INSTRUMENT FOR MEASURING WALL THICKNESS OF CORRUGATED PIPE

摘要

PURPOSE:To continuously measure the wall thickness of a corrugated pipe accurately in an on-line state by positioning the probe of an ultrasonic measuring instrument and detector of a discriminating means in a specific positional relation with each other in a state where they are faced to the corrugated pipe moved in the axial direction. CONSTITUTION:Ultrasonic pulses radiated from the probe 21 of a ultrasonic measuring instrument 20 on a corrugated pipe 3 are received by the instrument 20 after the pulses are reflected by the outer and inner peripheral surfaces of the pipe 3 and an output signal corresponding to the receiving time interval between both echoes is outputted from the instrument 20. As the pipe 3 is moved in the axial direction, the angle between the peripheral surface of the pipe 3 and probe 21 varies and significant and insignificant outputs are sent from the instrument in a mixed state. Moreover, to which part of the pipe 3 the probe 21 of the instrument 20 is faced and whether the probe 21 is faced to the flat section of the crest section 3a or that of the trough section 3b of the pipe 3 are discriminated by means of a sensor group 31a, 31b, 32a, and 32b. Moreover, the output of the instrument 20 is discriminated as significant and the wall thickness of the pipe 3 is measured while the probe 21 is orthogonal to the peripheral surface of the pipe 3.