High-Tc SQUID Metal Detection System for Food and Pharmaceutical Contaminants

Saburo TANAKA
Shozen KUDO
Yoshimi HATSUKADE
Tatsuoki NAGAISHI
Kazuaki NISHI
Hajime OTA
Shuichi SUZUKI

Publication
IEICE TRANSACTIONS on Electronics   Vol.E88-C    No.2    pp.175-179
Publication Date: 2005/02/01
Online ISSN: 
DOI: 10.1093/ietele/e88-c.2.175
Print ISSN: 0916-8516
Type of Manuscript: Special Section INVITED PAPER (Special Section on Superconducting Electronic Devices and Their Applications)
Category: 
Keyword: 
SQUID,  superconductor,  food safety,  detection,  inspection,  contaminant,  

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Summary: 
There is a possibility that individuals ingest contaminants that have been accidentally mixed with food because processed foods have become very common. Therefore a detection method of small contaminants in food and pharmaceuticals is required. High-Tc SQUID detection systems for metallic contaminants in foods and drugs have been developed for safety purposes. We developed two systems; one large system is for meat blocks and the other small system is for powdered drugs or packaged foods. Both systems consist of SQUID magnetometers, a permanent magnet for magnetization and a belt conveyor. All samples were magnetized before measurements and detected by high Tc SQUIDs. As a result, we successfully detected small syringe needles with a length of 2 mm in a meat block and a stainless steel ball as small as 0.3 mm in diameter.