Detection of foreign matters and nanoparticles included in industrial and chemical products is an important application target for a sensor system. There is a need to detect a small piece of steel tool chipping or breakage included in the products nondestructively. A recent improvement of the manufacturing system strongly required an inspection of all items in every production process to realize the smart manufacturing system. A thin‐film magnetic field sensor is an impressive candidate for this target as it has an extremely high sensitivity, especially because it is driven by alternating current around hundreds of MHz, and it is also tolerant to a surface normal magnetic field due to its demagnetizing force in the thickness direction. In this study, the sensitivity of a sensor system that was created by applying a 0.3 T normal field to the detection area included in a sensor element and also by using a 400‐MHz high‐frequency driven thin‐film magnetoimpedance sensor was evaluated. An observation of the magnetic domain was also carried out at the same time as the sensitivity evaluation. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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薄膜磁阻传感器在0.3 T表面法向磁场中的灵敏度

工业和化学产品中包含的异物和纳米颗粒的检测是传感器系统的重要应用目标。需要无损地检测产品中包含的一小部分钢工具崩裂或破损。制造系统的最新改进强烈要求对每个生产过程中的所有项目进行检查，以实现智能制造系统。薄膜磁场传感器具有极高的灵敏度，尤其是因为它是由数百MHz左右的交流电驱动的，并且由于它的消磁性还可以承受表面法向磁场，因此它是该目标的理想选择。沿厚度方向的力。在这项研究中，通过应用0创建的传感器系统的灵敏度。评估了传感器元件中检测区域的3 T法向场，并通过使用400 MHz高频驱动薄膜磁阻传感器进行了评估。在进行灵敏度评估的同时，还进行了磁畴的观察。©2020日本电气工程师学会。由Wiley Periodicals LLC发布。