A method for detecting hermetic defects in high temperature superconducting tapes and wires using visible changes in colour

摘要

A method for detecting hermetic defects in a high temperature superconductor (HTSC) which comprises an HTSC core and an outer layer is disclosed, wherein the method includes causing a tracer gas or liquid such as ammonia, H2O, halogen or an alcohol to penetrate the HTSC core of the conductor and subsequently exposing the conductor either to an indicating chemical such as indophenol blue which undergoes a visible change in colour on contact with the tracer gas or liquid at hermetic defects in the outer layer of the conductor to expose the hermetic defects, or to an environment which will cause any tracer gas or liquid contacting the environment at hermetic defects in the outer layer of the conductor to undergo a visible change to expose the hermetic defects