| 摘要 |
PURPOSE:To prevent the mixing-in of noises and improve the safety of the device by using a light transmitted by an optical fiber for supplying energy to an electronic circuit for excitation of a conductive wire capable of oscillation in a detecting part and for detecting the frequency of oscillation. CONSTITUTION:A light from a luminous element 29 is transmitted by the optical fiber 26 for a transmitting path from a light source, a solar cell 23 is driven and the output thereof is accumulated in an accumulator 24. The electronic circuit 22 delivers to the conductive wire 31, in accordance with the resonant characteristic of the wire 31, an oscillating current in the form of a rectangular wave whose frequency changes within the range of resonant frequency corresponding to the range of measurement of pressure to be measured. The conductive wire 31 gives rise to resonant oscillation and the oscillation is detected from the light between the light- emitting end 35 and light-receiving end 36 of an optical fiber 27. The received luminous energy of a photoreceiving element 30 changes in the form of a pulse, and by counting the number of the pulse, impressed pressure can be detected. |
