| 摘要 |
An optical sensing system comprises an optical fibre (7) provided with at least three reflecting elements (A, B, C, D, E) spaced along the fibre. A coherent light source (1) is arranged to supply a light pulse train to the fibre. A detector (4) is arranged to compare reflected light pulses from two of the light reflecting elements to provide a signal representative of fibre deforming forces occuring between the two reflecting elements. A selector (6) is provided which enables selection for comparison of reflections from a chosen two of the reflectors thereby determining the length of fibre used to provide the signal which is sensed. |
