磁致伸缩系数定义为磁性材料在外磁场作用下产生的长度或体积的相对变化量,是磁性材料基本特性参数之一。因此,准确地测量磁致伸缩系数对研究磁性材料有重要意义。由于Mn-Zn铁氧体的磁致伸缩系数在10~(-7)～10~(-3)范围内,故必须采用高灵敏度的测量方法。本文所介绍的自动测量系统,其灵敏度达到2×10~(-3),在12秒钟内自动描绘出λ-H曲线,而且测试操作方便。对于磁致伸缩系数λ≥20×10~(-3)的测量,误差小于±13%,测量数据重复性好。在室温至70℃范围内,可测量磁致伸缩系数λ随温度T的变化。 Magnetostrictive coefficient is defined as the magnetic material in the external magnetic field generated by the relative length or volume changes, is one of the basic characteristics of magnetic materials. Therefore, accurate measurement of magnetostriction coefficient is of great significance for the study of magnetic materials. Since the magnetostriction coefficient of Mn-Zn ferrite is in the range of 10 -7 to 10 -3, it is necessary to adopt a highly sensitive measuring method. The automatic measurement system introduced in this paper has a sensitivity of 2 × 10 -3, automatically plotting the λ-H curve within 12 seconds, and the test operation is convenient. For the measurement of magnetostriction coefficient λ≥20 × 10 -3, the error is less than ± 13%, and the measurement data is good repeatability. In the range of room temperature to 70 ° C, the change of the magnetostriction coefficient λ with temperature T can be measured.