| 摘要 |
<p>PURPOSE:To conduct proper detection by executing an arithmetic processing wherein the square of an IN output obtained through an optical fiber for N (light-sensing position near to a light source) is divided by an IF output obtained through an optical fiber for F (light-sensing position far from the light source). CONSTITUTION:An output signal obtained by photoelectric conversion in a light-sensing element 5c for a light source is amplified 21, compared 22 with a reference value and outputted as a light quantity control signal for the light source to a light source driving circuit 23. A power controlled properly in this circuit 23 is sent to infrared LED 20 and an appropriate quantity of light is emitted therefrom. Then, a part of the flux of light emitted through a bundle optical fiber 13 for the light source is made to enter an element 5c, while the other part thereof is projected from an end face 12a of a bundle optical fiber body 12 into water 3 to be inspected. This projected light is absorbed or scattered by particles 2 of a suspended substance and a reflected light therefrom enters bundle optical fibers 14 and 16 for N and F. Lights entering the optical fibers 14 and 16 are subjected to photoelectric conversion in light-sensing elements 5a and 5b for N and F, amplified 24, 26 and inputted as outputs IN and IF to an arithmetic circuit 25. An arithmetic processing of IN<2>/IF is executed in the circuit 25 and the result is outputted 27.</p> |
