Re: Flaw Detector Signal Processing Most UT systems have 3 options for display:
RF, rectified, and envelope.
The envelope is obtained by using in-phase/quadrature techniques which can be implemented on a processor by the use of a Hilbert transform.
Additional display processing is common in newer systems, where the X scale is labled according to your calibration, and the DAC curve is also recorded electronically and possibly displayed during the inspection.
The use of gates usually simply specifes start and end depths, and an amplitude (screen height) which is not related to the DAC curve (the gate has constant height). Recorded points are sometimes limited to a few of the peaks within the gate instead of the complete signal. A peak detect algorithm is therefore usually used (this is more efective on the envelope signal or else you will get multiple peaks per indication).
As you can see there is a whole host of issues that can be incorporated into the display/ recording of UT signals, and this is constantly evolving. These differences/varieties are what makes the choice of UT equipment all the more complex.
: : Receive a cordial greeting.
: : What kind of signal processing is usually carried out in the commercial flaw detectors?
: : I need to write a program that takes the RF ultrasound data, process it and display it like do the commercial flaw detectors (like Krautkramer USM22). Additionally I have to add gates to my programs and the possibility of executes automatic measurements.
: : I someone could give some hints on what I have to do or how to start, I would be really grateful.
: The USM22 is very limited to what report / documentation that can be printed.
: You will require software such as UltraDoc for this purpose
: : For your help, thank very much