公开(公告)号：CA2715157A1

公开(公告)日：2009-08-20

申请号：CA2715157

申请日：2008-02-15

Applicant: STFC SCIENCE & TECHNOLOGY

Inventor： WEIDMANN DAMIEN

IPC: G01J3/42 ,  G01J3/08 ,  G01N21/27 ,  G01N21/35 ,  G01N21/39

Abstract: Method and apparatus for detecting, by absorption spectroscopy, an isotopic ratio of a sample, by passing first and second laser beams of different frequencies through the sample. Two IR absorption cells are used, a first containing a reference gas of known isotopic ratio and the second containing a sample of unknown isotopic ratio. An interlacer or reflective chopper may be used so that as the laser frequencies are scanned the absorption of the sample cell and the reference cell are detected alternately. This ensures that the apparatus is continuously calibrated and rejects the baseline noise when phase sensitive detection is used.

公开(公告)号：CA2715157C

公开(公告)日：2015-05-12

申请号：CA2715157

申请日：2008-02-15

Applicant: STFC SCIENCE & TECHNOLOGY

Inventor： WEIDMANN DAMIEN

IPC: G01J3/427 ,  G01J3/08 ,  G01J3/10 ,  G01N21/39

Abstract: Method and apparatus for detecting, by absorption spectroscopy, an isotopic ratio of a sample, by passing first and second laser beams of different frequencies through the sample. Two IR absorption cells are used, a first containing a reference gas of known isotopic ratio and the second containing a sample of unknown isotopic ratio. An interlacer or reflective chopper may be used so that as the laser frequencies are scanned the absorption of the sample cell and the reference cell are detected alternately. This ensures that the apparatus is continuously calibrated and rejects the baseline noise when phase sensitive detection is used.