Resistance type water level sensor

Abstract

Resistance type water level sensor is produced from cascade resistances and leading out probes, or resistance bar (strip, tube) with continuous distributed resistance, or enwinding resistance wire on outside insulating plastic rod. The sensor is realized based on principle of resistance built in the sensor and liquid to be measured with partial conduction property. There is good linear relation between total resistance of sensor and depth of sensor immersed to water or liquid. Measuring resistance value of sensor obtains depth value of sensor immersed to water or liquid.

Description

1. Technical field [0001] The sensor is a device that can sense changes in water levels or liquid interfaces, has low cost and reliability, and can be widely used in automatic monitoring of various water levels and liquid interface changes. 2. Background technology [0002] Automatic monitoring of water level or liquid interface changes is a very important work, which is of great significance in flood water level measurement, groundwater level monitoring, liquid change perception in containers, and water level display in living facilities. In addition to the simplest ruler measurement method, the current water level monitoring in the field mainly uses buoy mechanical sliding, RF capacitance (RFcapacitance) or RF impedance (RF impedance) measurement, hydrostatic pressure conversion (pressure sensor), radar or microwave ranging, Acoustic or ultrasonic ranging method to achieve. Although the measurement accuracy of several other methods is relatively high except for the mechan...

AI Technical Summary

Problems solved by technology

Although the measurement accuracy of several other methods is relatively high except for the mechanical sliding method of the buoy, the higher cost and the larger space required for equipment installation have brought difficulties to the wide application of these devices and the construction of monitoring networks. It is even more difficult to apply these methods to monitor the change process of water bodies or other liquid interfaces in the horizontal direction on a small scale.

Although the radio frequency impedance measurement method uses the theory of measuring the impedance or resistance of the liquid to obtain the position of the liquid interface, it also needs a metal conductor containing the liquid as the other pole of its capacitor to be measured during the implementation process, so in It is difficult to realize the measurement of natural water level in the field

Some people also proposed the idea of ​​using the conductive properties of the liquid to judge whether the liquid has reached a certain position or determine the position of the interface, but the water level or liquid interface change sensor based on this idea has not yet been applied and reported.

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