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. 12, 1991
Filed:
Apr. 14, 1989
Michael Zoechbauer, Oberursel, DE;
Walter Fabinski, Kriftel, DE;
Hartmann & Braun AG, Frankfurt, DE;
Abstract
Interferometric equipment for detecting a substance having a structure preferably a periodic or quasiperiodic absorption spectrum; the equipment includes a source of radiation, a path for that radiation that includes a sample cell with the substance to be detected, an interference filter and a detector, and is improved in that the interference filter is constructed as an electrically tunable filter, including a plate or cell element with semitransparent reflective boundaries serving as electrodes; an electrical voltage is applied to said electrodes such that the transmission characteristics of the filter is varied and the amplitude of the voltage as applied to these electrodes is an indication of that variation; and the thickness of the plate or cell is selected to meet one of the following criteria (i) a distance between the interference lines produced equals a distance of absorption lines within a periodic absorption spectrum of said substance; (ii) the equipment causes a line to be separated from the radiation having a bandwidth which is small as compared with a spacing between two absorption lines of the substance to be found (iii) the equipment causes a line to be separated from the radiation, to overlap an edge of an absorption band of the substance to be directed.