Laser schlieren deflectometry (nonfiction)
Laser schlieren deflectometry (LSD) is a method for a high-speed measurement of the gas temperature in microscopic dimensions, in particular for temperature peaks under dynamic conditions at atmospheric pressure.
The principle of LSD is derived from schlieren photography: a narrow laser beam is used to scan an area in a gas where changes in properties are associated with characteristic changes of refractive index. Laser schlieren deflectometry is claimed to overcome limitations of other methods regarding temporal and spatial resolution.
The theory of the method is analogous to the scattering experiment of Ernest Rutherford from 1911. However, instead of alpha particles scattered by gold atoms, here an optical ray is deflected by hot spots with unknown temperature.
- Laser schlieren deflectometry @ Wikipedia