A sensor is a device or apparatus that converts physical or chemical phenomena into electrical signals or data and outputs them, serving as the "perception" in electronics applications.
Just as humans act based on the information they perceive through sight and hearing, electronic devices also collect information from sensors, which are perceptual devices, and display or operate based on that information.

Sensors are used not only in industrial fields such as factory automation, but also in transportation systems such as aircraft and automobiles, home appliances, and digital devices such as personal computers, smartphones, and digital cameras.
Especially for IoT, sensors are indispensable. In developing IoT devices, it is becoming very important to select the most suitable sensor from among many sensors. Knowing sensors is the first step in building IoT.

Sensors include not only sensors that measure physical phenomena such as light, sound, temperature/humidity, pressure, distance, electricity, magnetism, velocity, acceleration, and angular velocity, but also sensors that measure gases in the atmosphere, There are chemical sensors that examine the composition of, for example.
In addition, when classifying sensors according to the materials they are composed of, there are semiconductor sensors that use changes in the properties of semiconductor elements due to changes in physical quantities, and biosensors that use biological substances (enzyme sensors, microbial sensors, and immunosensors).

Sensors have come a long way today. Compact, high-performance, and compounded sensors have been developed, and the range of applications has expanded accordingly.

For example, small digital composite sensors that can measure atmospheric pressure, temperature, etc. have appeared and are already being incorporated into smartphones, wearable devices, drones, etc.
Accelerometers that can measure acceleration in the three directions of XYZ are also used in game controllers.
Contactless sensors are attracting attention in industrial IoT. This is because various data can be measured without contact and there is no need to worry about wear or damage to the detection target. Non-contact sensors use various methods such as infrared, magnetic, and optical sensors. In particular, optical high-temperature sensors, which measure temperature by detecting radiant heat, are being adopted in many factories because they can measure the temperature of many products simultaneously and instantly. is.

Millimeter-wave sensors that utilize electromagnetic waves with frequencies of 30 GHz to 300 GHz are also attracting attention in the industrial world. Since millimeter waves have a very high frequency band, they are highly linear and can be treated like lasers, even though they are radio waves. Therefore, it is expected to be applied to automotive and industrial equipment in particular.
In addition, face recognition sensors that analyze and match images captured by cameras with software are also used in building entry/exit management, immigration control at airports, and entrance checks at concerts.
Fingerprint authentication, which analyzes fingerprint information read by a touch sensor and compares it with pre-registered fingerprint information, is also widespread.
In the form of thermography, taste sensors, and gas leak detectors that use sensors that read infrared rays, the application areas of sensors are expanding in our homes as well.
The future of electronics applications will continue to expand through the skillful use of sensors.