Patent ID: 6666094
Filing Date: 2003-12-23
Classification: B21B,G01B

Abstract:
A method for contactless online measuring of the wall thickness of hot-rolled pipes in the hot state for determining undesirable inner wall structures, the method comprising the steps of:scanning with at least one measuring head, operating according to the laser ultrasound method, a segment of a wall of a pipe to be measured in a circumferential direction during or directly after a rolling process; and reconstructing a course of the wall of a cross-section of the pipe with a computer, and wherein in the step of reconstructing mathematical analyses and symmetry considerations based on an inner polygon formation of the pipe are employed, wherein in the step of scanning several of the measuring heads are used, wherein the measuring heads are pivotable in the circumferential direction, and wherein each of the measuring heads scans a different allocated segment of the wall of the pipe, and wherein, for a maximum of four measuring heads distributed about the circumference of the pipe, at least one of the measuring heads is pivotable about an angular segment in the circumferential direction of the pipe, which angular segment is to be determined as a function of an expected order of the undesirable inner structure.