In the case of multi-sensor array detection

the ultrasonic wave emitted by each array is the same

which makes it impossible for the receiving sensing array to distinguish the transmitting source effectively and restricts the accurate solution of the space sound field of the specimens. For this reason

binary FM coded signals are adopted to excite each sensor array

and to identity identification information of signal source by using pulse discrimination circuit at the receiving end

which can be used to effectively distinguish the transmitting source in the multi-sensor array structure. The method is applied in pipeline defect detection experiment

and the experimental results show that the signal source identification rate is 94. 8 % from the binary coded ultrasonic signal

which not only realizes the accurate discrimination of the echo information of each array element in the sensor array structure

but also coded ultrasonic signals can be used to improve the average transmitting power and echo signal-to-noise ratio of the detected signal.