Ultrasensitive Liquid Level Sensor
AssigneeSonics & Materials, Inc.
InventorsJohn Anthony Triunfo, Michael Svend Stefansen
Life of this patent
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Abstract
An electronic liquid level sensor configured to verify a height of a liquid in a reservoir between minimum and maximum levels includes at least one reference electrode, a minimum level electrode and a maximum level electrode. Each of the minimum level electrode and the maximum level electrode is configured as a pin having at least one tapered portion with a diameter between 0.010″ and 0.035″ at a widest point of the tapered portion, an angle of taper of the at least one tapered portion with respect to a longitudinal axis of the pin being between 181° and 193°, a total length of the at least one tapered portion being between 0.110″ and 0.150″, and a radius of curvature of a tip of the pin being less than 0.015″.
Claims24
An electronic liquid level sensor configured to verify a height of a liquid in a reservoir between minimum and maximum levels, said sensor comprising:
- a housing having a bottom wall;
- at least one reference electrode extending downward from the bottom wall of said housing to a reference level height;
- a minimum level electrode extending downward from the bottom wall of said housing to a minimum level height;
- a maximum level electrode extending downward from the bottom wall of said housing to a maximum level height;
- wherein the minimum level height is vertically lower than the maximum level height, and wherein the reference level height is vertically lower than both the minimum level height and the maximum level height;
- a first indicator responsive to a circuit being closed between said minimum level electrode and said at least one reference electrode such that when the liquid level reaches the minimum level height the first indicator is activated;
- a second indicator responsive to a circuit being closed between said maximum level electrode and said at least one reference electrode such that when the liquid level reaches the maximum level height the second indicator is activated;
- and
- wherein each of said minimum level electrode and said maximum level electrode is configured as a pin having at least one tapered portion with a diameter between 0.010″ and 0.035″ at a widest point of the tapered portion, wherein an angle of taper of the at least one tapered portion with respect to a longitudinal axis of the pin is between 181° and 193°, wherein a total length of the at least one tapered portion is between 0.110″ and 0.150″, and wherein a radius of curvature of a tip of the pin is less than 0.015″.
An electronic sensor configured to verify a height of deionized water in a reservoir between minimum and maximum levels, said sensor comprising:
- a housing having a bottom wall;
- a common reference electrode extending downward from the bottom wall of said housing to a reference level height;
- a minimum level electrode extending downward from the bottom wall of said housing to a minimum level height;
- a maximum level electrode extending downward from the bottom wall of said housing to a maximum level height;
- wherein the minimum level height is vertically lower than the maximum level height, and wherein the reference level height is vertically lower than both the minimum level height and the maximum level height;
- wherein each of said minimum level electrode and said maximum level electrode is comprises a threaded portion configured so as to allow for the minimum level height and the maximum level height to be adjustable;
- at least one foot extending from the bottom wall of said housing to at least the same extent as does the common reference electrode;
- a first light responsive to a circuit being closed between said minimum level electrode and said at least one reference electrode such that when the water level reaches the minimum level height the first light is illuminated;
- a second light responsive to a circuit being closed between said maximum level electrode and said at least one reference electrode such that when the water level reaches the maximum level height the second light is illuminated;
- wherein each of said minimum level electrode and said maximum level electrode is configured as a steel pin with a polished nickel plating and having at least one tapered portion with a diameter between 0.010″ and 0.035″ at a widest point of the tapered portion, wherein an angle of taper of the at least one tapered portion with respect to a longitudinal axis of the pin is between 181° and 193°, wherein a total length of the at least one tapered portion is between 0.110″ and 0.150″, and wherein a radius of curvature of a tip of the pin is less than 0.015″;
- and
- wherein each of said minimum level electrode and said maximum level electrode is configured so as to cause the water to exhibit a surface tension effect of 0.008″ or less, whereby a known liquid level tolerance range of one thousandth of an inch or less is achieved.
Dependencies are inferred from the claim text.