Browse Standards ARP4285
Current Reaffirmed 2008-06-04

Aerospace - Evaluation of Particulate Contamination in Hydraulic Fluid - Membrane Procedure ARP4285

This SAE Aerospace Recommended Practice (ARP) establishes a method for evaluating the particulate matter extracted from theh working fluid of a hydraulic system or component using a membrane. The amount of particulate matter deposited on the membrane due to filtering a given quantity of fluid is visually compared against a standard membrane in order to provide an indication of the cleanliness level of the fluid. A particular feature of this method is the membrane preparation to achieve an even particulate distribution on the membrane suitable for other applications. Membrane evaluation using standard membranes, described in this document, is an alternative technique to counting with either an optical microscope (ARP598) or an automatic particle counter (ISO 11500). The latter particle counting procedures are considered more rpecise. This procedure shall not be used as an alternative to particle counting unless agreed to by the customer since the results by this procedure may differ from those by particle counting, even though the standard membrane correlates to a specific particle count.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Purchase more aerospace standards and aerospace material specifications and save! AeroPaks off a customized subscription plan that lets you pay for just the documents that you neeed, when you need them.

Get Involved

Want to participate in updating this standard?