| 摘要 |
PURPOSE:To prevent reception of an influence from a thunderbolt or a noise by executing signal transmission between a water level detector and a receiver and the supply of energy, which is needed for the water level detector, by the optical fiber cable of one core. CONSTITUTION:A water level signal, which is a measuring subject, is transmitted to a measuring circuit 5 by a water level detecting mechanism 4 and mechanical displacing quantity is converted to an electric signal and sent to an electrooptical converter 6. In the electrooptical converter 6, the electric signal is further converted to the optical signal of a frequency f2 and sent through an optical fiber 3 to a photoelectric converter 7 in the internal part of a receiver 2. Then, the optical signal is converted to the electric signal and after that, it is restored to the water level signal by a decoder 8. Electric energy P to be needed in the internal part of the water level detector 1 is converted to the optical energy of a frequency f1 from a power source 9 in the internal part of the receiver 2 by an electrooptical converter 10. After that, the energy is passed through the optical fiber 3, converted again to the electric energy by a photoelectric converter 11 and supplied from a power source circuit 12 to respective parts. Thus, the water level can be measured without being affected by the thunderbolt or noise. |
