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. 15, 1979
Filed:
Feb. 28, 1977
Gunther Schunck, Bruchkobel, DE;
Albert Randow, Bruchkobel, DE;
Leybold-Heraeus GmbH & Co. KG., Cologne, DE;
Abstract
Process for the photo-optical measurement of the absorption behavior of solid, liquid and gaseous media. A measurement light beam from an optical radiation source is made intermittent by a rotating chopper comprising a rotatable metal wheel. The chopper frequency is maintained constant by regulation of the speed of the metal wheel by two alternating-current magnets inducing eddy currents to slow or speed up the wheel. The actual speed of the wheel is detected and compared with a reference speed and the magnitude of the excitation currents is adjusted on the basis of the rotatory speed difference to effect the regulation of the speed of the chopper.