LM393 flame sensor is mostly sensitive to flame, and it will also respond to ordinary light, generally used in fire alarms and other purposes. It can be directly connected to the microcontroller IO port. The sensor should be kept a certain distance from the flame, so as not to damage the sensor because of high temperature. The test distance for the lighter flame should be 80cm, the larger the flame, the larger the test distance. Small plates analog output mode and the AD conversion process can help get higher accuracy.

Specifications:

Can detect the flame or the light with the wavelength at the range of 760 nm to 1100 nm.
The detection angle is about 60 degrees, extremely sensitive to the flame spectrum.
Sensitivity is adjustable. (shown in blue digital potentiometer)
The comparator output with clean signal,good waveform,strong driving ability of more than 15mA
With an adjustable precision potentiometer to adjust the sensitivity
Operating voltage: 3.3V-5V
The output form: DO digital switching outputs (0 and 1) and AO analog voltage output
A fixed bolt hole is set for easy installation
Small plates PCB size: 3.2cm x 1.4cm
Using LM393 comparator with wide voltage