Angle beam calibration requires use of an appropriate test block that provides two sound paths of known length. Commonly this will be an ASTM E-164 or IIW-type block, although other standards like AWS DSC blocks can also be used. The general procedure description below assumes use of an IIW Type 1 calibration block or equivalent.
As with any other transducer calibration, this should be performed using a block made of the same material as the test piece. Angle beam calibration blocks are commercially available in a variety of steel alloys as well as aluminum and titanium.