What is the working principle of the infrared sensor?

An infrared sensor is an electronic instrument that senses certain characteristics of the surrounding environment. It does this by emitting or detecting infrared radiation. The infrared sensor is also capable of measuring the amount of heat emitted by an object and detecting motion.

Infrared technology exists not only in industry but also in everyday life. For example, televisions use infrared detectors to interpret signals sent from the remote control. Passive infrared sensors are used in motion detection systems and LDR sensors are used in outdoor lighting systems. The main advantages of infrared sensors include low power requirements, simple circuitry and portable features.

Infrared sensors can be active or passive, and they can be divided into two main types:

Thermal Infrared Sensor - Use infrared energy as heat. Their photosensitivity is independent of the detected wavelength. The heat detector does not require cooling, but has a slow response time and low detection capability. Read more about thermal infrared sensors here.

Quantum Infrared Sensors - Provides higher detection performance and faster response times. Their photosensitivity depends on the wavelength. The quantum detector must be cooled to obtain an accurate measurement.