| 摘要 |
PURPOSE:To enable accurate measurement of elongation or the difference in elongation by meas of a simple structure by a method wherein a group of the bundles of photofibers composed of photofibers for transmission and reception is arranged in opposition to a nonphotoreflecting zone provided in a rotary body and relative displacement in position of the bundles of photofibers and the nonphotoreflecting zone is detected. CONSTITUTION:The photofiber 3 for transmission located in the center and the photofiber 4 for receiving light surrounding the former constitute the bundle 2 of photofibers, which is arranged in a row in opposition to the nonreflecting zone 8 of the rotary body 5. The light 9 from a light source 6 falls on the rotary body 5 through the photofibers 3 for transmission of the bundle 2 of photofibers and the reflected light 10 enters a receiver 7 through the photofibers 4 for reception. In accordance with the relative displacement in position of the nonreflecting zone 8 and the bundle 2 of photofibers, the elongation or the difference in elongation of the rotary body 5 is measured by the receiver 7. By this constitution, accurate measurement of the elongation or the difference in elongation can be performed by means of a simple structure. |
