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:
Mar. 04, 2003
Filed:
Apr. 24, 2001
Andrew J. Cocking, Santa Cruz, CA (US);
Wai Yin Cedric Chan, Santa Cruz, CA (US);
James W. Livingston, Santa Cruz, CA (US);
Johnson Diversey, Inc., Sturtevant, WI (US);
Abstract
A conductivity measurement system provides one or more DC pulses to first and second electrodes submerged in an aqueous solution such as, for instance, the wash water of an industrial dishwasher. The voltage at the first electrode is measured at a sequence of at least three predetermined times after initiation of one of the DC pulse. A non-linear curve fitting function is applied to the sequence of at least three voltage measurements to calculate the voltage at the first electrode at the beginning of the DC pulse(s), commonly denoted as being at time t=0. The resulting calculated voltage at time t=0 is then used to calculate the conductivity of the solution, and/or to control operation of the a chemical dispenser, and/or to perform another predetermined system analysis or system control function. In addition, the difference between two of the measured voltages, such as the first and second measured voltages, is compared to a predetermined threshold value to determine whether the electrodes are so contaminated that polarization compensation is no longer feasible, thereby signaling that the electrodes should be cleaned or replaced.