公开(公告)号：US3590255A

公开(公告)日：1971-06-29

申请号：US3590255D

申请日：1969-02-28

Applicant: INSTRUMENTATION LABOR INC

Inventor： SMITH STANLEY B JR ,  BURNETT JAMES E

IPC: G01N21/31 ,  G01N21/26

CPC classification number: G01N21/3103

Abstract: An analysis system includes an analysis cell and a radiation source which generates a characteristic radiation. An optical system passes radiation from the source along a first path through the analysis cell for sensing by a sensor and passes radiation from the source along a second path outside of the analysis cell, for sensing by a second sensor. An optical modulator channels the radiation in each path alternately to the sensors so that each sensor alternately produces an output proportional to the radiation from the corresponding source in each path and means responsive to the optical modulator provides an accurately predetermined portion of the output signal from each sensor in each cycle of the optical modulator.