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:
Apr. 05, 1994
Filed:
Mar. 26, 1992
Applicant:
Inventor:
Edmund Koch, Lubeck, DE;
Assignee:
Dragerwerk Aktiengesellschaft, Lubeck, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; G01N / ;
U.S. Cl.
CPC ...
356437 ; 250343 ; 250345 ;
Abstract
An arrangement for making gas spectroscopic measurements includes a laser diode driven by a modulated control current, a monitor diode, a detector unit for receiving a measurement signal of the transmitted radiation and a lock-in amplifier. The method utilizing the above arrangement is improved in that the offset component in the output signal of the lock-in amplifier is eliminated. This is achieved in that the radiation power of the laser diode is controlled to a pregiven modulation profile with the monitor diode functioning as an actual-value transducer.