4. Defect mapping acquisition

Fault mapping is acquired by signal processing using measurement gates.

The gates measure the transmitted or reflected A-SCAN signal to automatically associate two digital values with each point: a time and an amplitude.

The amplitude measured is either that of the largest signal peak in the gate, or that of the first peak in the gate.

The time measured is the time between ultrasound emission and the appearance of the largest signal peak in the gate, or that of the first peak in the gate (figure 9 ).