| 摘要 |
PURPOSE:To make it possible to perform high-fidelity measurement without the effect of electromagnetic induction, by coupling a vibration detecting part and a main body by optical fiber. CONSTITUTION:Light generated by a light emitting element 8 is inputted to an end surface K of a sending optical fiber 5 and propagated in the optical fiber 5. Projecting light 14 emitted from an end surface D of the optical fiber 5 on the side of a mirror is projected on a vibrating plate 4. The back surface of the vibrating plate 4 is a mirror. Part of the reflected light 15 from the mirror surface is inputted to an end surface E of a returning optical fiber 6 on the mirror side. The intensity of the light inputted in the optical fiber 6 is different depending on the displacement of the vibrating plate 4. Namely, the displacement signal of the vibrating plate is converted into the light intensity. The returning light transmitted through the optical fiber 6 is outputted from the other end L and inputted to a light receiving element 9 in a receiving part R. The light is converted into an electric signal in correspondence with the light intensity by the element 9. A desired electric signal is obtained by an amplifier 10. An equalizer 11 is provided at the following stage of the amplifier, as required. |
