| 摘要 |
PURPOSE:To make possible the long-term stable measurement with high accuracy by packing a sample into the length of a sample optical path, changing the passed photocurrent and optical path length in this stage and making measurement from the difference between the optical path length and the passed photocurrent in this stage. CONSTITUTION:The light emitted from a light source 1 passes through an optical window 2 then through a sample absorption chamber 3 filled with ozone. The light attenuated there passes through an optical window 4 and enters a phototube 5 by which the light is converted to photocurrent. The photocurrent is amplified 7 and is converted to a voltage which is stored 8. The optical window 4 and the photoelectric tube 5 are moved by a cylinder 6 up to the intermediate of the optical path length TS and stop. The photocurrent in this stage is the photocurrent increased from the previous photocurrent. Such photocurrent is stored 8'. The reference photocurrent is the value obtd. by doubling the difference between the previous two currents and adding the photocurrent in the stage of the optical path length TS. The density is then obtd. by a calculator 9. Since the same optical system and detecting system are used in the above-mentioned manner, the fluctuation of a detector or the like by the deterioration of the light source of the like is obviated. |
