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:
Jun. 05, 1979
Filed:
Mar. 20, 1978
Mitsuo Kotaka, Musashino, JP;
Hisao Takahara, Musashino, JP;
Kaisuke Muraki, Musashino, JP;
Ryo Takahashi, Musashino, JP;
Tamizo Matsuura, Musashino, JP;
Yokogawa Electric Works, Ltd., Tokyo, JP;
Abstract
To detect the density of a measurement component of a sample gas, infrared light is directed alternately through a measuring-light optical system and a reference-light optical system to a heated light sensor. The measuring-light optical system includes a sample cell, a first filter for transmitting infrared rays of a fixed wave-length band, and a temperature compensating cell having a gas which has a part of its absorption wave-length band within the transmission wave-length band of the first filter but has a spectrum different from the spectrum of the measurement component. The reference-light optical system includes a light throttle, an interference cell having a gas containing a fixed density of the measurement component, an adjustable-length interference compensating cell filled with the sample gas, and a second filter for transmitting rays of a wave-length band that includes the major part of the transmission wave-length band of the first filter. The compensating cell is set such that, with temperature fluctuations, variations in absorption by the temperature compensating cell in the wave-length band of the first filter are equal to variations in absorption by the interference cell within the wave-length band of the second filter.