MEASURING METHOD FOR THICKNESS OF TUBULAR MATERIAL

PURPOSE:To measure the thickness of a pipe effectively even when it is rotating or running, by measuring the positions of the external and internal diameters of the pipe actually at the same time by using a photoelectric detector having a high response speed and a beam position measuring instrument. CONSTITUTION:For the measurement of the thickness of, for example, a seamless steel pipe 1 in rotating or running motion, a container 4 containing a radiation source 3 and a frame 9 supporting a radiation beam detector 10 are driven as shown by an arrow 12 or 13 by a motor 7 through a rack 5 couled with the frame 9 and a pinion 6. With a radiation beam 2 entering the detector 10 through collimators 8 and 8a, the internal diameter position L2 of the pipe 1 corresponding to a reference point S2 is measured through a linear scale 25 and a pointer 26. Simultaneously, the internal diameter position L10 corresponding to a reference point S1 is measured by detecting the self-emitted light of the pipe by a photoelectric detecror 11 driven by a motor 7a. Consequently, the thickness of the pipe 1 in rotating or running motion is meaured effectively.