Development of an Ultrasonic Thermometry System

The purpose of this study was to develop and apply a custom computational algorithm to estimate internal temperature distribution of heated materials by ultrasound. The experimental setup was carry-out using an ultrasonic pulser- receiver system to drive a longitudinal ultrasonic transducer of 5.0 MHz. A general-purpose oscilloscope was used as data acquisition system and ultrasonic signals waveform viewer. Measurements were performed during the heating and cooling regime of a structural aluminum block with the time-base of the oscilloscope set to 2.5 ns. A thermocouple temperature measurement system was used to verify and validate the temperature distribution found for ultrasonic thermometry method. The developed computational algorithm was responsible to communicate with oscilloscope device and evaluate the temperature of the block in real-time. The comparison of the temperature measurements derived from the ultrasonic thermometry with thermocouple temperature system showed an excellent accuracy raging from 97% to 99% for heating regime and cooling, respectivally. The presented methodology showed to be relevant to estimate internal temperature of the heated metal. Accurate data measurements were provided by oscilloscope, compared to those found using thermocouple instrumentation.