Millipore Filter Technique for Analysis of Contamination in Missile Hydraulic Fluid

摘要

The servo valves found in the guidance system of missiles are extremely sensitive to solid particle contamination ex¬tending to particles of microscopic size.nForty-one samples of missile hydraulic fluids including new, used, and reprocessed oils, were filtered through a millipore filter. Four areas of the millipore filter were photographed at 100X. The size range and distribution of the solid particles were established for the areas photographed. Total counts for the entire filtering area were then calcu-lated.nThe millipore filter technique provides a fairly re¬liable estimate of the level of contamination of a missile fluid, however, the validity of the results is dependent upon the control of the many variables encountered.