【正文】 their output signal types and the production of their materials and processes. Working principle of the sensor can be divided into physical sensors and chemical sensors two categories: Sensor working principle of the classification of physical sensors that physical effects, such as the piezoelectric effect, magostriction, ionization, polarization, thermal, optical, magic and electric effects. Small changes in the amount of the measured signal will be converted into electrical signals. Chemical sensors, including those with chemical adsorption, electrochemical reaction, a causal relationship between the phenomenon of the sensor, the measured signal will be small changes in volume converted to electrical signals. Some sensors can not divided into physics, can not be divided into chemical classes. Most of the physicsbased sensor is functioning. Many problems of chemical sensor technology, such as reliability issues, the possibility of mass production, prices, etc., solve such problems, the application of chemical sensors will have tremendous growth. Dynamic characteristic The socalled dynamic characteristics, is the change in the input sensor, its output characteristics. In practice, the sensor39。s own sense ans, the study of natural phenomena and laws, and production activities in their functions on far enough. To meet this situation, we need sensors. It can be said sensor is an extension of human senses, also known as electronic features. The arrival of the new technological revolution, the world entered the information age. In the course of the use of information, we must first resolve is to obtain accurate and reliable information, and sensors is to obtain information in the field of natural and production of the main ways and means. In modern industrial production, especially automated production process, the use of various sensors to monitor and control the various parameters of the production process, so that devices work best in the normal state or condition, and to achieve the best quality products. Therefore we can say, without a large number of good sensors, modern production base will be lost. In the basic science research, a more prominent position sensor. The development of modern science and technology into many new areas: for example, thousands of light years to observe the macro level of the vast universe, to observe microscopically small particles cm the world, vertical, to observe the evolution over hundreds of years of celestial bodies , a short response to the s moment. In addition, there was even a matter of deepening understanding, developing new energy, new materials, play an important role in a variety of extreme technology such as ultrahigh temperature, ultralow temperature, high pressure, ultrahigh vacuum, powerful magic field, ultraweak magic bagging, etc. . Obviously, to obtain a large number of human senses can not directly access the information, Not patible with sensors is impossible. Many basic scientific research obstacles, first of all to obtain information on the object is difficult, and a new highly sensitive detection mechanism and the emergence of sensors, often lead to breakthroughs in the field. The development of a number of sensors is often a pioneer in the development of marginal subjects. Sensor has already perated into, such as industrial production, space development, marine exploration, environmental protection, resource survey, medical diagnostics, biotechnology, and even conservation areas and so most of the pan. It is no exaggeration to say that, from the vast space, the vastness of the ocean, as well as a variety of plex engineering systems, almost every modern project, are inseparable from a variety of sensors. Thus, the sensor technology in economic development, promote the important role of social progress is very clear. Countries in the world attach great importance to the development of this area. I believe in the near future, there will be a leap in sensor technology, to achieve status mensurate with its important new level. Sensor classification Different views can be classified on the sensors: they transform principle (Transducer on the basic physical or chemical effect)。