Practical Scanning SQUID System for Nondestructive Evaluation

Abstract

An advanced scanning Superconducting Quantum Interference Device (SQUID) system called a "Traveling SQUID-NDE" was developed for nondestructive evaluation (NDE). The traveling SQUID-NDE can continuously "travel" back and forth over the surface of an object during testing without the need for magnetic shielding. Such movement by the SQUID sensor itself enables the SQUID-NDE to scan objects of unlimited size. In this work, the traveling SQUID-NDE system was combined with a manipulator used by conventional robots (either rectangular-type or articulated-type) used in industry, to manipulate the SQUID sensor for travel across an object. The effectiveness of this robotic traveling SQUID-NDE system was demonstrated by using it to detect artificial damage in stainless steel samples. This robotic traveling SQUID-NDE system proved useful for measuring two-dimensional magnetic images of fixed objects.