Cross-correlation analysis for temperature measurement

The current work demonstrates an optical technique that utilizes micron-resolution particle image velocimetry (µ-PIV) for temperature measurement. The technique is based on the premise that Brownian motion will cause width-wise broadening of the cross-correlation peak. A correlation-based PIV algorithm detects the magnitude of Brownian particle motion and can be used to determine the temperature of the fluid. Results were obtained using fluorescing (rhodamine 542/612) spherical 700 nm diameter polystyrene-latex particles in water. Temperature changes up to 25 °C were determined with an experimental accuracy of ±3 °C.