| 摘要 |
PURPOSE:To enhance S/N of chromatogram and the like obtained based on a signal having a small amplitude, by changing the amplification factor of an amplifier in correspondence with the movement of a reflecting mirror in a Michelson interferometer. CONSTITUTION:Infrared light from a light source 1 is imparted to a Michelson interferometer provided with a movable moving mirror 6. The output light from the interferometer 3 is detected by a detector 11. Meanwhile, gas from a gas- chromatograph 13 is supplied to the detector 11. Then, the output of the detector 11 is imparted to an amplifier 16 or 17 through a switch 15. The output is supplied to a CPU20 through an A/D converter 19, and an operation such as Fourier transformation is carried out. At this time, the amplifiers 16 and 17 are selected by the movement of the moving mirror 6. Therefore, the amplification factor of the output of the detector 11 can be changed. Thus the S/N of chromatogram and the like, which are obtained based on the signal having a small amplitude can be enhanced. |
