Dead zone inspection with ultrasonic testing using signal integration

A method of inspecting a structure, the method comprising:

• directing ultrasound waves into the structure from a front wall;
• receiving reflected waves to generate a response signal;
• rectifying the response signal to generate a rectified signal;
• integrating a portion of the rectified signal within a detection time window to determine an energy sum;
• and
• generating output based on the energy sum;
• wherein the detection time window is restricted to a front wall reflection and at least a portion of a near-surface dead zone following the front wall reflection.

A non-transitory computer readable medium embodying programmed instructions executed by a processor, wherein the instructions direct the processor to implement a method of inspecting a structure, the method comprising:

• directing ultrasound waves into the structure from a front wall;
• receiving reflected waves to generate a response signal;
• rectifying the response signal to generate a rectified signal;
• integrating a portion of the rectified signal within a detection time window to determine an energy sum;
• and
• generating output based on the energy sum;
• wherein the detection time window is restricted to a front wall reflection and at least a portion of a near-surface dead zone following the front wall reflection.