An China infrared beams sensor is usually composed of three parts, which are: a transmitter, a receiver and a detection circuit. The transmitter, with a calibrated lens, focuses the light toward the receiver, and the receiver cable connects the set to a vacuum tube amplifier. The receiver of the infrared beams sensor is composed of a photodiode, a phototransistor and a photocell. 

Photodiodes are the most common sensors components today. The appearance of the photodiode of the China infrared beams sensor is the same as that of a general diode, except that there is a window embedded with glass on its shell to facilitate the entry of light. The photodiode of the China infrared beams sensor works in a reverse biased working state and is connected in series with the load resistor. When there is no light, it is the same as ordinary diodes, and the reverse current is very small, which is called the "dark current" of the photodiode. When there is light, the "current-carrying" of the photodiode of the China infrared beams sensor is excited to generate electron holes, which is called is "photoelectric current carrying".
In addition, there are emission plates and optical fibers in the structural elements of the China infrared beams sensor. The corner reflector is a solid emitting device, which is composed of small triangular pyramid reflective materials, which can make the beam return from the reflector accurately. The emission plate can change the emission angle in the range from zero to twenty-five with the optical axis, so that the light beam is almost from one emission line, and after reflection, it still returns from this reflection line, so that the China infrared beams sensor can play better efficiency.