METHOD FOR MEASURING END-MARK OF TEST-PIECE

摘要

A method for measuring the defect of a test piece is provided to measure an end mark formed in the test piece accurately by irradiating a laser beam on the test piece and measuring the holographic of the test piece. A method for measuring the defect of a test piece comprises: a step(S120) collecting a test piece from a steel sheet reeled in a winding reel; a step(S140) transferring the test piece to prevent curvature formed in picking the test piece from being changed; a step(S160) mounting the test piece on a clamping unit in order to remove the curvature formed in picking test piece; and a step(S180) irradiating the laser beam on the surface of the test piece and measuring the defect of the test piece. In the test piece, a floor side is built up. The floor side is formed with the curvature formed in picking test piece. The test piece is collected from the steel sheet reeled on the top of the steel sheet contacted with the outer circumference of the winding reel.