The speed may be increased after removal of the
extensometer, but it shall not exceed 0.5 in./in. of gage length
(or distance between grips for specimens not having reduced
sections) per minute,如上这是铝合金ASTM B557里关于拉伸测试过了屈服阶段的速度,比如我的产品标距是2英寸,那速度该设为多少,是0.5x2=1/min 还是 0.5/2=0.25/min?