In a basic ultrasonic test pattern (A scan) for contact testing, the initial pulse (assumeno sweep delay is used):

• A. Is the high indication on the extreme left side of the screen that represents the entry surface of the inspected part
• B. Is the first pulse that occurs near the right side of the screen and represents the opposite boundary of the inspected part
• C. Is an indication that appears and disappears during screening
• D. Is always the second pulse from the left on the viewing screen