초록 ▼

A liquid level detector “stick”includes a column of Hall-cells adapted to be mounted vertically in a liquid\s containing tank. One or more toroidal magnets are slidably fitted about the stick. A float elevates the topmost magnet to the level of liquids in the tank. If the liquids comprise two immisc

A liquid level detector “stick”includes a column of Hall-cells adapted to be mounted vertically in a liquid\s containing tank. One or more toroidal magnets are slidably fitted about the stick. A float elevates the topmost magnet to the level of liquids in the tank. If the liquids comprise two immiscible parts, a second of the magnets may be floated at the surface of the denser liquid part. A very low power electronic system continuously scans the Hall-cells and determines which particular one or ones of them are adjacent a magnet. This detector may be used in a gasoline station storage tank that may also contain water, providing accurate measure of both liquids. It is also capable of operating in a monitor mode for sounding an alarm when a change in the level of either liquid part occurs that may indicate leakage into or from the tank or an attempted theft.

대표청구항 ▼

A liquid level detector comprising: a column of Hall-cells adapted to be mounted vertically in a tank containing a liquid; a magnet being adapted to move vertically at a substantially fixed spacing from said column of Hall-cells; a float means for maintaining said magnet at the surface of said liqui

A liquid level detector comprising: a column of Hall-cells adapted to be mounted vertically in a tank containing a liquid; a magnet being adapted to move vertically at a substantially fixed spacing from said column of Hall-cells; a float means for maintaining said magnet at the surface of said liquid to increase the magnetic field at the Hall-cell adjacent to said magnet, and an electronic means for sequentially applying DC power to each of said Hall-cells in said column, and for sensing, shaping and summing the outputs of all said Hall-cells, whereby the time period, between said applying DC power to a particular predetermined one of said Hall-cells and the occurrence in said summed outputs of a Hall-cell output signal that is characteristic of a Hall-cell in the field of said adjacent magnet, provides a unique indication of said liquid level.