Non-destructive testing equipment employing SQUID-type magnetic sensor in magnetic shield container

摘要

A non-destructive testing equipment comprises a magnetic sensor located within a magnetic shield container. The magnetic sensor includes a SQUID that is a magnetic sensor having a very high sensitivity. A magnetically uniform inspection zone is formed in the magnetic shield container. While a rod-like material to be tested passes through the inspection zone at a uniform velocity, the magnetic sensor can detect an appreciable magnetic field variation that is caused by impurities or minor defects contained in the object to be tested.