Krautkramer is the world's largest manufacturer and
supplier of ultrasonic materials testing equipment. Our
products are used mainly to test materials such as
steel or plastic for cracks and defects, and to
measure material thickness either as part of a
manufacturing cycle or during the life of a product or
component.
Also, see our ultrasonic reference data section with Velocity and Acoustic Impedance Table, Decibel vs. Amplitude Ratio Chart, Near Field Length, and Useful Formulas at
http://www.krautkramer.com/reference/intro.htm.