Abstract
This International Standard specifies methods for determining the level of particulate contamination in liquids used in hydraulic systems by counting the number of particles deposited on the surface of a membrane filter using an optical microscope. It includes particle counting by two manual methods and image analysis, using either transmitted or incident lighting systems.
Particle sizes greater than or equal to 2 micrometres can be sized and counted by this method, but the resolution and accuracy of the results will depend upon the optical system used and the capabilities of the operator.
All hydraulic fluids with a wide range of contamination levels can be analysed according to this International Standard. However, the counting uncertainty at the larger particle sizes increases if the volume filtered is reduced to allow smaller sized particles to be counted, where a fine precipitate or a high particle concentration is present.
General information
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Status: PublishedPublication date: 2002-04Stage: International Standard to be revised [90.92]
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Edition: 2Number of pages: 14
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Technical Committee :ISO/TC 131/SC 6ICS :23.100.60
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Life cycle
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Previously
WithdrawnISO 4407:1991
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Now
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Will be replaced by
Under developmentISO/DIS 4407