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:
May. 03, 1977
Filed:
Jun. 17, 1976
Harold W Doddington, Gainesville, FL (US);
Donald M Sheppard, Gainesville, FL (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
An instrument for determining salt concentration in water by measuring elrical conductivity. A probe of electrical insulating material has one electrode mounted on the exterior surface of the probe and a second electrode is mounted in a cavity in the probe. A horizontal slit is provided at one end of the probe and a small vertical hole connects the horizontal slit with the cavity to provide a fluid passageway. A sinusoidal current excitation source is provided to energize the probe and the electrical current density between the two electrodes is small except in the vertical hole where the current density becomes very large. The resistance between the electrodes at any instant is governed by the resistance of the fluid in the vertical hole. The resistance of the fluid is measured by processing the voltage which exists between the two electrodes of the probe through a differential amplifier, rectifier, filter and output amplifier arrangement to provide a voltage output which is inversely proportional to the salinity of the fluid being tested.