PURPOSE: To prevent the deposition of foreign matter and slime in a liquid to be measured by providing a radiation window and a photoreceiving window to the pipe wall of a conduit flowing the liquid to be measured.
CONSTITUTION: A radiation window 2 and a photoreceiving window 4 are provided to the pipe wall of a conduit 10. Thereby, the contact part with the liquid 3 to be measured becomes the min. and also the washing effect to a deposited material and foreign matter at the contact surface can be expected due to the flow speed of the liquid 3, and a long time preservation of the measuring performance and maintenance checking frequency can be improved remarkably Only the windows 2 and 4 are provided to the inner wall of the conduit 10 of the liquid 3, the optical systems such as a light source lamp 1 and a detector 5 are provided to the outer part of the conduit 10. Thus, checking and repair of the optical system such as exchanges of the lamp 1 and the detector 5 become easy, thereby improving remarkably in economical a spact.
TONEGAWA HISASHI
SASAKI TOSHIHIKO
TAKASHIMA KAZUO
NAKAHORI ICHIROU
MAEDA MITSUO
