利用Fe-Ga磁特性测试装置进行动态磁致伸缩测量时, 受激励线圈产生的磁场的影响, 测试样品的应变通常偏大, 本文对此做了分析并进行验证。通过分析Fe-Ga动态磁致伸缩测量过程, 对原测试装置进行了改进。将样品的一端固定在极头上并调节激励磁场使其在样品饱和磁场附近, 以消除机械振动对动态磁致伸缩测试产生的影响。采用多参数磁学测试系统和改进前后的Fe-Ga特性测试系统进行Fe-Ga静态和动态磁致伸缩特性测试实验。结果表明: 采用改进的Fe-Ga磁特性测试装置可在低饱和场下精确测量动态应变。实验还测试了Fe-Ga在2.7 kA/m偏置磁场作用下的动态磁致伸缩特性, 结果表明: （1）偏置磁场作用下应变与磁场同频; （2）应变对磁场的滞后随磁场频率的增加而增大; （3）λ～H曲线为椭圆形且椭圆环的面积随频率的增大而增大。上述结果表明, 本文提出的改进装置可有效消除振动产生的额外应变。

Due to the influence of vibration caused by magnetic field of excitation coil, the strain measured by test device of Fe-Ga magnetic characteristics is usually larger than actual one. This paper explained and verified the above phenomenon. By analysis the measurement process of dynamic magnetostrictive strain of Fe-Ga alloy, the original testing device was improved by fixing one end of the sample on pole head and adjusting excitation magnetic field near saturated magnetic field of the sample, resulting in error caused by mechanical vibration on the test of dynamic magnetostriction was eliminated. Static and dynamic magnetostriction test experiment were conducted by adopting multi-parameter magnetic test system and original and improved test device of Fe-Ga magnetic characteristics. Experimental result indicates that the improved test device of Fe-Ga magnetic characteristics has the ability to accurately measure the dynamic magnetostriction of sample with low saturated magnetic field. Dynamic magnetostriction of Fe-Ga at the effect of bias magnetic field of 2.7 kA/m was also tested in the experiment, and the result indicates: (1) the frequency of strain is the same as that of magnetic field at the effect of bias magnetic field; (2) the hysteresis of strain on the field increases with increase of field frequency; (3) λ～H curve is of elliptical and the area increases with increase of the frequency. The proposed improved device can effectively eliminate the strain caused by vibration.