| 摘要 |
PURPOSE:To shorten the measuring time and to improve the measuring precision by changing over alternately a sample light intensity signal and a reference light intensity signal with electric signal change-over means and AC amplifying the output. CONSTITUTION:The sample light intensity signal S and the reference light intensity signal R detected respectively by detectors 5A, 5B are applied to the electric signal change-over means 7 through preamplifiers 6A, 6B respectively. The intensity signals S, R changed over alternately by the means 7 are amplified logarithmically by a log amplifier 9, and the AC component is AC amplified by a main amplifier 10. Next, the output of the amplifier 10 is rectfied by a synchronous rectifier 11, and then recorded in a recorder 12. Since the signal is changed over by the means 7 at high speed in such a way, the measuring time can be shortened. Since it is not influenced by low frequency noise and drift basing on the AC amplifying, the measuring precision can be improved. |
