Sensor technology

作者： PbootCMS开发版PRO 时间：2023-02-17 16:41:32 阅读：1004

Definition:

A sensor is a device or device that can sense the specified measured signal and convert it into a usable output signal according to a certain rule. Our national standard (GB7665-2005) defines a sensor as "a device or device that can sense the measured signal and convert it into usable output signal according to certain rules".

As an important means of information acquisition, sensors, together with communication technology and computer technology, constitute the three pillars of information technology.

 

Effect:

Use physical, chemical and biological effects to convert the measured physical, chemical and biological quantities into electricity that meets the needs.

 

Introduction:

Sensor is the total number of devices or devices that can sense the specified measured signal and convert it into usable output signal according to certain rules

The measured quantity is usually non-electrical physical quantity, and the output signal is usually electric quantity. Today's world is facing a new technological revolution, which is mainly based on information technology, and sensor technology is considered as one of the three pillars of information technology. Some developed countries have listed sensor technology as the same position as communication technology and computer technology. With the development of modern science, As an emerging discipline closely related to modern science, sensor technology has also developed rapidly, and has been more and more widely used in industrial automation measurement and detection technology, aerospace technology, military engineering, medical diagnosis and other disciplines, while also promoting the development of various disciplines.

At present, there are more than 6000 companies producing sensors in the world, with tens of thousands of varieties. The United States regards the 1980s as the era of sensors, Japan lists sensors as major scientific and technological development projects from the 1980s to 2000, and China lists sensors as one of the key scientific and technological research and development projects of the "Tenth Five-Year Plan".  

 

Development history:

The sensing technology can be divided into three generations. The first generation is structured sensor. It uses the change of structural parameters to sense and transform signals. For example, the resistance strain sensor converts electrical signals by using the change of resistance when the metal material undergoes elastic deformation.

The second generation sensor is a solid sensor developed in the 1970s. This sensor is composed of solid components such as semiconductors, dielectrics and magnetic materials. It is made by using certain characteristics of materials, such as thermoelectric effect, Hall effect and photosensitive effect, which are respectively made into thermocouple sensor, Hall sensor, photosensitive sensor, etc.

In the late 1970s, with the development of integrated technology, molecular synthesis technology, microelectronics technology and computer technology, integrated sensors appeared. Integrated sensors include two types: the integration of the sensor itself and the integration of the sensor and subsequent circuits. For example, charge coupled device (CCD), integrated temperature sensor AD590, integrated hall sensor UGN3501, etc. These sensors mainly have low cost, high reliability, good performance The integrated sensor with flexible interface and other characteristics has developed rapidly, accounting for about 2/3 of the sensor market. It is developing towards low price, multi-function and serialization.

The third generation sensor is an intelligent sensor developed in the 1980s. The so-called intelligent sensor refers to its ability to detect, self-diagnose, process data and adapt to external information. It is the product of the combination of microcomputer technology and detection technology. In the 1980s, the intelligent measurement mainly took the microprocessor as the core, and integrated the microcomputer, memory and interface of the sensor signal conditioning circuit into a chip, which made the sensor have a certain degree of artificial intelligence. In the 1990s, the intelligent measurement technology has been further improved, realizing the intelligence at the sensor level, making it have the self-diagnosis function, memory function, multi-parameter measurement function and networking communication function.

 

Sensor application:

Sensor technology is an important link to realize test and automatic control. In the test system, it is used as a primary instrument positioning, and its main feature is that it can accurately transmit and detect information of one form, and convert it into information of another form.  [2]

Specifically, sensors refer to those components or devices that have the function of sensing (or responding) and detecting certain information of the measured object, and convert it into corresponding output signals according to certain rules. If there is no sensor to accurately and reliably capture and convert the measured original information, all accurate testing and control will not be achieved. Even the most modern electronic computer, without accurate information (or converted reliable data) and undistorted input, will not be able to fully play its due role.

There are many kinds of sensors and their principles. The resistance strain sensor is a force measuring device widely used in electronic scales and various new mechanisms. Its accuracy and range are selected according to the needs, and the high accuracy requirements are not significant for a certain use; Too wide range will also reduce the measurement accuracy, and will cause high cost and increase technological difficulties; Therefore, it is very important to properly select the accuracy and range according to the requirements of the measurement object. However, no matter what conditions and occasions the sensor is used, it is required to have stable performance, reliable data and durability. Therefore, while studying high-precision sensors, we must pay attention to the research of reliability and stability. Sensor technology, including the research, design, trial production, production, detection and application of bed concealed weapons, has gradually formed a relatively independent specialized discipline.

In general, because the location of the sensor is not ideal, under the comprehensive influence of temperature, humidity, pressure and other effects, it can cause sensor zero drift and sensitivity change, which has become a serious problem in use. Although people have taken temperature compensation and sealing and moisture-proof measures in the process of making sensors, it is closely related to the strain gauge, the high performance of the adhesive itself, the accuracy and proficiency of the adhesive technology, the selection of elastomer materials and the formulation of cold and hot processing technology, which can not be ignored, and all need to be carefully designed and manufactured. At the same time, it is also necessary to pay attention to the installation method of the sensor, the setting of the support structure, and how to overcome the transverse force.

 

Development trend and application prospect:

By comparing the development history and research status of sensor technology, it can be seen that with the rapid development of science and technology and the maturing of relevant conditions, sensor technology has gradually received more and more people's high attention to the research and development of sensor technology today, especially the development of new sensor technology based on photoelectric communication and biological principles, which has become an important symbol and power to promote the progress of the national and even the world's information industry.

Because the sensor has dynamic characteristics such as frequency response and step response, as well as static characteristics such as drift, repeatability, accuracy, sensitivity, resolution, linearity, etc., the change and turbulence of external factors will inevitably cause small stability of the sensor's own characteristics, which will have a great impact on its practical application. This requires us to focus on the working principle and structure of the sensor, Specify corresponding basic requirements for sensors on small occasions to optimize their performance parameters and indicators to the greatest extent, such as high sensitivity, anti-interference stability, linearity, easy adjustment, high precision, no hysteresis, long working life, repeatability, anti-aging, high response rate, environmental impact resistance, interchangeability, low cost  wide measurement range  small size  light weight and high strength.

At the same time, according to the analysis of the research status of sensor technology at home and abroad and the idealized requirements for the performance parameters of sensors, the development trend of modern sensor technology can be analyzed and summarized from four aspects: first, the development of new materials, new processes and new sensors; One is to realize multi-function, high-precision, integration and intelligence of sensors; The third is to realize the miniaturization of the sensing technology hardware system and components; The fourth is to realize wireless networking through the cross-integration of sensors and other disciplines.