| 摘要 |
PURPOSE:To eliminate the need for washing of light transmission windows for a long period of time by making the normal angles to a light source on the light receiving surfaces of photodetectors which receive the emission light of the light source transmitted through sample water adjustable. CONSTITUTION:In measuring the org. polluting components in the sample water contg. org. polluting components and suspended aolid components, the light emitted from a light source L is irradiated toward the sample water W by way of a visible ray filter 10 and an ultraviolet ray filter 9 alternately by rotating a rotary chopper 8. Org. polluting components are determined from the respective outputs of the 1st and 2nd photodetectors D1, D2 provided at different optical path lengths at which the light transmitted through the sample water is received. At this time, the normal angles theta1, theta2 to the light source on the light receiving surfaces of the photodetectors D1, D2 are made adjustable, whereby the contamination compensating errors of the light transmission windows 11, 12, 13 of a light emitting part 3 and a photodetecting part 4 are improved, and maintenance characteristic, the long-term stability of measurement, etc. are improved. |
