ANALOG CONDUCTIVE LIQUID LEVEL SENSOR

摘要

An analog conductive liquid level sensor for conductive liquids having three probes. The invention provides an analog output in proportion to the level or volume of the fluid. Triangular shaped probes are closer together at the top than at the bottom with the respective triangular apexes at the bottom resulting in a nearly linear output voltage in accordance with the fluid level. The shape of the probes can be changed to proportion the voltage output to the fluid volume of an irregular shaped container. A driver probe near the bottom of the container provides a constant area exposed to the conductive liquid. This probe provides compensation for the variations in fluid conductivity which could introduce errors in the level indication in the container as found with two probe systems.

主权项

1. A liquid level sensor for measuring a conductive fluid in a container, said sensor comprising:
a driver probe which is always in contact with the fluid in the container; a ground probe of predetermined shape; a sensing probe also of predetermined shape; wherein said probes are able to provide the liquid level in the container if the container is regular-shaped or are able to provide the volume of liquid in the container if the container is irregular-shaped.