Plastic thickness measuring device based on plane capacitive sensor and method thereof

Abstract

The invention belongs to the field of capacitance sensing technology and relates to a plastic thickness measuring device based on a plane capacitive sensor. The plastic thickness measuring device is used for measurement of the thickness of a plastic membrane and comprises a sensor, a direct current (D) / alternating current (A) and A / D conversion circuit, a single chip microcomputer and an upper computer. The sensor is the plane capacitive sensor and is composed of three metal electrodes. One metal electrode is an excitation electrode, and the other two metal electrodes are receiving electrodes. Excitation signals generated by the singe chip microcomputer are loaded on the excitation electrode after going through DA conversion and power amplification. Signals received from the two receiving electrodes are respectively sent into the single chip microcomputer after going through signal modulation and AD conversion. The single chip microcomputer sends obtained capacitance value (C12 and C13) between the excitation electrode and the two receiving electrodes into the upper computer. The upper computer compares the capacitance value (C12 and C13) and a relation curve of pre-stored capacitance ratio value and the thickness of the plastic membrane. Consequently, thickness measurement of the plastic membrane is realized. The invention simultaneously provides a plastic thickness measuring method realized through the device. The plastic thickness measuring device has the advantages of being simple, quick, and low in cost.

Description

technical field [0001] The invention belongs to the technical field of capacitance sensing, and relates to a device and a detection method for detecting the thickness of a plastic film. Background technique [0002] Polyvinyl chloride, polyethylene, polypropylene and other plastic films are widely used in industry, agriculture and food packaging, etc., with a large output and many varieties and specifications. Thickness is one of the most important quality indicators of the finished plastic film, which must be controlled during the production process. [0003] There are four methods of measuring and controlling the thickness of plastic film at home and abroad: one is to use a thickness gauge to detect, and the electronic computer performs automatic control. Although this method has high accuracy, the electronic and mechanical equipment of this method is complicated and expensive. The second is based on manual online monitoring, manual adjustment and control, which is cost-e...

AI Technical Summary

Problems solved by technology

[0003] There are four methods of measuring and controlling the thickness of plastic film at home and abroad: one is to use a thickness gauge to detect, and the electronic computer performs automatic control. Although this method has high accuracy, the electronic and mechanical equipment of this method is complicated and expensive. Not much; the second is based on manual online monitoring, manual adjustment control, low cost, and remarkable effect, which is adopted by general forces, but the test results vary from person to person, and are very fragmented, which cannot fully reflect the production quality

The three are β-ray thickness gauges developed in the 1950s. The technology has matured and the accuracy is relatively good, but there are disadvantages such as the harm of radioactive rays to the human body of workers, high technical requirements for use and maintenance, high price, and slow response speed. , the last one is the infrared thickness gauge developed in the 1970s. Although it overcomes some shortcomings of the β-ray thickness gauge, its adaptability is poor

Images