The role of sensors in automated test and control systems

Sensor technology is a very important part of testing and automatic control. This technique correctly delivers and detects some form of information and transforms it into other forms of information. For example, the load sensor can linearly convert the value of an object's force into an electrical signal output for instrumentation and other control machines for industrial automation.

In particular, sensors are those components or devices that have the function of sensing (or responding to) and detecting certain information of the object under test and converting it to a corresponding outputtable signal according to certain rules. If the original information measured by the sensor is not correctly and reliably captured and transformed, all correct testing and control cannot be achieved. Even modern computers do not have the correct information (or transform reliable data), and the input without distortion is not sufficient. Play a role.

There are many types of sensors and the principles are different. Resistance strain sensors are widely used in electronic scales and various new force measuring devices. Its accuracy and range is too high and does not make much sense for some applications. Too wide a range will also reduce measurement accuracy, resulting in excessive cost and increased technical difficulty. Therefore, the accuracy and range must be correctly selected according to the requirements of the measurement object. However, the sensor used in any condition and occasion requires stable performance, reliable data and durability. Therefore, it is necessary to study the reliability and stability while studying high-precision sensors. At present, sensor technology, including research, design, trial production, production testing and application of bed weapons, has gradually formed a relatively independent professional discipline.

In general, due to the unsatisfactory position of the sensor, the zero drift and sensitivity change of the sensor under the combined influence of temperature, humidity and pressure have become a serious problem in use. Although everyone used the countermeasures of temperature compensation and sealing waterproofing in the whole process of making the controller, it is happy with the strain gauge and the adhesive itself, the precision and skill of the pasting technique, the selection of the elastomer material and the cold. The formulation of thermal processing technology is closely related, and no one can be ignored. It needs to be carefully planned and manufactured. In addition, attention must be paid to the mounting method of the sensor, the setting of the support structure, and the method of overcoming the lateral force. The sensor as a primary meter usually consists of a sensor and a conversion element. The conversion element is a sophisticated bridge. Therefore, the resistance strain sensor repeatedly used by the load cell is mainly composed of an elastomer, a strain gauge, an adhesive, and various compensation resistors. His stability also depends on the combined effects of these factors. This article discusses this issue, presents a shallow opinion, and discusses it with peers.

The first is the elastic element. Elastomers are usually made of high quality alloy steel and non-ferrous metals such as aluminum and beryllium bronze. It affects the stability of the elastomer, mainly due to its metallographic structure and residual stress after various treatments. Fully consider the equilibrium relationship between the release of the ground stress and the binding force of the polyurethane elastomer structure. If the internal stress is released, the aging treatment should be carried out. If the natural aging method is selected, the release will be slow. Long period, often not available, must be reduced by human factors, usually to remove the stress inside the surface of polyurethane elastomer: vacuum pump quenching and fatigue pulsation and resonance. In this way, the residual stress can be greatly reduced, and the normal long-term natural aging can be completed in a short time, and the tissue performance can be more stable.

Followed by strain gauges and adhesives. The stability of the strain gauge is the foil itself. There are many kinds of resistive alloys for making strain gauges. Among them, the use of Kangkang alloy is widely used. It has good stability, high fatigue life and small temperature coefficient of resistance. It is ideal. Wire grid manufacturing materials. In addition, the instability caused by adverse effects should be eliminated during the manufacture of the strain gauge. For example, the bond strength between the wire grid and the primer, the bond strength between the strain gauge and the elastomer, and the release of internal stress in the primer are all unstable factors. In addition, the adhesion of strain gauges is also one of the most important elements. The quality of this work directly affects the bonding quality of the glue, and even the measurement accuracy. If the film is not strict, the technology is not skilled, even if it is used even better. The strain gauges did not help.

The excellent characteristics of the controller will greatly increase the sustainability of the industrial production automation control system, increase productivity, and have a key effect on the company's development. At present, with the maturity of domestic sensor technology, the application of sensors is more and more extensive, and it plays a very good supporting role in industrial applications.