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:
Feb. 11, 2003
Filed:
Nov. 12, 1999
Nippon Sanso Corporation, Tokyo, JP;
Abstract
A gas spectroscopic analysis device for analyzing a trace impurity in a sample gas by obtaining the second derivative spectrum of the light absorption intensity by passing frequency modulated diode laser light through a low-pressure sample gas is provided with a modulation amplitude calculating device ( ) for controlling the modulation amplitude of the laser light in accordance with the characteristics of diode laser ( ); a spectrum calculating device ( ) for calculating the peak absorption intensity and the wavelength interval between the minimum values on the left and right hand of the peak in the second derivative spectrum obtained by measurement; and a pressure adjusting device ( ) for controlling the pressure inside measuring gas-cell ( ) so that the value of the absorption intensity obtained at spectrum calculating device ( ) becomes maximal. The optimal value of the modulation amplitude of the laser light is set so that the wavelength interval between the minimum values on the left and right hand of the peak in the second derivative spectrum is 0.0116 nm. The measurement pressure is optimized by setting the modulation amplitude to an optimal value.