According to the international development trend and the present situation in China, modern instruments can be roughly divided into six categories according to their application fields and their own technical characteristics, namely, industrial automation instruments and control systems, scientific instruments, electronic and electrical measurement, instruments and meters, medical instruments, various special instruments, sensors and instrument components and materials. Industrial automation instruments and control systems mainly refer to various detection instruments, actuators and automatic control system devices used in industry, especially in process industry. Scientific instruments mainly refer to instruments and meters used in scientific research, teaching experiments, measurement and testing, environmental monitoring, quality and safety inspection, etc. Electronic and electrical measuring instruments mainly refer to special and general instruments for testing and measuring in various frequency bands such as low frequency, high frequency, ultra-high frequency and microwave. Medical instruments mainly refer to instruments used for life science research and clinical diagnosis and treatment. All kinds of special instruments refer to instruments used in agriculture, meteorology, hydrology, geology, ocean, nuclear industry, aviation, aerospace and other fields. Scientific instruments can be subdivided into 14 subcategories, namely electronic optical instruments, ion optical instruments, X-ray instruments, spectroscopic instruments, chromatographic instruments, spectroscopic instruments, electrochemical instruments, biochemical separation and analysis instruments, gas analysis instruments, microscopes and imaging systems, chemical reaction and thermal analysis instruments, acoustic vibration instruments, mechanical performance testing instruments (material testing machines) and photoelectric measuring instruments. Among them, all kinds of optical instruments and analytical instruments have the fastest development, the widest application and the largest market capacity. Although modern instruments are roughly classified, there are actually many intersections. For example, many special instruments are scientific instruments.
2, the development trend of modern instruments and meters
The development of international instruments and meters is extremely rapid. Taking analytical instruments in scientific instruments as an example, the total annual sales of analytical instruments in the world increased from $25.6 billion in 2000 to $365.438+0.6 billion in 2002, with an annual growth rate of over 65.438+0. 1%, which is 3-4 times of the global economic growth rate. The main development trends of international instruments and meters in recent 10 years are:
The appearance of digital technology has improved the precision, resolution and measurement speed of analog instruments by several orders of magnitude, laying a good foundation for realizing test automation. With the introduction of computer, the function of the instrument has changed qualitatively, from measuring a single parameter to measuring the characteristic parameters of the whole system, from simple acceptance and display to control, analysis, processing, calculation and display output, from measuring with a single instrument to measuring with a measuring system. With the further penetration of computer technology in instruments, in addition to the traditional time domain and frequency domain tests, data domain tests also appear in electronic instruments. In the 1990s, the breakthrough of instrumentation science and measurement technology was the improvement of instrumentation intelligence. The appearance of a large number of DSP chips has greatly strengthened the digital signal processing function of instruments and meters; With the development of microcomputer, instruments and meters have stronger data processing ability and image processing function; Fieldbus technology is a rapidly developed network communication technology for various field automation devices and their control systems in the 1990s. Internet and Internet technology will also enter the control field. Modern instrument products will develop in the direction of computerization, networking, intelligence and multifunction. Interdisciplinary comprehensive design and precise manufacturing technology enable it to obtain all-round information of the analyzed, detected and controlled objects more quickly, sensitively, reliably and simply. In the coming 10 year, a higher degree of intelligence should include a series of functions such as understanding, reasoning, judgment and analysis, which is the result of the combination of numerical value, logic and knowledge, and the symbol of intelligence is the expression and application of knowledge. Using the new effects of physics, high-tech and its achievements, new sensor technologies and test instruments with high sensitivity, high stability and strong anti-interference ability are developed. For example, the high temperature superconducting quantum interferometer (SGUID) is used to develop measuring and testing instruments, physical testing instruments, geographical and geological instruments, chemical analysis instruments, medical instruments and nondestructive material testing instruments. Optical fiber and optical glass are detected by ellipsometer. Combined with near-field optics, not only the fine surface structure can be measured, but also the material of the measured object can be distinguished according to the polarization information reflected by near-field optics, which is a new exploration of experimental research at present. The tunable frequency-stabilized laser spectrometer technology is applied to the high-precision measurement of geometric quantities, mechanical quantities and various intangible quantities, and a new generation of micro-fiber guided laser interferometer is developed Its measuring range can be from nanometer to several meters or even larger, and the resolution can reach10 mm. It can also be used for weighing, developing new electronic balance, high-precision electronic belt scale, high-resolution manometer and so on. Developing nano-measurement technology and establishing nano-measurement test standards are very active topics in the research of measurement and test technology. Analytical instruments are undergoing a revolutionary change. The traditional analytical techniques such as optics, heat, electrochemistry, chromatography and spectroscopy have changed from the classical chemical precision mechanical electronic structure and manual operation application mode in the laboratory to the integrated and automatic structure of optics, machinery, electricity and calculation (computer), and are developing towards a more veritable intelligent system (with highly intelligent functions such as self-diagnosis, self-control, self-adjustment and self-judgment). Due to the rapid development of high technology represented by information technology, the working principle, design idea and design method of scientific instruments have changed obviously. The key technologies are as follows: (1) Micro-analysis technology, that is, miniaturization and miniaturization of analytical instruments, including micro-control, micro-machining, micro-detection, micro-light source, differential optical system, micro-sensor, etc. (2) Biological and chemical sensors include the application of new sensing technology in analytical instruments, and the application of biochip technology, new chemical sensing technology and intelligent sensor technology in the development of analytical instruments. (3) Imaging technologies include generalized imaging, nano-scale ultra-high resolution imaging and information processing. The specific fields are: nuclear magnetic resonance technology, automatic image analysis and synthesis technology, imaging spectroscopy technology and near-field optical imaging technology. (4) Instrument combination technology realizes the combination of various sciences and technologies through information separation and special software interface technology, and realizes the comprehensive analysis of complex systems such as trace component analysis, structure analysis and morphology analysis, such as chromatography-mass spectrometry and chromatography-spectrum analysis. LIMS (Laboratory Information Management System) has been widely used. Instruments can be connected to the Internet, manufacturers can diagnose remotely, guide correct use or give maintenance guidance, and users of similar instruments or users engaged in the same analysis can directly enjoy data and information. Remote calibration and value traceability of instruments are just around the corner. The application of analytical instruments in biology, environmental protection, medicine and other fields related to human survival and development is changing with each passing day. The development of modern high-tech military also promotes the application of analytical techniques and instruments, and the sensitive and accurate field poison detection and life support tasks greatly expand the application field of analytical instruments.
According to the development trend of international instruments and meters mentioned above, it can be clearly seen that the development of modern instruments and meters has the following main characteristics:
(1) Technical indicators have been continuously improved.
Just as the slogan of the Olympic movement is higher, faster and stronger, instruments and meters are the eternal pursuit of improving the technical indicators of measurement and control. In terms of technical range indicators of instrumentation and measurement control, such as voltage from nanovolts to 1 million volts; Resistance from superconductivity to1014Ω; Harmonic measurement to 5 1 time; The acceleration varies from 10-4 to 104g; The measured frequency is1010 Hz; The measured pressure is108 pa; ; The temperature measurement range is from near absolute zero to 10 10℃ and so on. In terms of improving the measurement accuracy index, the industrial parameter measurement is above 0.02%, and the aerospace parameter measurement is above 0.05%. The measurement accuracy and the accuracy achieved by scientific instruments keep pace with the times. In order to improve the sensitivity of measurement, it is developing to the level of single particle, molecule and atom. Improve the measurement speed (response speed), static 0. 1~0.2ms, dynamic1μ s. To improve the reliability, it generally requires 20,000 ~ 50,000 hours, and high reliability requires 250,000 hours. Stability (annual variation) < 0.05% (for high-precision instruments) or < 0. 1% (for general instruments). In addition, the environmental adaptability of products has been continuously improved.
(2) the first application of new scientific research achievements and the adoption of a large number of high and new technologies.
As the first-hand tool for human beings to understand and transform the material world, modern instruments and meters are the most basic tools for human beings to carry out scientific research and engineering technology development. Humans have long understood the truth that "if a worker wants to do a good job, he must sharpen his tools first." New scientific research achievements and discoveries such as information theory, cybernetics, system engineering theory, micro and macro world research achievements and a large number of high and new technologies, such as weak signal extraction technology, computer software and hardware technology, network technology, laser technology, superconducting technology, nanotechnology, etc., have become an important driving force for the development of instrumentation and measurement and control science and technology. Modern instruments and meters have not only become a new high-tech product.
③ A single device is miniaturized and intelligent, and can be used independently, embedded and networked.
A large number of new information technology products such as sensors, large-scale and ultra-large-scale integrated circuits, computers and expert systems are used in measurement and control instruments, and they are constantly developing towards miniaturization and intelligence. Judging from the appearance of "chip instrument" and "chip laboratory", the miniaturization and intelligence of a single device will be the long-term development trend. From the perspective of application technology, the embedded connection and networking application technology of micro-miniaturization and intelligent equipment has been paid attention to.
④ The scope of measurement and control is expanding to three-dimensional and global working mode, and the measurement and control is developing to systematization and networking.
With the development of the established area of measurement and control instruments to three-dimensional, global and even planetary, instruments and measurement and control devices are no longer in the form of a single device, but will inevitably develop in the direction of systematization and networking of measurement and control devices. For example, in the measurement and control system of a large hydropower station, there are thousands of sensors that only detect dam safety, and there will be more than 10,000 detection and control points (I/O measurement and control points) for the state and water level of each generator set. In order to realize the normal power generation and transmission of large hydropower stations, the measurement and control devices of each measurement and control point must be networked to form an organic measurement and control network system. Another example is the satellite measurement and control system. There are thousands of sensors on the satellite. First, it is necessary to form a complete automatic measurement and control subsystem with various measurement and control equipment on the satellite, and then form a wide-area measurement and control system with the measurement and control systems of multiple ground stations.
⑤ Portable, handheld and personalized instruments and meters have made great progress.
With the development of production and the improvement of people's living standards, people pay more and more attention to their quality of life and health. It is an important trend to detect the quality of various commodities and foods closely related to people's lives and prevent diseases. On-site, real-time online scientific instruments, especially the health status and disease early warning instruments used by families and individuals, will be greatly developed.
3. Key technologies for the development of modern instruments and meters
Starting from the development trend and characteristics of modern instrument science and technology, we can list the key technologies of instrument development as follows.
① sensing technology
Sensing technology is not only the basis of instrumentation detection, but also the basis of instrumentation control. This is not only because the control must be based on the input information, but also because the accuracy and state of the control must be perceptible, otherwise the control with unclear control effect is still blind control.
Broadly speaking, sensing technology must perceive three aspects of information, namely, the state and information of the objective world, the state and information of the tested and controlled systems, and the state information and control instructions that operators need to know. It should be noted here that the objective world is endless, and the perception of the objective world by the measurement and control system mainly focuses on the objective environment related to the target (referred to as the established target environment for short), and environmental information outside the established target environment can be collected by other methods. The controlled system can be a simple object or a single sample, a complex automation system without direct manipulation, a large-scale automation system or social activity system operated by people (groups), or a human body. Sensing technology for human health, physiological and psychological state is the foundation and core of medical diagnosis and treatment instruments. Operators can be single, but in the case of systematization and networking, they are often groups of operators in different positions.
In a narrow sense, sensing technology is mainly to detect useful information in the objective world, including sensitive technology for useful measurement, involving the working principle of various disciplines, remote sensing and telemetry, new materials and other technologies; Information fusion technology involves sensor distribution, weak signal extraction (enhancement), sensor information fusion, imaging and other technologies; Sensor manufacturing technology involves micromachining, biochip, new technology and so on.
② System integration technology
System integration technology directly affects the application breadth and level of instrumentation and measurement and control science and technology, especially has a decisive impact on the automation degree and benefit of large projects, large systems and large devices. It is a system-level information fusion control technology, including system requirements analysis and modeling technology, physical layer configuration technology, information communication conversion technology of various parts of the system, and application layer control strategy realization technology. When the operators are operating groups in different positions, it also includes the demand analysis technology of operators at all levels.
③ Intelligent control technology
Intelligent control technology is a technology that human beings monitor intelligent tools, equipment and systems in a near-optimal way through measurement and control system to achieve the set goals. It is a technology directly related to the benefit of measurement and control system and the key to the development of information technology to knowledge economy technology. Intelligent control technology can be said to be the most important and critical software resource in the measurement and control system. Judging from the current development trend, in the computer measurement and control system with three-level structure of enterprise information ERP/MES/PCS, the price of software has exceeded three times that of hardware. However, the price of advanced control software of automatic measurement and control system in petrochemical, metallurgical, electric power and pharmaceutical industries exceeds the price of system hardware. Intelligent control technology includes humanoid feature extraction technology, automatic target recognition technology, knowledge self-learning technology, environment adaptive technology, optimal decision-making technology and so on.
④ Man-machine interface technology
Man-machine interface technology is mainly for the convenience of instrument operators or operators of major equipment and major systems to equip instruments to operate instruments or major equipment and major systems. It makes instruments and meters a direct operating tool for human beings to understand and transform the world. The operability and maintainability of the instrument, even the main equipment and systems equipped with the instrument, are mainly completed by man-machine interface technology. Instruments and meters have beautiful, exquisite, simple operation and convenient maintenance, which often becomes an important condition for people to choose instruments and meters and the main equipment and systems equipped with instruments and meters.
Man-machine friendly interface technology includes display technology, hard copy technology, man-machine dialogue technology, fault manual intervention technology and so on. Considering that the operator has developed from a single machine to many different positions under the condition of systematization and networking, the man-machine friendly interface technology is developing to the man-machine large-scale system technology. In addition, with the development of systematization and networking of instruments and meters, more and more attention has been paid to the technology of identifying specific operators and preventing non-operators from interfering.
⑤ Reliability technology
With the increasing application of instruments and measurement and control systems, reliability technology plays an important role in improving combat effectiveness and maintaining normal work, especially in some military, aerospace, electric power, nuclear industry facilities, large-scale projects and industrial production. Once these departments fail, it will lead to disastrous consequences. Therefore, the reliability, safety and maintainability of equipment, especially the reliability, safety and maintainability of the whole system including the controlled system, are particularly important. For example, on August 15, 2003, the accident of power failure in the United States was definitely not caused by the expansion of some equipment failures!
The reliability technology of instrumentation and measurement and control system includes not only the reliability technology of measurement and control device and measurement and control system itself, but also the fault handling technology when the device and system under test fail. The reliability of measurement and control devices and systems includes fault self-diagnosis, self-isolation, fault self-repair, fault tolerance, reliability design and reliability manufacturing.