Detection and measurement of defect size and shape using ultrasonic fourier-transformed waveforms

A method comprising:

• with one or more processors, receiving from an ultrasonic waveform detector ultrasonic waveform data representative of an ultrasonic waveform that propagated through a sample and resonated within a defect within the sample;
• with the one or more processors, selecting a portion of the ultrasonic waveform data;
• with the one or more processors, applying a Fast Fourier Transform to the portion of the ultrasonic waveform data to transform the portion from a time domain to a frequency domain;
• with the one or more processors, identifying a characteristic frequency of the portion in the frequency domain;
• and
• with the one or more processors, determining a characteristic of the defect by at least one of (1) comparing the characteristic frequency to a calibration curve or (2) calculating an approximate size of the defect using at least one equation that relates the characteristic frequency to the approximate size of the defect.

A non-transitory computer readable medium comprising instructions that cause a programmable processor to:

• receive from an ultrasonic waveform detector ultrasonic waveform data representative of an ultrasonic waveform that propagated through a sample and resonated within a defect within the sample;
• select a portion of the ultrasonic waveform data;
• apply a Fast Fourier Transform to the portion of the ultrasonic waveform data to transform the portion from a time domain to a frequency domain;
• identify a characteristic frequency of the portion in the frequency domain;
• and
• determine a characteristic of the defect by at least one of (1) comparing the characteristic frequency to a calibration curve or (2) calculating an approximate size of the defect using at least one equation that relates the characteristic frequency to the approximate size of the defect.