This part of ISO 14085 defines a reference method for determining the level of cleanliness of new filter elements for use in aircraft hydraulic systems, after production prior to shipment, or prior to installation in the circuit.

It applies to filter elements used on systems requiring fluid cleanliness conditions defined in the particular specification.

The tests data resulting from application of this part of ISO 14085 can be used to compare the cleanliness of aerospace hydraulic filter elements.