ASTM International

Standard Test Method for Automatic Particle Counting of Lubricating and Hydraulic Fluids Using Dilution Techniques to Eliminate the Contribution of Water and Interfering Soft Particles by Light Extinction
 N D7647

Annotation

This test method covers the determination of particle concentration and particle size distribution in new and inservice oils used for lubrication and hydraulic purposes.

Particles considered are in the range from 4 m (c) to 200 m (c) with the upper limit being dependent on the specific automatic particle counter being used.

NOTE 1—For the purpose of this test method, water droplets not masked by the diluent procedure are detected as particles, and agglomerated particles are detected and reported as a single larger particle.

NOTE 2—The subscript (c) is used to denote that the apparatus has been calibrated in accordance with ISO 11171. This subscript (c) strictly only applies to particles up to 50 m.

Lubricants that can be analyzed by this test method are categorized as petroleum products or synthetic based products, such as: polyalpha olefin, polyalkylene glycol, or phosphate ester. Applicable viscosity range is up to 1000 mm2/s @ 40°C. This procedure may be appropriate for other petroleum and synthetic based lubricants not included in the precision statement.

Samples containing visible particles may not be suitable for analysis using this test method.

Samples that are opaque after dilution are not suitable for analysis using this test method.

The test method is specific to automatic particle counters that use the light extinction principle and are calibrated according to the latest revision of ISO 11171.