The reflective type and through-beam type of infrared counter tube are two different infrared sensors, and they have some differences in structure, working principle and application scenarios.
1. Structural differences.
The structure of the reflective infrared counter tube is relatively simple, mainly composed of a transmitter tube and a receiver tube. The transmitter emits infrared rays of a certain wavelength, which are reflected back to the receiver tube through the reflective surface. When an object or person passes over a reflective surface, it blocks out a portion of the infrared rays, causing a change in the received signal.
The through-beam infrared tube consists of a pair of independent transmitters and receivers. The transmitter emits infrared rays of a wavelength that are not reflected but travel through space to the receiver. When an object or person passes through an infrared beam, a portion of the infrared light is blocked, causing a change in the received signal.
Second, the difference in working principle.
The reflective infrared counter tube works by using the law of reflection of light. When the infrared light emitted by the transmitter meets the reflective surface, it is reflected back to the receiving tube. If a person or object blocks the reflective surface, the infrared signal received by the receiving tube is weakened or disappears, triggering the signal output.
The through-beam infrared counter-tube uses the principle of linear propagation of light. When the infrared rays emitted by the transmitter pass through space to the receiver, if someone or object blocks the infrared beam, then the receiver will receive the signal change in the obscured part, thus triggering the signal output.
3. Differences in application scenarios.
The reflective infrared tube is suitable for some occasions that need to detect objects or human movements, such as security monitoring, automatic doors, etc. Due to its simple structure and low cost, it is more common in some low-cost applications.
The through-beam infrared tube is suitable for some occasions that need to detect changes in the distance of objects or human bodies, such as automatic faucets, automatic flushing toilets, etc. Due to the structural characteristics of its through-beam type, it can detect objects or human movement at a greater distance, so it is more common in some high-end applications.