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:
Aug. 15, 1989
Filed:
Sep. 08, 1987
Drew E Sunstein, Hollis, NH (US);
Clifford D Caseley, Hudson, NH (US);
Circuits and Systems, Inc., Amherst, NH (US);
Abstract
The present invention provides a system for transmission loss comparison. On embodiment of the present invention compares the transmission losses through optical paths through a first solution and a second solution. This embodiment includes first and second light sources for transmitting light through the first and second solutions. Also provided are first and second light detectors corresponding to the first and second light sources, and comparison means for comparing the outputs of the two detectors in order to determine which solution is darker. In addition, this embodiment includes a common gain balance configuration means for calibrating the relative gain of the two light detectors in order to compensate for signal differences between each source/detector path arising from various mechanical or optical factors. Further included is a dark solution compensation bias to compensate for differences between each source/detector path arising from spectral differences between the two light sources. In order to stabilize the measurement decision, the system also provides source modulation hysteresis, wherein a feedback path is provided between the output of the comparison means and one of the light sources.