Patent ID: 8171796

Claim:
An acoustic emission detector comprising: an acoustic emission sensor configured to detect an acoustic emission; a destruction judging section that judges that a material is subject to destruction when a predetermined number or more of points defined by at least two parameters calculated based on a signal from the acoustic emission sensor are located within a predetermined region of a parameter space in the parameter space defined by at least two parameters that are configured to be generated based on the signal from the acoustic emission sensor; a calculating section that calculates a plurality of parameters based on the signal outputted from the acoustic emission sensor; and a correlation parameter determining section that determines mutually correlated parameters among the plurality of parameters and that determines parameter combinations of which absolute values of correlation coefficients are not smaller than a predetermined value and which have a strong tendency of linearity, wherein the destruction judging section judges that the material is subject to destruction when a predetermined number or more of points defined by mutually correlated parameters calculated based on the signal from the acoustic emission sensor are located within a predetermined region of the parameter space defined by the mutually correlated parameters in the parameter space defined by the mutually correlated parameters determined by the correlation parameter determining section.