MH-440D infrared sensor is a general-purpose intelligent infrared gas sensor (hereinafter referred to as the sensor). Dependence, stable performance, long life; built-in temperature compensation. The sensor is a compact and high-performance sensor that combines the mature infrared absorption gas detection technology with micro-machining and sophisticated circuit design. It is easy to use, can be directly used to replace catalytic combustion elements, and is widely used in various occasions where flammable and explosive gases exist.