| 摘要 |
PURPOSE:To enable measurement of the concn. of the solvent for electrodeposition painting stage in waste water by a UV absorptiometry by calculating the ratio between the output signals from the 1st detector and 2nd detector which detect the absorbances of the light having respectively specific wavelengths. CONSTITUTION:The 1st detector 18 of a measuring part 12 is constituted of an interference filter 22 which allows the transmission of UV light having 316nm wavelength and a photodetector 23 and the 2nd detector 19 is constituted of an interference filter 24 which allows the transmission of UV light having 254nm wavelength and a photodetector 25. Waste water 9 is cyclically supplied into a measuring tank 3 by a lifting pump 7. A low pressure mercury discharge tube 16 is lighted and the light transmitted through the waste water 9 is detected by the detectors 18, 19. The respective output signals are rectified in rectifier circuits 30, 31 via high-pass filters 28, 29 and the ratio between the signals is calculated in a calculator 33 and is outputted to an indicating part 14. The ratio of the absorbancy has a proportional relation in which said ratio increases with an increase in the concn. of a solent and the concn. of the solvent in the waste water is known from said ratio. |
