| 摘要 |
<p>Optical sensing apparatus for measuring quantities such as a displacement, pressure, electric voltage or field, and magnetic current or field, wherein errors due to fluctuations in the outputs of light sources and transmission losses of optical fibers are eliminated. First and second light sources (1-1, 1-2) are alternately activated, and ratios of their outputs are determined in both cases. Then, the ratio of these two outputs is calculated (calculator 20) to thereby provide a signal representing the quantity being measured. The optical sensing equipment is arranged such that terms affected by fluctuations in the outputs of the light sources and transmission losses in optical fibers (2-1, 2-2) used in the optical sensing equipment cancel out in the divisions providing the three ratios. </p> |
