| 摘要 |
PURPOSE:To remove indication drifts in principle due to contamination of cell window and deterioration of luminous source by causing the known reference sample and a sample to be measured to alternately flow to a measuring cell thereby to process the output obtained. CONSTITUTION:Light emitted from a luminous source 1 passes through the sample within a cell 2 to cause photo absorption, and a measuring wavelength is selected by an interference filter 8 and the light is received by a detector 9. Since the reference sample Z and the sample to be measured S alternately flow, variation of photo absorption due to both samples occurs in a predetermined period. The detector 9 detects an AC waveform close to a sin wave. The output of the detector 9 is added to a meter 14 by way of a preamplifier 11 and further an AC amplifier 12 and a rectifier 13. |
