Sizing indications with ultrasonics can be challenging. For large indications sizing by probe travel is appropriate, for indications smaller than the beam width amplitude-based sizing. But what about indications smaller than the wavelength? This video is all about those TINY defects and why you should NEVER use Flat Bottom Holes smaller than ¼ of the wavelength!
► Video: Sizing of Small Defects with Ultrasonic Testing: Don't use Flat Bottom Holes!!!
https://youtu.be/mr778r1uStw
► Paper: Correct sizing of reflectors smaller than one wavelength
https://www.researchgate.net/publication/325597212
► Video: Ultrasonic Testing Sizing Method Comparison & Limitations
https://youtu.be/zZroaqqDGug
► Video: Basics of Ultrasonic Testing and Sizing
https://youtu.be/5Pg21GHtKO8
► Video: Ultrasonic Calibration and Sizing with DGS (AVG)
https://youtu.be/OeDGVhwU5lE