ELONGATION MEASURING METHOD AND DEVICE FOR TEST PIECE

摘要

PROBLEM TO BE SOLVED: To provide a non-contact elongation measuring method and device capable of obtaining an accurate measured value without a marked line and being automated. ;SOLUTION: A laser beam is emitted to marked line assumed positions in two portions of a test piece from two sensor parts formed by a laser projector and a CCD camera. The respective laser reflected beams are individually image picked up as a speckle pattern formed by many stripes by the CCD cameras, stripes in specified positions of the respective speckle patterns are recognized as a target corresponding to each of two marked line assumed positions on the coordinates of the screen of the CCD camera, and the picture element unit moving amount on the coordinates of each target stripe moving with elongation of the test piece is detected to obtain elongation information on the test piece. The stripes of the speckle pattern image picked up by the CCD camera may be image-converted to a mark in each specified position of a television camera screen. The image standstill or turbulence of an image of the speckle pattern of the CCD camera appearing immediately before the test piece is cut may be sensed to stop the tensile load of the test piece.;COPYRIGHT: (C)2001,JPO