Esterer Gießerei - Ultra-sonic testing

Ultra-sonic testing, in short UT-testing according to EN 12680-1,-2,-3, is a non-interfering control method where via ultrasound imperfections in materials can be found. The procedure is suitable for all sound conductive materials and thus for metals. It investigates internal and external imperfections and it measures layer thickness.

The physical basis for ultrasonic testing is the varied propagation of sound waves according to its medium. On the transfer from one to another material the changed wave impedance leads to the fact that sound waves are spreading at a different speed, or they change directions or they are partially reflected. The reflected share of the waves is the greater the higher the difference between the wave impedance between the two materials is.

Such a border surface where the audio impulse is reflected can be a crack or cavity in a material. Through special measuring methods after a transmission of an impulse a signal image is created which enables to define the position and the size of the imperfection within the material.

In general we divide between two measuring processes: reflective wave procedure, also impulse-echo procedure and the through-sonic procedure.