ISO 4407:2002 Hydraulic fluid power - Fluid contamination - Determination of particulate contamination by the counting method using an optical microscope
This International Standard specifies methods for determining the level of participate 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 ≥ 2 μn can be sized and counted by this method, but the resolution and accuracy of the results wiB 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.
ISO 4407:2002 Referenced Document
ISO 14644-1:1999 Cleanrooms and associated controlled environments - Part 1: Classification of air cleanliness
ISO 3722 Hydraulic fluid power; Fluid sample containers; Qualifying and controlling cleaning methods
ISO 4406:1999 Hydraulic fluid power - Fluids - Method for coding the level of contamination by solid particles
ISO 4788 Laboratory glassware - Graduated measuring cylinders*, 2005-05-01 Update
ISO 5598 Fluid power systems and components — Vocabulary*, 2020-01-06 Update
ISO 4407:2002 history
2002ISO 4407:2002 Hydraulic fluid power - Fluid contamination - Determination of particulate contamination by the counting method using an optical microscope
1991ISO 4407:1991 Hydraulic fluid power; fluid contamination; determination of particulate contamination by the counting method using a microscope