Non-destructive testing equipment having SQUID type magnetic sensor

摘要

A non-destructive testing equipment comprises a magnetic field generator for generating a uniform magnetic field, and a magnetic sensor accommodated in a thermal insulation container and filled with a liquid nitrogen. The thermal insulation container is located within a magnetic shield container having an opening. The magnetic sensor includes a SQUID that is a magnetic sensor having very high sensitivity. The magnetic sensor can detect, through the opening, an appreciable variation of the magnetic field that is caused by small impurities or minor defects contained in the object to be tested.