FIBER OPTIC SENSING ON AND WITHIN MATERIALS

APPROXIMATELY 210 BILLION DOLLARS WAS SPENT IN 1992 ON CORROSION IN THE UNITED STATES. ACCORDING TO THE NATIONAL ASSOCIATION OF CORROSION ENGINEERS, THIS IS ROUGHLY FOUR PERCENT OF THE GNP. MANY METHODS OF DETECTION HAVE BEEN DEVISED WITH SOME SUCCESS. HOWEVER, AS THE NUMBERS REVEAL, THE PROBLEM OF CORROSION IS FAR GREATER THAN THE SOLUTIONS DEVISED. THE CORROSION OF METALLIC STRUCTURAL MEMBERS OFTEN SEVERELY DAMAGES OR COMPROMISES THE ASSOCIATED STRUCTURAL SYSTEM. IF THE CORROSION IS DETECTED AT AN EARLY STAGE, REMEDIAL COST-EFFECTIVE PREVENTIVE ACTIONS CAN BE UNDERTAKEN. THE METHODS THAT RESEARCHERS ARE INVESTIGATING WILL HELP TO SOLVE SOME OF THE PROBLEMS THAT CORROSION PRESENTS BY EARLY DETECTION AND REMEDIATION. IF A SAVINGS OF 0.1 PERCENT WERE REALIZED THIS WOULD REPRESENT A SAVINGS OF 210,000,000 DOLLARS IN THE UNITED STATES ALONE. THE DEVELOPMENT OF A SIMPLE, COST-EFFECTIVE MEANS OF DETECTING CERTAIN TYPES OF CORROSION EMPLOYING FIBER OPTICS IS BEING EXAMINED. THE MEANS BY WHICH THE DETECTION IS DONE CONSIST OF FIRST, A SIMPLE PEAK COLOR SHIFT CORROSION DETECTOR AND SECOND, A SOL-GEL EVANESCENT WAVE SENSOR.