A method for performing metrology qualification of a non-destructive inspection, NDI, ultrasonic system and/or an NDI ultrasonic transducer, comprising: performing, by the NDI ultrasonic system, an ultrasonic scanning operation on a calibration coupon, the ultrasonic scanning operation generating a scan signal; the calibration coupon including one or more portions without any defects and one or more portions with a the defect; superimposing a time-domain qualification mask on the scan signal, the time-domain qualification mask created using at least one of a specification for a workpiece and process specification requirements for processing the workpiece, evaluating the scan signal using the time-domain qualification mask; validating a porosity sensitivity of the NDI ultrasonic system and/or the NDI ultrasonic transducer using a frequency-domain qualification mask; and qualifying the NDI ultrasonic system and/or the NDI ultrasonic transducer in response to the scan signal being below the time-domain qualification mask for a portion of the calibration coupon without the defect and the scan signal being above the time-domain qualification mask for another portion of the calibration coupon comprising the defect, and the porosity sensitivity of the NDI ultrasonic system being validated; wherein the method further comprises creating the frequency-domain qualification mask for a particular workpiece by generating an ultrasonic signal by performing an ultrasonic scanning operation on a metrology coupon that satisfies the specification for the workpiece; converting the ultrasonic signal from a time domain signal to a frequency domain signal (232, 402); and applying a bandwidth mask that covers the frequency domain signal (232, 402); the method further comprising calibrating at least one of the NDI ultrasonic system or the NDI ultrasonic transducer until the porosity sensitivity of the NDI ultrasonic system is validated. performing, by the NDI ultrasonic system, an ultrasonic scanning operation on a calibration coupon, the ultrasonic scanning operation generating a scan signal; the calibration coupon including one or more portions without any defects and one or more portions with a the defect; superimposing a time-domain qualification mask on the scan signal, the time-domain qualification mask created using at least one of a specification for a workpiece and process specification requirements for processing the workpiece, evaluating the scan signal using the time-domain qualification mask; validating a porosity sensitivity of the NDI ultrasonic system and/or the NDI ultrasonic transducer using a frequency-domain qualification mask; and qualifying the NDI ultrasonic system and/or the NDI ultrasonic transducer in response to the scan signal being below the time-domain qualification mask for a portion of the calibration coupon without the defect and the scan signal being above the time-domain qualification mask for another portion of the calibration coupon comprising the defect, and the porosity sensitivity of the NDI ultrasonic system being validated; wherein the method further comprises creating the frequency-domain qualification mask for a particular workpiece by generating an ultrasonic signal by performing an ultrasonic scanning operation on a metrology coupon that satisfies the specification for the workpiece; converting the ultrasonic signal from a time domain signal to a frequency domain signal (232, 402); and applying a bandwidth mask that covers the frequency domain signal (232, 402); the method further comprising generating an ultrasonic signal by performing an ultrasonic scanning operation on a metrology coupon that satisfies the specification for the workpiece; converting the ultrasonic signal from a time domain signal to a frequency domain signal (232, 402); and applying a bandwidth mask that covers the frequency domain signal (232, 402); the method further comprising calibrating at least one of the NDI ultrasonic system or the NDI ultrasonic transducer until the porosity sensitivity of the NDI ultrasonic system is validated.