采用不同同轴度的拉伸试验机，对比了单侧引伸计和双侧引伸计测量金属材料弹性模量的结果。结果表明：同轴度对金属材料弹性模量测量的影响较大，且对采用单侧引伸计测量弹性模量的影响更为显著，建议采用双侧引伸计测量弹性模量。建议GB/T 228.1-2010修订时充分考虑拉伸试验机的同轴度对弹性模量测量的影响。

The results of elastic modulus measured by unilateral extensometer and bilateral extensometer were compared by using tensile test machines with different coaxiality. The results show that the coaxiality had a great influence on the measurement of elastic modulus of metal materials, especially on the measurement of elastic modulus with unilateral extensometer. It is suggested to use bilateral extensometer to measure elastic modulus. It is suggested that the coaxiality of tensile test machine should be fully considered when GB/T 228. 1-2010 is revised.