The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 1991
Filed:
Oct. 23, 1990
Applicant:
Inventor:
Brian C Goodrich, Los Gatos, CA (US);
Assignee:
Watkins Johnson Company, Palo Alto, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
G01F / ;
U.S. Cl.
CPC ...
73293 ; 250577 ; 340619 ;
Abstract
A liquid level sensor assembly for a liquid-chemical bubbler includes a removable cylindrical LED housing, which is removably retained within a cylindrical axial bore of a sealing nut. The LED housing is removable from within the cylindrical axial bore without breaking the seal between the chemical liquid within the bubbler and the ambient atmosphere. The LED housing holds an LED transmitter and a photodiode detector, which respectively sends light into a cylindrical quartz rod and receives reflected light from the quartz rod, where the reflected light is used to measure the level of the chemical liquid within the bubbler.