METHOD AND DEVICE FOR DETECTING PENETRATION CRACKING OF RUBBER LINING APPLIED TO, METAL SURFACE

摘要

PROBLEM TO BE SOLVED: To detect a crack in a rubber lining applied to a metal surface whether or not it is penetrated up to the surface of a metal. ;SOLUTION: An electrolytic solution 7 of a sodium compound is applied to the surface of a rubber lining 5 of a rubber lining roll so as to be permeated into a crack 9. The positive electrode of a constant-current DC voltage generator 1 is connected to an iron core 6 with an earth terminal 3, and the negative electrode thereof is connected to a detecting probe 2, and the probe 2 is placed on the opening of the surface of the crack 9 to apply the voltage 24V of the DC voltage generator. If the crack is penetrated up to the core 6, a current flows through the electrolytic solution 7, and the electrolytic solution 7 is electrolysed to become gaseous bubbles 4, and are jetted from the opening of the crack 9. The color of the bubbles 4 is white and is easily discriminated from the rubber lining 5. Meanwhile, if the crack is not penetrated, the reaction duet to electrolysis is not caused, so that bubbles are not jetted.;COPYRIGHT: (C)1999,JPO