| 摘要 |
PURPOSE:To enable to perform a reliable and high-precise detection of irregularity of fiber bundle by a method wherein a correction is made so as to deduct the influence which a change in environmental condition exerts on a change in drift. CONSTITUTION:An electrostatic capacity detector 11 causes an electrostatic capacity to change in proportion to a mass at a time when a fiber bundle 1 is inserted between electrodes 11a and 11b, and an oscillating circuit 12 allows an oscillating frequency to change corresponding to a change in capacity thereof. An output of a frequency - voltage converter 13 is inputted to a buffer amplifying circuit 14, the output of the circuit 14 is led out as the mass change detecting signal of the fiber bundle, and simultaneously, it is inputted as a negative feedback to a mixing circuit 13a through a self-frequency microadjusting circuit 20. A compensating gradient setter 17, which obtains a signal from a detecting means 15 for environment such as temperature, applies its output to an adding circut 24, and causes a change, an oscillating frequency of a local oscillating circuit 25. This performs a correction so as to deduct the influence which a change in environmental condition exerts on an output of a drift. |
