Non-Intrusive and Quick Response Thermometry Using Laser-Induced Thermal Acoustics (LITA)

Toshiharu MIZUKAKI
2007 Journal of Fluid Science and Technology  
By using laser-induced thermal acoustics, we demonstrate a non-invasive and remote method to measure the speed of sound and temperature ranging from 278 K to 341 K in distilled water at atmospheric pressure. The accuracies of the measured speed of sound and temperature were found to be 3% and 4%, respectively. Single-shot precisions based on three standard deviations of 20 samples were within 4% for the speed of sound and the temperature. The time resolution for each measurement was 300 ns.
more » ... r-induced thermal acoustics (LITA) Laser-induced thermal acoustics (LITA) is a type of ultrasonic effect generated by the compulsion in a medium due to the crossing of laser beams. The ultrasonic effect is derived from the dynamic gratings (DG) (5) induced by the interference of the crossing laser beam. Cummings (6) -(8) reported the fundamental characteristics of LITA. Danehy (9) and Hart et al. (10) -(12) developed the thermometry and velocimetry for air by using the LITA theory.
doi:10.1299/jfst.2.282 fatcat:6bqe2jyk6rfufoslgrzz4psaue