7.7.2 Extension-Under-Load Method—Yield strength by the extension-under-load method may be determined by: ( 1) using autographic or numerical devices to secure stress-strain data, and then analyzing this data (graphically or using automated methods) to determine the stress value at the specified value of extension, or ( 2) using devices that indicate when the specified extension occurs, so that the stress then occurring may be ascertained (Note 30). Any of these devices may be automatic. This method is illustrated in Fig. 22. The stress at the specified extension shall be reported as follows: