12.1.6.An ultrasonic pulse echo instrument with a range greater than the web thickness
of the rail shall be used. The test shall be carried out over the web anywhere
along the first meter of the top end of every rail at any other places selected by
the Inspector. The defective portion of rails with piping will be rejected. In the
event of dispute, a macro graphic test of a test piece from the top end of the rail
shall be carried out.