High temperature ultrasonic testing

Many methods and applications of ultrasonic examination at high temperature are described. Problems involved in high temperature inspection are considered in order to choose a proper probe design to be employed in molten metal. The role of velocity of sound measurements in elementary liquid theory is also described. The sound velocities in liquid paraffin, turpentine, water, lead, and lead-indium alloy (10% indium) are measured at various temperature using pulse-echo method. The values obtained are within the range of tabulated value. At temperature 350 °C, the velocity of sound in molten lead is 1801 ± 29 m/s, while in molten lead-indium alloy (10% indium) is 1886 ± 32 m/s. Suggestions are offered for improvements and wider use.