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:
Sep. 13, 1977
Filed:
Apr. 10, 1975
Applicant:
Inventor:
Paul R Goldberg, Palo Alto, CA (US);
Assignee:
Smith Kline Instruments, Inc., Sunnyvale, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; G01J / ; G01J / ;
U.S. Cl.
CPC ...
356205 ; 250565 ; 356 88 ; 356 93 ; 356 94 ; 356 96 ; 356223 ; 356229 ;
Abstract
Apparatus for measuring the optical density of a sample includes a dual beam spectrophotometer producing sample and reference signals which are compared with the discharge curve of a resistive-capacitive circuit to provide start-stop signals, the time interval between the two signals being indicative of optical density. Embodied within this linearization means is a novel method of correcting for nonlinearities due to stray light. The start and stop signals are used to drive a linear ramp generator, the stop signal terminating the ramp at an analog signal level indicative of optical density.