Non-contact type capacitance induction level sensor

Abstract

A non-contact capacitance induction liquid level sensor comprises an insulation shell, a capacitance induction metal part and a liquid level detection circuit. The insulation shell is vertically arranged, the capacitance induction metal part is vertically arranged inside the shell, and the liquid level detection circuit is arranged inside the shell; the liquid level detection circuit comprises an analog input port which is used for being connected with the capacitance induction metal part, and a liquid level measurement module which is used for detecting a capacitance value of the analog input port, and obtaining a current liquid level value according to a corresponding relation between a preset capacitance value and the liquid level; and the capacitance induction metal part is connected with the analog input port. The invention provides the non-contact capacitance induction liquid level sensor which can be effectively used for a long time even under a harsh environment.

Description

(1) Technical field [0001] The invention belongs to a liquid level sensor. (2) Background technology [0002] The traditional capacitive water level sensor has electrodes exposed in the water, and water acts as a medium to change the capacitance between the electrodes, thereby detecting changes in the water level; the traditional water resistance water level sensor has multiple electrodes, but when the water passes through the electrodes, the gap between the electrodes A weak current flows to detect changes in the water level; if the above two sensors are used in water with high temperature and poor water quality, it is easier to scale and cover the electrodes, resulting in detection failure. For example, the water level sensor in a solar water heater often has a short service life due to the above reasons, and in the thunderstorm season in summer, it is often vulnerable to lightning damage to the entire circuit, which hinders the promotion of solar water heaters as an energ...

AI Technical Summary

Problems solved by technology

[0002] The traditional capacitive water level sensor has electrodes exposed in the water, and water acts as a medium to change the capacitance between the electrodes, thereby detecting changes in the water level; the traditional water resistance water level sensor has multiple electrodes, but when the water passes through the electrodes, the gap between the electrodes A weak current flows to detect changes in the water level; if the above two sensors are used in water with high temperature and poor water quality, it is easier to scale and cover the electrodes, resulting in detection failure

For example, the water level sensor in a solar water heater often has a short service life due to the above reasons, and in the thunderstorm season in summer, it is often vulnerable to lightning damage to the entire circuit, which hinders the promotion of solar water heaters as an energy-saving product and the industrial development of solar water heater water temperature and water level instruments.

[0003] The magnetic float and reed switch type water level sensor will also be stuck due to scale on the float, resulting in failure of water level detection

[0004] The traditional gasoline oil level sensor converts the position change of the oil level into the resistance change of the resistance array through the float ball, crank lever, and row rod, and gives the oil level signal. Because it is in a state of motion for a long time, mechanical reciprocating motion is also prone to failure

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