Fast method for visualization of temperature distribution using acoustic computerized tomography

Sound velocity is dependent on medium temperature and is estimated from the time of flight of sound. We propose a fast method for the visualization of temperature distribution using acoustic computerized tomography (A-CT). In this study, considering the property of a temperature gradient field, whic h is the visualization object and is approximated by a Gaussian function, t he number of data points required by the CT is optimized and the speed of v isualization is improved. As a result of noncontact measurements of the tem perature distribution in the circular space of 100 mm radius which includes a high-temperature area of about 40 mm radius, sufficient spatial resoluti on is obtained by the data acquisition system which combines linear scannin g of 11 measurement points and rotational scanning with a 22.5 degrees angu lar step. In addition to the optimization of the data acquisition geometry, an aerial delay-line oscillator is used for the detection of sound velocit y, in order to sensitize and simplify the system. Visualized results obtain ed by the A-CT agree well with the measurements taken by thermocouples. The fast visualization scheme proposed in this paper has an advantage over con ventional methods in such applications as air conditioning, reactor monitor ing and atmospheric monitoring among others.