METHOD FOR MEASUREMENT AND EVALUATION OF STRESS ENLARGEMENT FACTOR OF CRACK BY AC POTENTIAL DIFFERENCE METHOD AND APPARATUS THEREFOR

摘要

PROBLEM TO BE SOLVED: To measure more simply with a higher sensitivity a stress enlargement factor for evaluating soundness of equipment and structures such as pressure vessels, pipings, etc., of nuclear power plants, thermal power plants, chemical plants, oil plants, etc. ;SOLUTION: A potential difference-measuring wire constituting a potential difference-measuring terminal 5 is wound as a coil 8. A change of a potential difference due to a change of an induced electromotive force which increases a magnetic flux in a space of potential difference-measuring terminals 5 resulting from a change of a current is added to a change of a potential difference due to a change of an electromagnetic physical property value of an object 3 to be measured because of a change of a stress (or force). A measured a.c. potential difference due to a change of a stress enlargement factor is increased, thereby improving measurement sensitivity.;COPYRIGHT: (C)1997,JPO