| 摘要 |
PURPOSE:To secure a high-sensitivity detection for the position of the information medium by providing each detection part to the transmitter of the optical signal featuring plural different central wavelengths in correspondence to each central wavelength and then varying the specified wavelength through each detection part owing to the presence of the information medium. CONSTITUTION:No leaked substance which becomes to be the information medium comes in form fluid transport path 1 to each of detection parts 71-7n of optical transmission line 4 as far as path 1 has no leak trouble. As a result, no change is caused to the optical signal transmitted to light reception part 6 from light transmission part 5 to display the normal state at part 6. In case the leak trouble occurs at, for example, detection section l1, optical filter 10 intrudes into detection part 71 by the weight of the leaked substance. As a result, only central wavelength lambda1 has a change, and wave lambda1 enters receiver 61 with the optical level change. Thus this state is analyzed at receiver 61 to show the presence of the leaked substance at section l1. In such way, the presence and the position of the information medium, i.e., the leaked substance can be detected in a high sensitivity. |
