JPS6488307A - Oxide film measuring instrument for fuel channel - Google Patents

Abstract

PURPOSE:To accurately and easily perform measurement at many measurement points in a short time by holding a film thickness measurement sensor by holders provided on respective side walls of a support frame into which the fuel channel is inserted vertically. CONSTITUTION:The fuel channel NC2 is lowered by a suspender 12 and inserted into the support frame 3, and then the channel is stopped at a specific measurement position; and a cylinder body 8 is moved forth by being driven by an air cylinder 6 to press the tip part of the film thickness measurement sensor 5 against the external surface of the NC2 through compression springs 44 and 43, etc. Then the thickness of the oxide film of the NC2 is measured by eight sensors 5 arranged in a circumferential direction at the same time under the control of a controller 13. Then the sensors 5 are moved back 6, the NC2 is moved 12 up and down to a next measurement position, and film thickness measurement 5 is performed similarly. Similarly, the film thickness measurement is performed at eight positions in the same direction at the same time by each lengthwise position of the NC2. Thus, the tip of the sensor 5 slants so as to come into surface contact with the external surface of the NC2 and is pressed almost constantly to measure the film thickness by each sensor 5.