IPC-TM-650 2.4.25 Glass Transition Temperature and Cure Factor by DSC 中: 5.4 Determination of Tg The glass transition temperature is determined by a construction procedure on the heat flow curve. 5.4.1 Construct a tangent line to the curve above the transition region and a second tangent line to the curve below the transition region. 5.4.2 The temperature on the curve halfway between the two tangent lines, or 1/2 delta Cp, is the Tg. 其中halfway是半高还是半宽? 是起始切点的到终止切点的半高/半宽,还是起始点和终止点的半高/半宽?