Method for designing electromagnetic shielding body of liquid capacitance-type sensor

Abstract

The invention relates to a design process of a shield for resisting electro-magnetic interference in a liquid capacitance type sensor, which comprises firstly determining the frequency spectrum of an interference source needing to be shielded, secondly determining the sensitivity characteristic of the sensor, conducting the sensitivity test for a device which is actually interfered to obtain the sensitivity characteristic curve line, thirdly calculating the round hole size of the shield according to the relative theories of cut-off waveguide, the actual shielding requirements and the working environment request of the sensor, fourthly building a simulation model in a computer, and conducting value emulation calculation, comparing the shielding results, and finally instructing to process real objects according to the calculated results. The invention solves the problem of the electro-magnetic interference of the sensor, and facilitates the sensor to work normally under the electro-magnetic radiation, and the shield which is designed has light weight and excellent oil permeability, and can not affect the normal working.

Description

technical field [0001] The invention relates to a design method for a shielding body of a liquid capacitive sensor, which belongs to the field of basic application. Background technique [0002] A liquid capacitive sensor is a sensor that measures parameters such as the volume of a liquid. The capacitance value of the capacitive sensor is very small and must be converted into a corresponding voltage, current or frequency signal by the measurement circuit. There are many types of conversion circuits, and bridge circuits, resonant circuits, frequency modulation circuits, and operational amplifier circuits are more commonly used at present. [0003] However, with the rapid development of science and technology, the electromagnetic environment in which electronic equipment works is becoming more and more complex. Due to its structural characteristics, liquid capacitive sensors are more sensitive to external electromagnetic radiation, that is, when there is external electromagn...

AI Technical Summary

Problems solved by technology

[0003] However, with the rapid development of science and technology, the electromagnetic environment in which electronic equipment works is becoming more and more complex.

Due to its structural characteristics, liquid capacitive sensors are more sensitive to external electromagnetic radiation, that is, when there is external electromagnetic interference, the normal work is affected, and the measured parameters are no longer accurate, which brings great difficulties to the measurement work.

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