Most modern ultrasonic flaw detectors incorporate digital rather than analog signal processing. While some older analog instruments are still in use, microprocessor-based digital processing is now the industry standard for portable flaw detectors. Its major advantages include:
Precision and repeatability of test setups, which can be stored for quick recall
Stability of horizontal and vertical linearity (no drift with time or temperature)
Digital precision in measurement of amplitude and depth/distance, including trigonometric calculations in angle beam testing
Digital filtering can improve near surface resolution and signal-to-noise in high gain applications
Waveform freeze, peak memory, and zoom functions for easier analysis
Fast and reliable implementation of sizing techniques such as DAC, TVG, and DGS
Datalogger software for storage of screen displays and measurements in internal memory or on removable storage cards
USB interface for offloading test data to computers for storage and further analysis
The potential advantage of analog processing in some cases is faster screen refresh and/or data acquisition rates.