Flaw detection, characterization and study

Apparatus for detecting, characterizing and studying flaws in work by acoustical echo processing, said apparatus including first means for propagating acoustic energy on said work to produce a first echo from flaws in said work, and said first propagating means including first focusing means for focusing said first acoustic energy, second means for propagating second acoustic energy on said work to produce a second echo from flaws in said work, said second propagating means including second focusing means for focusing said acoustic energy, means, common to said first and second propagating means, for causing said first and second acoustic energy to scan said work, third means, connected to said scanning means and to said first and second propagating means, for producing a first echo indication only from the acoustic energy propagated by said first propagating means during a first part of each cycle of said scanning, and fourth means, connected to said scanning means and to said first and second propagating means, for producing only a second echo indication separate from said first echo indication during another part of each scanning cycle from the acoustic energy propagated by said second propagating means, said first focusing means being adapted to focus the first acoustic energy at a point on a plane at or near the work, said plane being generally perpendicular to the direction of propagation of the wave front of said first acoustic energy, and said second focusing means being adapted to focus the second acoustic energy, at each point along a line along the direction of the propagation of the wave front of said second acoustic energy.