中文摘要：

为提高涡流检测建模的精度,需要测量铁磁性金属材料的低频磁导率曲线。本文采用示波器法对10Hz下45钢的磁导率曲线进行了测量。首先通过分析测量原理,确定了积分电路性能是影响测量结果的主要因素之一。接着采用传统RC积分电路进行了测量实验,实验结果误差偏大,指出了误差来源。随后,分析了运放积分的优点,设计了基于LF356N的积分电路并用其替换RC积分电路进行实验,测量结果合理,准确性好。研究成果对铁磁性金属材料低频磁导率的测量工作具有一定的实验指导意义。

英文摘要：

To improve the modeling accuracy for eddy current testing, it is necessary to measure the magnetic permeability of ferromagnetic metallic materials at low frequencies. In this paper, the permeability curve of 45 steel at 10 Hz was measured with the oscillograph method. First, by analyzing the principle of measurement, it was found that the performance of the integrating circuit is one of the main factors affecting measurement results. Then, experiment was carried out by using a traditional RC integrator, the experimental error was large and its sources were analyzed. Afterwards, the advantages of operational-amplifier based integrating circuit were analyzed and an integrator based on LF356N was designed. By using the designed integrator, experiment was carried out again and results turned out to be reasonable and of high accuracy. The presented research will benefit the experiment measurement of magnetic permeability of ferromagnetic metallic materials at low frequencies.