Introduction of Automatic Sensors and Instruments

With the rapid development of modern science and technology, the scope of application of automation has become more and more extensive, and the level of automation has become an important benchmark to measure the modernization level of an industry at this stage. However, in order to truly improve the level of automation, it is necessary to ensure the smooth operation of sensor automation. With the gradual development of the electrical engineering industry, the level of instrument automation has also been significantly improved.

Future trend of automation sensor

Development direction of automatic sensors

With the development of science and technology, information technology has developed rapidly. Information has promoted the development of industrial automation instruments and control systems, resulting in great changes in the structure overview and design concept of instruments, which have become instruments with the basic functions of ordinary instruments and special functions that ordinary instruments do not have. The development of industrial automation instruments is based on the main control system devices and intelligent instruments of the general line, as well as special and special automation instruments, so as to expand the service area, enable the instrument system to develop in the direction of digitalization, intelligence, and networking, and realize the perfect transformation of automation instruments from analog technology to digital technology.

Intelligence

According to the development situation of industrial instruments, intelligence is the central part. In the past, industrial automation instruments can only be completed through regulators or DCS. At present, an intelligent transmitter can complete all functions, realize independent regulation and improve the reliability of the overall system.

Precision

With the improvement of the requirements of industrial production on the quality of finished products, the country also has certain requirements on energy conservation and emission reduction, so the accuracy of measuring instruments and control systems should be improved.

Installation and commissioning of instrument automation equipment

Installation of instrument automation equipment

An automatic instrument is composed of many automatic parts, and it is a relatively complete automation technology tool. Generally speaking, it can have many functions at the same time, such as measurement, control, alarm, and recording. The automation instrument itself is an independent system, but it is also a subsystem of the entire automation system. The automatic instrument can be simply interpreted as an information machine. Its main function is to convert different forms of information. At the same time, it can also convert input signals into output signals. The signal can be expressed according to time or frequency and can be modulated into a continuous analog quantity or intermittent digital quantity form during signal transmission.

Work before installation

During installation, first, collect data, carefully analyze the operation instructions of thermal automation instruments, then carefully read the installation contents and install according to the contents. In combination with the inspection standards of automation instruments, study a series of problems that may occur in the installation process, sort them into reports, and then purposefully select and analyze technologies to ensure orderly installation. Secondly, conduct overall research on installation technology, establish a professional installation team to ensure construction safety, and re-test the thermal automation instruments before installation. Once it is found that they are inconsistent with the actual situation, replace them with new instruments in a timely manner. Finally, the authority and responsibility shall be clarified and the above contents shall be analyzed and discussed with experts to ensure that the selected technology can make the instrument no longer have problems due to installation errors.

Technology during installation

After completing the work before installation, we should focus on the technical work during installation, so we need to analyze the types of instruments. First of all, for the instruments responsible for pressure evaluation, explosion-proof technology should be selected during installation, mainly relying on the installation of explosion proof connectors in the instrument lines to ensure the closure of the interface and prevent the explosion. Secondly, temperature evaluation is carried out for instruments. Temperature evaluation is the most important instrument in the thermal power production link. Therefore, we should select resistors with low cost and strong function. Platinum is the most standard raw material at present. Platinum is added to the instrument. During installation, electronic technology is used to directly penetrate lines with small diameters into the instrument to ensure its stability of the instrument. Finally, for the instrument to detect the liquid position, the instrument with buoyancy shall be selected to resist the buoyancy. Therefore, the mechanical operation seal technology can be used to prevent the pointer protective sleeve of the instrument from leakage and corrosion within the specified range. Grounding technology shall be adopted when installing automatic thermal supervision instruments.

(1) Installation of instrument equipment. Before the installation of instruments and equipment, first, understand the overall performance of automation instruments and their working indicators, and understand the installation specifications of such instruments; Secondly, the performance of all equipment and materials shall be inspected in the early stage of instrument installation to ensure their normal application; Finally, some special signal instruments are used to intelligent the measuring instruments and equipment, so that they can be installed only after meeting the design requirements.

(2) Installation of thermal pipeline and wiring. In the installation of instrument equipment, there are many aspects involved, including signal collection, parameter measurement, power distribution, pipe tapping, etc., so there is a huge workload in the installation of instrument pipes and line pipes. In this link, it is necessary to ensure the scientific and reasonable installation position, keep away from magnetic field and interference sources, reduce the impact of environmental problems on instrument application, and reduce the number of reworks.

Commissioning of instrument automation

After the instrument is installed, it needs to be debugged. The commissioning stage mainly includes process testing and secondary joint calibration, and the defective parts are optimized to ensure the smooth operation of all functions and the correctness of instructions and wiring.

Measurement of automatic instrument parameters

First, before analyzing the failure of the field instrument, it is necessary to have a simple understanding of the production process, production process, and actual conditions of the relevant instrument. Second, before analyzing and checking the failure of the field instrument system, it is necessary to learn about the daily production load and the change of raw material parameters from the relevant staff and check the records of the failed instrument. Third, if there is no fluctuation in the instrument recording curve, the system may have a fault. Because most recorders in current automatic instruments are computer systems with high sensitivity, any change in parameters can directly cause fluctuations. In this case, the relevant staff can manually change the process parameters and observe whether the instrument recording curve fluctuates. If there is no fluctuation, it can be basically concluded that the instrument system is the main cause of the problem; If there are normal changes, it can be basically judged that the instrument system is not the direct cause of this fault. Fourth, when changing process parameters, it is found that the recording curve has a significant change, or directly jumps to the maximum or minimum, then it can be basically concluded that the fault occurs in the instrument system.

Effective measures for maintenance and fault avoidance

(1) When the closed-loop automatic regulating system fails, the instrument shall be switched to manual operation first, and then the position of its regulating valve shall be changed according to the allowable range of the current process. During this process, it is necessary to check whether the valve position indicated by the indicator is the same as the site valve position, and at the same time, observe the feedback change in detail.

(2) Automatic instruments shall be inspected regularly and maintained and repaired regularly according to relevant regulations. The inspection of components and transmitters is the focus of patrol inspection and periodic calibration. The main inspection scope includes the accuracy of the signal, whether the wiring is reliable, and whether the components are abnormal. During the maintenance and repair of the transmitter, special attention should be paid to the withstand voltage, linear variation, and other technical indicators, which are important conditions to ensure the normal operation of the transmitter. The parallelism of the nozzle baffle of the pneumatic transmitter shall be maintained to ensure that its mechanical mechanism is free from any looseness or jamming. The electric transmitter should first ensure the correct orientation of the aluminum sheet and the plane coil and adjust its oscillating current to keep it in the most sensitive section.

It is necessary to conduct regular inspections of the automation instrument and equipment and carry out routine maintenance according to the methods specified in the relevant regulations. In case of any failure, it shall be solved in a timely manner.

(3) To ensure the cleanliness of the instrument, lubricate and wipe the mechanical sliding parts regularly, especially in some dusty and severely corroded environments, check and clean them regularly, so as to better ensure the normal operation of the instrument.

Conclusion

In a word, the maintenance of automatic instruments is an important work that cannot be ignored, and the detection and control of automatic instrument failures are also complicated. Therefore, in order to correctly judge and deal with the instrument failure the first time, the relevant staff must have solid theoretical knowledge and rich practical experience, and can quickly provide solutions to the failures in different situations, thus ensuring the good operation of the enterprise.