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:
Aug. 13, 2013
Filed:
Jul. 22, 2011
Yousuke Hoshino, Nakano-ku, JP;
Kenji Takubo, Uji, JP;
Naoji Moriya, Nara, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
A gas concentration measurement device which utilizes a TDLAS measurement method, and in which the phase-sensitive detection can be performed by digital processing using an integer-arithmetic device, is provided. In the gas concentration measurement device according to the present invention, AC components corresponding to integer multiples of a modulation frequency f contained in an input signal are removed by taking a moving average of data obtained from an output signal of a multiplierfor a period of time corresponding to one cycle of the modulation frequency f . As a result, a DC component in the output signal of a digital filterrelatively increases, making it easier to extract the DC component by a digital low-pass filter, so that a sufficiently accurate phase-sensitive detection can be made even if a digital processing based on integer arithmetic is used.