| 摘要 |
PURPOSE:To compensate automatically the error owing to mixing of signals with each other by measuring and storing the output of contrast light when the contrast light is shielded and the output from a filter for selecting the detection signal of sample light when the sample light is shielded and subjecting the photodetection signals of the contrast light and the sample light to correction and operation. CONSTITUTION:A chopper 1 is stopped in the position where contrast light is shielded and a chopper 2 is rotated to chop sample light at a prescribed frequency f2. The detection signal Pr' of the contrast light and the detection signal Ps' of the sample light in this stage are determined, then the ratio Kr at which the detection signal of the contrast light mixes with the detection signal of the sample light is determined. A microprocessor 18, which has the program to determine Kr, Ks and the program to calculate So, Ro by making correction and operation in the stage of measurement, determines Pr and Ps by driving a spectroscope 6 and performing wavelength scanning, stores the same into a memory M, reads out Pr and Ps upon termination of scanning, makes correction and operation to calculate Ro and So and outputs transmissivity So/Ro to a display device 23 to have the same recorded. |
