| 摘要 |
PURPOSE:To enable to perform an average and easy detection of a load applied to a wide area, by a method wherein a plural number of circular holes is machined in an iron block, and a strain-detecting optical fiber and a dummy fiber are attached in a spiral therein to use them as detecting means. CONSTITUTION:A plural number of circular holes 10 are formed in an iron block 9, and a strain-detecting optical fiber 4 is attached in a spiral to the inner wall thereof so that it deforms corresponding to the deformation of the circular hole 10 due to an external force. Meanwhile, a dummy fiber 5 is attached in a spiral to the inside of the circular hole 10 so that it is brought to a free state, under which it is prevented from being influenced by the deformation of the circular hole 10, or it performs an opposite deformation to that of the strain-detecting optical fiber 4. Laser light is caused to simultaneously enter the two fibers 4 and 5 through the ends at one side thereof, and an external force is detected from movement of an interference fringe created due to interference of the two lights radiated through the ends at the other side. |
