Widely used in human body induction switch, alarm, infrared thermometer
and infrared imaging and other aspects. Can provide users with different
induction Angle, induction distance, size, test ratio. Fresnel lens
action: one is focusing action; Second, the detection area is divided
into a number of bright areas and dark areas, so that the moving objects
entering the detection area can generate changes in the form of
temperature changes on the PIR(passive infrared detector).