Traditional techniques cannot be used to measure the fluid flow in micro-test sections and fibrous assemblies. A new optical instrument, the modified laser Doppler ane mometer ( MLDA ), was developed to measure velocities in micro-test sections with a spatial resolution of 10 microns. The ability of this instrument to measure velocity fields was established by experiments in a 400 micron capillary tube, a 300 micron slot, and more complicated micro-test geometries. The MLDA is an accurate tool for measuring point velocities in micro-test sections and can be used to study the laminar, viscous flow of fluids in such sections in a manner never before possible.
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