A non-destructive inspection or testing (NDT/NDI) device configured for inspecting a test object, comprising: a probe (106 or 107) configured for pulsing a test object during a testing cycle at a testing location with N ultrasonic pulses to produce and receive N sets of wave responses, and to produce therefrom N sets of electric echo signals; at least one analog to digital converter configured to digitize the N sets of echo signals and to produce therefrom N sets of digitized signal samples, which correspond respectively to N sets of acquired signal samples and N sets of noise signal samples; a digital logic device , having a data processing unit configured to execute an averaging process by which the N sets of signal samples are summed and averaged to produce a final testing result; wherein each one of the N sets of noise signal samples includes a residual acoustic energy from a previous one of the N sets of noise signal samples; wherein the digital logic device further comprises a pulser control unit configured to control the pulsing according to a dithery pulsing sequence by which the probe is pulsed in a random dithery manner given by a plurality of dither values which are random numbers between one pulse and another so that the residual acoustic energies from the N sets of the noise signal samples are decorrelated from each other to transform the residual acoustic energies into white noise; and, wherein the dithery pulsing sequence is governed by T 0 +nT+D n , wherein n=1 to N, with n to be a sequence number at which the probe is pulsed, T 0 to be a starting time of the pulsing, T to be a pulse time interval, and D n are dither values as periods of time. a probe (106 or 107) configured for pulsing a test object during a testing cycle at a testing location with N ultrasonic pulses to produce and receive N sets of wave responses, and to produce therefrom N sets of electric echo signals; at least one analog to digital converter configured to digitize the N sets of echo signals and to produce therefrom N sets of digitized signal samples, which correspond respectively to N sets of acquired signal samples and N sets of noise signal samples; a digital logic device , having a data processing unit configured to execute an averaging process by which the N sets of signal samples are summed and averaged to produce a final testing result; wherein each one of the N sets of noise signal samples includes a residual acoustic energy from a previous one of the N sets of noise signal samples; wherein the digital logic device further comprises a pulser control unit configured to control the pulsing according to a dithery pulsing sequence by which the probe is pulsed in a random dithery manner given by a plurality of dither values which are random numbers between one pulse and another so that the residual acoustic energies from the N sets of the noise signal samples are decorrelated from each other to transform the residual acoustic energies into white noise; and, wherein the dithery pulsing sequence is governed by T 0 +nT+D n , wherein n=1 to N, with n to be a sequence number at which the probe is pulsed, T 0 to be a starting time of the pulsing, T to be a pulse time interval, and D n are dither values as periods of time. <EOS>