Application of displacement sensor in testing machine field
Release date: May 20, 2019
In recent years, the output and varieties of domestic testing machines have been developed rapidly, covering all kinds of application fields required by modern engineering performance test. The technical level and quality of products have also been greatly improved, which has played a huge role in promoting the overall development of China's testing machine industry.
Le Jintao, a well-known expert in the field of domestic testing machine, thinks that there are five key cores in the technology of testing machine: first, the mechanical structure design and machining and assembly accuracy of the testing machine, which determines the crucial stiffness of the testing machine; second, the accuracy and resolution of the force sensor used to measure the force value; third, the accuracy and resolution of the extensometer or displacement sensor for measuring material deformation The fourth is the core controller of the testing machine; the fifth is the test software.
From the five core points considered by experts, it can be seen that the sensor is the core key point of the development of China's testing machine; in order to understand the role of displacement sensor in the testing machine, we will follow Beijing youliwei Technology Co., Ltd. to see the application of displacement sensor in the testing machine.
Displacement sensor is also known as LVDT (linear variable differential transformer), which can be divided into inductive displacement sensor, capacitive displacement sensor, photoelectric displacement sensor, ultrasonic displacement sensor and Hall displacement sensor.
Inductive displacement sensor is a kind of linear device which belongs to metal induction. When the power supply is turned on, an alternating magnetic field will be generated on the sensing surface of the switch. When the metal object is close to the sensing surface, the eddy current will be generated in the metal and the energy of the oscillator will be absorbed, so that the output amplitude of the oscillator will be linearly attenuated. Then, according to the change of attenuation, the object can be detected without contact. It has no sliding contact, is not affected by non-metallic factors such as dust, and has low power consumption and long service life. It can be used in various harsh conditions. Displacement sensor is mainly used in intelligent control of analog quantity in production line of testing machine.
Displacement is a quantity related to the movement of the object's position in the process of motion. The range of displacement measurement method is quite wide. Small displacement is usually detected by strain type, inductance type, differential transformer type, eddy current type and Hall sensor, while large displacement is measured by inductosyn, grating, capacitive grating and magnetic grating. Among them, grating sensor has been widely used in machine tool processing, testing machine and other industries because of its advantages such as easy realization of digitization, high precision (the highest resolution can reach nanometer level), strong anti-interference ability, no artificial reading error, convenient installation and reliable use.