FIBER OPTIC LIQUID LEVEL INDICATOR

• US 3,713,338 A
• Filed: 01/18/1971
• Issued: 01/30/1973
• Est. Priority Date: 01/18/1971
• Status: Expired due to Term

• Current Assignee: Ronald W. Kind
• Original Assignee: Ronald W. Kind
• Inventors: Kind, Ronald W.
• Primary Examiner(s): Prince, Louis R.
• Assistant Examiner(s): Yasich, Daniel M.
• Application Number:
  US05/107,080
• Time in Patent Office: 743 Days
• Field of Search: 73/293,327,323,347,307 350/319 137/557 116/118R 73/299
• US Class Current: 73/293
• CPC Class Codes: G01F 23/164 using a diaphragm, bellow as transmitting element
• CPC Class Codes: G01F 23/2921 for discrete levels

Abstract

A fluid level indicator in which a fluid reservoir is divided into two fluid chambers by a flexible diaphragm. The first chamber is filled with a light absorbing fluid and the second chamber is connected to a container containing a fluid whose level is to be indicated so that the fluid is supplied to the second chamber at a pressure which corresponds to the level of the fluid in the container. An upright transparent vessel is mounted over an opening in the first chamber through which fluid may pass into the vessel. The pressure of the fluid in the second chamber due to the level of the fluid in the container exerts a force on the diaphragm to force the light absorbing fluid in the first chamber through the opening into the upright transparent vessel to a level at which the fluid pressures acting on each side of the diaphragm are equal. The ends of a series of fiber optic members are vertically aligned adjacent to the transparent vessel and the remaining ends are terminated at a remote viewing station. The fiber optic members are illuminated by a light source positioned opposite the ends of the fiber optic members and external to the transparent vessel. The fiber optic members in the region above the light absorbing fluid in the vessel are illuminated to provide an indication at the remote station of the level of the fluid in the container.

Claims

1. A liquid level indicator for indicating the level of a fluid in a container, the fluid having a specific gravity X comprising a reservoir having first and second chambers separated by a flexible pressure responsive member, the first chamber containing a light absorbing fluid having a specific gravity XY;

an upright transparent vessel mounted in a casing and having fluid communication with the first chamber;

means for transferring a portion of the fluid in the container to the second chamber at a pressure corresponding to the level and the specific gravity X of said fluid in the container to move the pressure responsive member to transfer the light absorbing fluid from the first chamber to the vessel at a level equal to 1/Y times the level of the fluid in the container;

a plurality of fiber optic light conducting members linearly disposed vertically in said casing, each of said fiber optic members having a first end terminating adjacent to said transparent vessel and a second end terminating at a remote viewing station, a plurality of fiber optic member having a light gathering end linearly disposed vertically in said casing with the other end thereof terminating adjacent to said transparent vessel and positioned oppositely of each of said first ends, and means for selectively illuminating region above the light absorbing fluid being illuminated thereby, the light absorbing fluid absorbing the light in the region below its level in the vessel to prevent illumination of the fiber optic members in said region below its level, whereby the level of the fluid in the container is indicated by the selective illumination of the fiber optic members at the remote viewing station.