1.1 This specification covers the procedure and acceptance standards for straight-beam, pulse-echo, ultrasonic examination of rolled carbon and alloy steel plates, 3/8 in. [10 mm] in thickness and over This procedure covers the standard and acceptance standards for straight-beam, pulse-echo, ultrasonic examination of rolled carbon and alloy steel plates. The amplitude linearity of the apparatus to be used shall be checked by positioning the transduce