| 摘要 |
PURPOSE:To prevent the characteristics of an interference filter from being changed by the temperature change by altering and inserting an interference filter of which characteristics are changed in accordance with temperature into a photometric path only at the time other than photometric operation. CONSTITUTION:Light emitted from a light source 2 in a lamp house 1 is irradiated to solution 11 to be detected in a cuvette 10 through a lens 3, an interference filter 4, a reflector 8, and a lens 12 and received by a photodetector 13 to measure the absorbance of the solution 11 to be detected and check the response status of the solution 11. Plural interference filters 4 passing luminous flux with various wavelengths are set up on an interference filter holding member 5, which arranges a prescribed interference filter on the light path by the operation of a driving mechanism 7. At no photometric operation, the interferance filter is changed and inserted into the optical path while the light source 2 is on. Thus, the temperature of an interference filter is kept constantly, reducing the change of characteristics. |
