| 摘要 |
PURPOSE:To eliminate measuring errors, by changing the detection signal of a photoelectric converter for detecting one branched light with a beam splitter and the detection signal of a photoelectric converter for detecting the other branched light delayed with an optical fiber to be converted alternately using a set of A/D converter. CONSTITUTION:The light transmitted with an optical fiber is delayed in proportion to the length of the optical fiber. Out of the branched light from a light sensor 1 with a beam splitter 2, the light passing through optical fibers 4a and 4b is delayed. So, a selector switch 2 is used to change the signals of the non-delayed light and the signal of the light delayed alternately to be inputted into an A/D converter 9. This requires only one converter 9 thereby eliminating measuring errors due to the difference in the A/D converter characteristic that would be caused in the use of a plurality of A/D converters. |
