RD-623 is a type of thermal infrared sensor produced by Zhengzhou Winsen Electronic Technology Co., Ltd., which has high sensitivity and excellent signal-to-noise ratio. It adopts a dual compensation structure to effectively resist interference from the external environment. The elements and amplifiers are all encapsulated in TO-5, which saves users the time of designing circuits and mounting. Excellent anti-interference performance, since the entire circuit is encapsulated in a metal package, the electromagnetic shielding effect is better, the interference filter has a high cutoff depth and strong anti-white light ability. It is mainly used in security, intrusion alarm, indoor access control, automatic lighting switch, safety door, home, smart home, intelligent office appliances, etc.