After the development of electric unit combination instruments characterized by simulation technology and DDZ-S series instruments characterized by digital analog hybrid technology, in 1983, Honeywell Corporation of the United States first introduced a new generation of intelligent pressure transmitters to the manufacturing industry, marking the transition from analog instruments to digital intelligent instruments. At that time, this type of intelligent transmitter had the characteristics of high precision, remote calibration, and flexible configuration, and informed users that although the initial purchase cost was high, it would be compensated for by lower operating and maintenance costs. In the following decade, intelligent pressure transmitters from other foreign companies have also been adopted on some production lines, including Rosemount, Foxboro, YOKOGAWA, Siemens, E&H, Bailey, Fuji, and ABB. However, due to the lack of high-speed intelligent communication standards, low user demand for high-precision monitoring, and relatively weak service mechanisms such as training, intelligent applications at that time were not optimistic and only accounted for about 20% of the market.
With the rapid development of microelectronics, computers, networks, and communication technologies, as well as the continuous improvement of comprehensive automation, intelligent instruments are currently widely used in the field of industrial automation, and their technology has also undergone rapid development in the past twenty years. At present, foreign intelligent instruments account for the vast majority of the international application market. How to combine the current industrial application experience of intelligent instruments and quickly track the application of international intelligent cutting-edge technologies to the development and research of intelligent instruments in China has become a prominent issue in revitalizing national intelligent instruments and meters.
The advantages and characteristics of intelligent instruments
The widespread application of intelligent instruments in the field of industrial automation benefits from their outstanding technological advantages and characteristics, such as high stability, high reliability, high accuracy, and easy maintenance. Taking intelligent transmitters as an example, intelligent instruments have the following advantages:
(1) High precision intelligent transmitters have high accuracy. By utilizing the built-in microprocessor, the impact of static pressure and temperature changes on the detection components can be measured in real-time. Through data processing, nonlinearity can be corrected, and hysteresis and reproducibility can be compensated, making the output signal more accurate. In general, the accuracy is ± 0.1% of the maximum range, and the digital signal can reach ± 0.075%
(2) Strong functionality
Intelligent transmitters have a variety of complex computing functions, relying on internal microprocessors and memory to perform square root, temperature and pressure compensation, and various complex calculations.
(3) Wide measurement range
The maximum range ratio of a regular transmitter is 10:1, while a smart transmitter can reach 40:1 or 100:1, and the migration can reach 1900% and -200%, reducing the specifications of the transmitter, enhancing universality and interchangeability, and bringing many conveniences to users.
(4) Strong communication function
Intelligent transmitters can be operated by hand operators, which can be inserted into the corresponding socket of the transmitter on site or connected to the signal line of the transmitter in the control room for zero and range adjustment and change. Some transmitters have two output modes, analog and digital, such as the HART protocol, which lays the foundation for achieving fieldbus communication.
(5) Comprehensive self diagnosis function
The fault result information of the transmitter self diagnosis can be detected through a communicator.
Suggestions for the Future Development Direction of Intelligent Instrument Technology and Its Applications
(1) The intelligence level of intelligent instruments needs to be further improved
The degree of intelligence of intelligent instruments characterizes their breadth and depth of application. Currently, intelligent instruments are only in a relatively low level of primary intelligence stage, but some special processes and application scenarios have put forward high requirements for the intelligence of instruments. However, current intelligence theories such as neural networks, genetic algorithms, wavelet theory, chaos theory, etc. already have potential application foundations, This means that we need and have the ability to vigorously develop advanced intelligent instrument technology based on specific application needs.
(2) Stability and reliability of intelligent instruments
The stability and reliability of instrument operation are the primary concerns of users, and intelligent instruments are no exception. With the continuous expansion of intelligent instrument technology and the launch of new intelligent instruments on the market, we need to always grasp a principle: the application of each intelligent new technology needs to be tested by practice, whether users have the confidence and courage to be the first to eat crabs. This requires parallel development of security and reliability technologies.
(3) The potential functional applications of intelligent instruments need to be maximized
At present, the practical application of intelligent instruments in the field of industrial automation has not yet maximized their functions, and more than half of their overall functions have been applied. The main reason for this application situation is that the overall architecture of control systems ignores technological advantages such as fieldbus, which requires instrument manufacturers to establish good partnerships with users, strengthen long-term cooperation, and promote long-term benefits through short-term investment, By establishing a control system architecture of "intelligent instruments+fieldbus" and establishing an optimized investment concept, we aim to achieve a harmonious and win-win situation.
(4) Continue to increase investment in the development of intelligent instruments in China
The technology and application of intelligent instruments still need to go through a relatively long period of mature development, and the development of domestic intelligent instrument technology and products is already facing greater challenges. This situation calls on the domestic instrument industry to jointly explore the development issues of intelligent instruments, respond to the fierce international competition market, and shoulder the historical mission of the instrument industry. Under the increasingly favorable national and government support policies, we adhere to the principles of production, learning, and The close integration of research and development will continue to increase investment in the development of intelligent instruments in China.