Holographic interferometry as a tool for visualization of temperature fields in fluids

Measurement of temperature field in moving fluids is connected with many difficulties. Usage of point temperature measurement methods, such as Constant Current Anemometry (CCA), is limited to frequencies up to 3kHz. This frequency should be the limiting factor for using the CCA in fluid when fast change of temperature occurs. This shortcoming of CCA measurements should be overcome by using of optical methods such as digital holographic interferometry. It is necessary to employ a special holographic setup with double sensitivity instead of the commonly used Mach-Zehnder type of holographic interferometer in order to attain the parameters sufficient for the studied case. This setup is not light efficient like the Mach-Zehnder type but has double sensitivity. The special technique of acquiring and phase averaging of results from holographic interferometry is presented