A Compact EMAT Receiver for Ultrasonic Testing at Elevated Temperatures

For the past several years, the AISI and several national laboratories have cooperated on a program to develop ultrasonic transducers that can be used in steel mills at the highest temperatures encountered during the processing of the solid metal {1}. To date, pulsed laser light focused on the surface appears to make a satisfactory generator or transmitter for ultrasonic pulses while the EMAT or Electromagnetic Acoustic Transducer appears to hold the greatest promise for the receiver {2}. Both of these essentially noncontact devices can be made to withstand the very hot environmnent and they are not very sensitive to the quality of the surface