Sensors have a wide range of applications in our life, ranging from a car to a smart bracelet. The sensors contained in them are the crystallization of human wisdom. But this article does not talk about these products, we just talk about sensors.

If you ask, who changed the world? Apple? Samsung? Is it Jobs? None of them. I said sensors changed the world.

What, sensors? Isn't the sensor something that existed long ago? Why is it saying that it has changed the world now?

Yes, sensors are not new. As early as N years ago, logic elements, memory elements and sensing elements have been juxtaposed as three major components of electronic systems. From pressure measurement to mechanical measurement, to the development of electrical measurement has undergone many changes. In the sensor era, it is a historical transformation of electronic components. With the popularity of cloud concept, it has gradually been neglected, but at the same time, sensor components are playing their own world in the black horse's posture.

So what is a sensor?

Sensor is a kind of detection device, which can sense the measured information and transform it into electrical signal or other required information output according to certain rules to meet the requirements of information transmission, processing, storage, display, recording and control.

How do they define sensors?

The national standard GB7665-87 defines sensors as "devices or devices that can sense specified measured components and convert them into usable signals according to certain rules (mathematical function rules). They are usually composed of sensitive elements and conversion elements".

China Internet of Things School-Enterprise Alliance believes that the existence and development of sensors, so that objects have the sense of touch, taste and smell, so that objects slowly become alive.

Sensors are defined in the New Wechsler Dictionary as "devices that receive power from one system and usually send it to the second system in another form".

The Role of Sensors

In order to obtain information from the outside world, people must resort to sensory organs. It is not enough to study natural phenomena and laws and their functions in production activities solely by people's own sensory organs. In order to adapt to this situation, sensors are needed. Therefore, it can be said that the sensor is the extension of the human five senses, also known as the electric five senses.

With the advent of the new technological revolution, the world began to enter the information age. In the process of utilizing information, the first problem to be solved is to obtain accurate and reliable information, and sensors are the main ways and means to obtain information in the field of nature and production.

In modern industrial production, especially in automated production process, various sensors should be used to monitor and control the various parameters in the production process, so that the equipment can work in a normal or priority state, and the product can achieve better quality. Therefore, it can be said that without many excellent sensors, modern production will lose its foundation.

Sensors have already penetrated into a wide range of fields, such as industrial production, cosmic development, ocean exploration, environmental protection, resource survey, medical diagnosis, bioengineering, and even cultural relics protection. It is no exaggeration to say that almost every modern project, from the vast space to the vast ocean to all kinds of complex engineering systems, is inseparable from all kinds of sensors.

Therefore, the important role of sensor technology in economic development and social progress is very obvious. All countries in the world attach great importance to the development of this field. It is believed that in the near future, sensor technology will make a leap to a new level commensurate with its important position.

Composition of sensors

Sensors are generally composed of four parts: sensing element, conversion element, conversion circuit and auxiliary power supply, as shown in Figure 1.

Sensor directly senses the measured value and outputs the physical quantity signal which has a definite relationship with the measured value; converter converts the physical quantity signal output by the sensitive element into electrical signal; converter circuit is responsible for amplifying and modulating the electrical signal output by the converter element; converter and converter circuit generally need auxiliary power supply.

Main Functions of Sensors

The functions of sensors are often compared with the five sensory organs of human beings.

Photosensitive Sensor-Vision

Acoustic Sensor-Audio

Gas Sensor-Olfaction

Chemical Sensor-Taste

Pressure Sensitive, Temperature Sensitive and Fluid Sensor-Touch Sensor

Classification of sensitive elements:

Physics is based on the physical effects of force, heat, light, electricity, magnetism and sound.

Chemistry, based on the principle of chemical reaction.

Biology, based on molecular recognition functions such as enzymes, antibodies, and hormones.

Usually, according to its basic sensing function, it can be divided into ten categories: thermal sensor, photosensitive element, gas sensor, force sensor, magnetic sensor, humidity sensor, sound sensor, radiation sensor, color sensor and taste sensor.

Technical Characteristics of Sensors

China's sensor industry is at a critical stage of development from traditional sensors to new sensors. It reflects the general trend of the development of new sensors to miniaturization, multi-function, digitalization, intelligence, systematization and networking. Sensor technology has undergone many years of development, and its development can be divided into three generations.

The previous generation is a structural sensor, which uses the change of structural parameters to sense and transform signals.

The second generation is a solid-state sensor developed in the 1970s, which consists of semiconductors, dielectrics and magnetic materials.