METHOD FOR IDENTIFYING COATED FIBER OF OPTICAL FIBER AND MEASURING LEVEL IN FIBER

摘要

PURPOSE:To shorten the time for decision in identification of a coated fiber by making decision that the coated fiber is identified when the output of an A/D converter is larger than the threshold if the gain of a gain switching amplifier is max. and as it is if the gain is smaller than the max. CONSTITUTION:A fiber set detecting switch SW is provided in a detector 14 designed to pinch and hold the coated optical fiber from above and below and is so constituted as to detect the coated optical fiber set when the fiber is set in the detector 14 and to transmit the detection output thereof to a CPU 16. The output of a comparator 27 is sampled and stored at specified intervals when the coated optical fiber is detected in the detector 14. The amplification factor of the gain switching amplifier 23 is lowered if there is the output of the comparator 27. The amplification factor is raised when there is no output. Decision is made that the coated fiber is identified when the output of the A/D converter 26 is larger than the threshold if the gain of the amplifier 23 is the max. Decision is made that the coated fiber is identified as it is if the gain of the amplifier 23 is smaller than the max.