NBN EN 12680-3:2012

This European Standard specifies the requirements for the ultrasonic testing of spheroidal graphite cast iron castings and the methods for determining internal discontinuities by the pulse-echo technique.
This European Standard does not apply to ultrasonic testing of the nodularity of spheroidal graphite cast irons.
This European Standard does not apply to transmission technique.
NOTE The transmission technique has insufficient sensitivity to detect the discontinuities found in spheroidal graphite cast iron castings and is used in exceptional cases only.