ASTM D4898 Test Method for Insoluble Contamination of Hydraulic Fluids by Gravimetric Analysis
3. Summary of Test Method
3.1 The insoluble contamination is determined by passing a given quantity ofa fluid sample through a membrane filter disk and measuring the resultant increase in the mass of the filter. The fluid sample is drawn through the filter by a vacuum and the insoluble contamination is collected on the surface of the filter. In addition, the filter disk is microscopically scanned for excessively large particles, fibers, or other unusual conditions.
4. Significance and Use
4.1 This test method indicates and measures the amount of insoluble contamination of hydraulic fluids. Minimizing the levels of insoluble contamination of hydraulic fluids is essential for the satisfactory performance and long life of the equipment. Insoluble contamination can not only plug filters but can damage functional system components resulting in wear and eventual system failure.
