Abstract
With an acoustic emission technique, the method for stress corrosion crack detection has been studied. However, piezoelectric type AE sensor which is generally employed in AE measurement is not allowed to use in corrosive liquid because it has electronic components in it. On the other hand, an optical fiber sensor can be immersed into liquid because the fiber is made of SiO_2 and have no electronic circuit in a sensor portion. In this study, an immersion type optical fiber AE sensor with a parabolic reflector was developed. The parabolic reflector enables to improve its sensitivity and directivity of ± 11 degree in full width half maximum. The sensor is able to detect liquid-borne AE from stress corrosion cracks in sensitized SUS 304 steel.
