A food contaminant detection system based on high-Tc SQUIDs
A food contaminant detection system based on high-Tc SQUIDs
复制标题
基于高温SQUID的食品污染物检测系统
DOI：
10.1088/0953-2048/19/5/s24
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发表时间：
2006
影响因子：
3.6
通讯作者：
S. Suzuki
中科院分区：
文献类型：
--
作者：
Saburo Tanaka;H. Fujita;Y. Hatsukade;T. Nagaishi;K. Nishi;H. Ota;T. Otani;S. Suzuki
基于高温超导量子干涉仪（SQUID）探测器，我们设计并构建了一套计算机控制的食品污染物检测系统。该系统采用防水不锈钢结构，符合HACCP（危害分析和关键控制点）计划指南。该系统的外部尺寸为1500 mm长× 477 mm宽× 1445 mm高，可容纳200 mm宽× 80 mm高的物体。在标准型号中安装了自动液氮填充系统。该系统采用厚度为1 mm的双层可渗透金属屏蔽作为磁屏蔽盒。利用有限元法模拟了箱体内的磁场分布，并在制作前对各屏蔽层之间的差距进行了优化。在Z分量中实现了732的屏蔽因子。该值足够高以在非实验室环境中安全地操作系统，即，一家工厂在测试过程中，我们成功地在75 mm的距离上检测到直径小至0.3 mm的钢污染物。
We have designed and constructed a computer controlled food contaminant detection system for practical use, based on high-Tc SQUID detectors. The system, which features waterproof stainless steel construction, is acceptable under the HACCP (Hazard Analysis and Critical Control Point) programme guidelines. The outer dimensions of the system are 1500 mm length × 477 mm width × 1445 mm height, and it can accept objects up to 200 mm wide × 80 mm high. An automatic liquid nitrogen filling system was installed in the standard model. This system employed a double-layered permeable metallic shield with a thickness of 1 mm as a magnetically shielded box. The distribution of the magnetic field in the box was simulated by FEM; the gap between each shield layer was optimized before fabrication. A shielding factor of 732 in the Z-component was achieved. This value is high enough to safely operate the system in a non-laboratory environment, i.e., a factory. During testing, we successfully detected a steel contaminant as small as 0.3 mm in diameter at a distance of 75 mm.