光音響信号と反射光信号の同時測定による 内部欠陥検出に関する研究

Abstract

Using a photoacoustic effect，a nor-destructive and non-contact detection has been studied. In an earlier study，it has been seen that the sensitivity of the internal defective detection fall off due to surface condition. In order to improve the sensitivity，it was tried to compensate photoacoustic signal using reflected light. After relation between photoacoustic and reflected light signals was researched，an equation for compensation was led. To get total amount of reflected light in the equation,an angular distribution of reflected light was examined，and the number of photo diode necessary to compensate the photoacoustic signal was determined. Simultaneously measuring photoacoustic and reflected light signals，i nternal defect of aluminum sample was measured. As a result of compensation，it is possible to improve the sensitivity of internal defective detection.