分别对有明显屈服和无明显屈服的材料进行室温、高温拉伸试验，对比了使用引伸计与未使用引伸计所测试的屈服强度的差异，同时结合力-变形曲线和力-位移曲线，探讨了使用引伸计和未使用引伸计测得的屈服强度不一致的原因。结果表明：室温拉伸实验时，对于无明显屈服的材料，装夹引伸计测得的屈服强度小于未装夹引伸计测得的；对于有明显屈服的材料，装夹引伸计与不装夹引伸计测得的屈服强度相差不大；高温拉伸实验时，无明显屈服的材料和有明显屈服的材料，在装夹引伸计时测得的屈服强度均小于不装夹引伸计时测得的。

The tensile tests at room temperature and high temperature were carried out for materials with obvious yield and no obvious yield. The yield strength measured by the extensometer and unused extensometer was compared. At the same time, combining the force-deformation curve and the force-displacement curve, the reasons for the difference of the yield strength measured by the extensometer and unused extensometer were discussed. The results show that the yield streghth measured by the clamped extensometer is less than that of the non-clamp extensometer for the materials with no obvious yield strength at room temperature tensile test. For the materials with obvious yield, the yield strength of the extensometer is similar to that of the non-clamp extensometer at room temperature tensile test. At high temperature tensile test, the yield strength of the materials with obvious or no obvious yield measured by the clamped extensometer is less than that of the non-clamp extensometer.