Patent ID: 8677826

Claim:
A method for evaluating received signals acquired during non-destructive ultrasonic testing of a test body, wherein ultrasound waves are generated inside the test body by an electromagnetic ultrasonic transducer functioning as an ultrasound transmitter and the ultrasound waves within the test body are detected as received signals by an electromagnetic ultrasonic transducer functioning as an ultrasound receiver and the received signals are evaluated to examine the test body, comprising: converting the ultrasound waves within the test body with electromagnetic ultrasonic transducer-receivers disposed spatially offset, with respect to each other by one-half of a wavelength of the ultrasound waves transmitted within the test body ultrasound transmitter, to obtain a first and a second data set of received signals; calculating phases φ1(t) and φ2(t), corresponding to the received signals of the first and second data sets; determining a phase difference φ(t)=φ1(t)−φ2(t); selecting received signals from the first and the second data sets of received signals, wherein the phase difference φ(t) is in a range between (180°−α−) and (180°+α+) with α− and α+<15°; and evaluating the selected received signals.