| 摘要 |
PURPOSE:To enable automatic detection of a yield elongation, by providing a load detector, an elongation detector, buffer, a differentiation device, an arithmetic unit and the like. CONSTITUTION:A load detector 1, an elongation detector 2, a lock generator 3, a buffer 4, an arithmetic unit 6, a printer 7 and the like are provided. Then, the differentiated value of the average load near the point E is determined to be represented by a1. Then, the differentiated value is searched oppositely from the point E to the point A to determine the point C where the value becomes minus for the first time. Then, changes al-bi in the differentiated value is searched from the point E to the point C, where bi represents the differentiated value at a certain time (i) Then, when a1-bi>X, the elongation corresponding to the time (i) shall be the end point of the yield elongation. Here, X represents variables which are set smaller sequentially from a value larger than the fall F of the estimated differentiated value at the end point of the yield elongation to the minimum fall predetermined. Thus, the yield elongation can be detected automatically. |
