Acoustic emission method for detection and monitoring of corrosion

Claim 1

A non-destructive chemical-reaction testing method utilizing an electroacoustic sensing and recording device of the type comprising an acoustic transducer for picking up acoustic emissions, a signal processor responsive to the output of the transducer for providing discrete output pulses corresponding to each of the acoustical emissions picked up by the transducer, and a counter for accumulating, and providing an indication of, the discrete pulses from the processor, comprising the steps of: acoustically coupling said transducer to a first specimen which is subject to and undergoing a continuous progressing chemical reaction of interest having known chemical process parameters for picking up acoustical emissions therefrom; making a first fixed-interval recording of the pulses accumulated by said counter in response to said progressing chemical reaction as a function of a single given continuous physical parameter, and thereby establish a standardized acoustic signature corresponding to said first specimen; acoustically coupling said transducer to a second specimen which is to be tested for the purpose of measuring any progressing chemical reaction extant therein; making a second fixed-interval recording of all pulses accumulated by said counter as a result of subjecting said second specimen to a like degree of said single given continuous physical parameter and for a like interval; and comparing said first and second recordings to obtain a degree of correlation therebetween, the existence of a positive correlation being indicative of the existence of the chemical reaction of interest in said second specimen, and the existence of a negative correlation indicating an absence of said chemical reaction of interest.