Session: Research Posters

Paper Number: 119965

119965 - Thermography With an Ultrasonic Transducer and Buffer Rod 

Temperature plays a crucial role in various aspects of technology, mass production, and all forms of life and hence needs to be controlled. Thermometry/thermography is becoming increasingly important every day and is necessary to control the temperature. In this study, a new thermometry and thermography technique was investigated by using three different temperature measurement techniques. The first method was acoustic measurement using an ultrasonic transducer. The second method was an infrared contactless thermal camera to measure temperature. And finally, thermocouples are used as they are the most used temperature measurement method due to their low cost and simplicity. Ultrasonic transducers are essential for the measurement of corrosion in pipes and cooling systems of nuclear power plants operating at elevated temperatures. This study aimed to perform thermometry and thermography with acoustic imaging technique using a high-frequency ultrasonic transducer with piezoelectric elements. To protect the acoustic transducers from higher temperatures, a cylindrical buffer rod made of 304L stainless steel has been used. As the temperature of the buffer rod increases, the speed of the acoustical wave speed in the buffer rod would decrease, resulting in a detectable change correlating the speed of sound to temperature. The experiments were conducted from room temperature to 540 ℃ in 50 ℃ increments from the ambient temperature with a plate-type heater setup. When the temperature distribution on the buffer rod used in this study is examined, it was observed that the surface contacted by the transducer remains almost at room temperature while the temperatures in the part of the bar that touches the plate-type heater have been as high as 540 ℃. As a secondary method, the temperature distribution on the buffer rod was also monitored with an off shelve infrared thermal camera. In addition, a finite element steady-state thermal analysis was performed by using the commercially available software ANSYS. The simulation model results have been compared with these infrared thermal camera images. A good match was observed between the thermal images and simulation results. In addition, thermocouples placed at two different points on the rod and the temperature measurement made with an infrared camera were compared, and a good match was observed. This study indicates that ultrasonic transducers with buffer rods can be used for thermometry and thermography in various application spaces. This expands the use of acoustics beyond its usual application for non-destructive testing and structural health monitoring.

Keywords: Acoustic, Ultrasonic Transducer, Thermometry, Thermography, Infrared Thermal Camera, Temperature Distribution 

Presenting Author: Mustafa Demirci University of South Florida

Presenting Author Biography: Dr. Guldiken is a Professor and Associate Dean for Academic Affairs of the College of Engineering at USF

Authors:

Mustafa Demirci University of South Florida
Rasim Guldiken University of South Florida