Method for evaluation of acoustic anisotropy and measuring apparatus therefor

An apparatus for evaluating acoustic anisotropy in a material having a primary rolling direction, said apparatus comprising:

• (a) a first pulse generating and detecting means comprising a traverse beam probe having a double-structure vibrating element of transmitting ultrasonic pulses in two mutually perpendicular directions into said material, one said direction being parallel to said primary rolling direction and the other said direction being perpendicular to said primary rolling direction, and means for simultaneously detecting ultrasonic pulses reflected back from both of said directions;
• (b) a second-pulse generating and detecting means comprising an angle probe for transmitting ultrasonic pulses into said material in a direction at an angle to a thickness direction of said material and detecting reflected ultrasonic pulses;
• (c) a computing means comprising:
• a first acoustic anisotropy determining part for calculating speeds at which ultrasonic pulses propagate in each of said mutually perpendicular directions within said material and comparing said speeds to determine the presence of acoustic anisotropy in said material,
• a second acoustic anisotropy determining part for calculating refracting angles for ultrasonic pulses transmitted by said second pulse generating and detecting means in each of said mutually perpendicular directions and comparing said angles to determine the presence of acoustic anisotropy in said material, and
• means for calculating a deviation between a retracting angle, calculated as aforesaid, and an a experimentally determined retracting angle stored as a function of acoustic speed;
• (d) means for selecting one of said acoustic anisotropy determining parts for use in determining the presence of acoustic anisotropy in said material;
• and
• (e) a display means for displaying results of an acoustic anisotropy determination, propagation speed ratios, refracting angles, and aforesaid deviation.