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:
Feb. 05, 1991
Filed:
Jun. 23, 1989
Donald A Toon, Burlington, CA;
Douglas J Belshaw, Georgetown, CA;
Solinst Canada Ltd., Glen Williams, CA;
Abstract
A probe is disclosed, for lowering into a water-well or other hole. The probe includes conductivity measuring electrodes, to distinguish between e.g., water and contaminants, such as gasoline. The probe also includes an optical sensing facility to locate the junction between air and liquid. The probe comprises a transparent plastic tube, mounted inside a housing. A beam of light from a LED passes obliquely through the plastic tube and onto a photo-transistor. When liquid is encountered in the well, the liquid enters the tube: the change in refractive index now directs the beam away from the photo-transistor. The optical and conductivity sensors are both actuated at the same depth.