Study on location of analog source of optical fiber acoustic emission

摘要

The sensor array is structured by the ring optical fiber Sagnac interferometers by way of point sensors to detect and locate the analog source of the acoustic emission (AE). The principle of the ring optical fiber Sagnac interferometer is used to detect ultrasonic waves and locate the AE source is given. One method based on microcomputer intelligent detection is proposed. A steel plate is used as the medium of the acoustic wave propagation, and four sensors are respectively placed on the steel plate to structure a sensor array with point sensors. The home-made analog source of the acoustic emission is applied to do the experiment. When the ultrasonic signal is generated by driving the analog source of the acoustic emission at any position of the steel plate, the ultrasonic signal will be received by the four sensors at the different time. The microcomputer will count the position of the AE source with the time differences of the four received signals and set value of the velocity at which the ultrasonic waves propagating in a solid plate, and then the coordinates of the AE source are displayed by LED.