(under subclass 128) Subject matter including means blocking the normal light refraction from a fluid or a solid in a fluid, and passing the light bent due to localized changes in the refractive index of the fluid or the solid in a fluid; or including means causing a light pattern to vary as a result of the changes in the refractive index of the fluid or the solid in a fluid.
(1) Note. The localized changes in the refraction are caused by variations in the density of the fluid caused by the solids in the fluid, temperature changes in the fluid, or other forces which affect the fluid.
SEE OR SEARCH THIS CLASS, SUBCLASS:
344, for electrophoresis apparatus which detects a Schlieren pattern.
361+, for the combination of an interference system with a Schlieren arrangement where a refraction test is involved.
SEE OR SEARCH CLASS 73, Measuring and Testing,
147, for Schlieren apparatus combined with the testing of objects in wind tunnels.
