SAW weighing sensor

Abstract

The invention relates to a SAW weighing sensor. The weighing sensor comprises a surface acoustic wave device and a weighing mechanical structure, wherein the surface acoustic wave device is placed on the weighing mechanical structure; the surface acoustic wave device comprises a substrate, a piezoelectric film deposited on the substrate, an interdigital electrode and a reflecting grating, and the interdigital electrode and the reflecting grating are deposited on the piezoelectric film; the weighing mechanical structure comprises a platform, a base fixed on the platform, a lever connected with the base in a hinge manner, a tray forming a sliding block structure with the lever, and a probe of which one end is connected with the tail end of the lever and the other end is in contact with the central position of the surface acoustic wave device; and the contact area of the probe and the central position of the surface acoustic wave device is a contact area. According to the invention, the pressure change is sensed through the frequency drift of the SAW, the sensed pressure can be amplified or reduced, the sensing range is improved, the mass of an object to be measured can be accurately measured, and the effect of adjustable range is realized.

Description

technical field [0001] The invention relates to the field of sensors, in particular to a SAW weighing sensor. Background technique [0002] With the continuous development of the field of production process automation and the increasing demand for load cells in real life, the market has higher technical requirements for load cells: reduce volume and quality, improve response sensitivity, small measurement errors, increase varieties, realize digitalization and controllable. The load cell is actually a device that converts the quality signal into a visual electrical signal output. If the sensor wants to accurately measure the quality of the object under test in its environment, it is very important to select the load cell correctly. On the one hand, it is Will the working principle of the sensor be affected by the environment in which it is located, resulting in measurement deviations; on the other hand, whether the sensor matches the working environment, involves its safety ...

AI Technical Summary

Problems solved by technology

[0003]At present, the existing weighing sensors mainly include resistance strain type, capacitive type, etc. Among them, the resistance strain type sensor is the most widely used, but its disadvantage is that it is suitable for large strain There is a large nonlinearity and the output signal is weak

Taking the product based on the capacitive principle as an example, the measured change is converted into a change in capacitance, but its output impedance is high, the load capacity is poor, and it is easily affected by external interference to cause instability. Secondly, it is greatly affected by parasitic capacitance. Not only reduces the sensitivity of the sensor, but also these capacitances often change randomly, which will make the instrument work very unstable and affect the measurement accuracy

[0004]Although the existing products and technologies can realize the weighing function of the measured object, there are certain limitations in various conversion principles, and there are still technical or economic problems in the products. Therefore, for this, there is an urgent need for a new and simple and effective method that can realize real-time monitoring and obtain the quality of the measured object conveniently and accurately

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