED build a simple circuit to produce flame warning lamp 13 comes with digital interfaces of the LED, the flame sensor connected digital three interfaces, when the flame sensor senses There are key signal detected, LED lights, otherwise off.Sensor for flame wavelengths between 760 nm to 1100 nm infrared is most sensitive 60 degree detection sensor Two outputs mode: AO: analog output- real-time output voltage signal on the thermal resistance DO: when the temperature reaches a certain threshold- the output high and low signal threshold adjustable via potentiometer