ISO 4407-2002 pdf free download

ISO 4407-2002 pdf free download.Hydraulic fluid power — Fluid contamination — Determination of particulate contamination by the counting method using an optical microscope. 4 Counting principle A known volume of hydraulic liquid is vacuum filtered through a membrane filter to separate the contaminants from the liquid. The particles are examined microscopically using either incident light or transmitted light, after making the membrane filter transparent, to size and count the contaminant particles according to their largest dimension. 5 Apparatus 5.1 Drying oven, able to control temperature up to (70 ± 2) °C. 5.2 External lamp, of variable intensity, where oblique illumination of the specimen stage is required. 5.3 Filter holder, comprising: a funnel, 300 mL capacity with suitable calibrated volumetric graduations [e.g. (25 ± 2) mL]; a suitable cover for the funnel (e.g. a Petri dish); a clamping device; a suitable base to support the membrane filter; a means of dissipating any static electricity generated during the filtering process. 5.4 Graduated cylinders, for measuring out the volume of test liquid. Either the accuracy should conform to ISO 4788 or a sample bottle calibrated with suitable volumetric graduations can be used. The accuracy of graduation should be ± 2 %. 5.5 Image analysing equipment, comprising a microscope base with a range of objective lenses and trinocular head for attaching a video camera connected to a suitable video monitor. The output of the video camera is fed to a computer which recreates a video digital image of the view, where the particles are sized and counted using specially developed software. Although a manual X-Y stage and focus can be used, it is recommended that these be motorized and controlled by the software as this enables the particles to be localized. 5.6 Membrane filters, compatible with the sample liquid and any solvents or chemicals used in the processes. Normally, the membrane filter shall be of 47 mm diameter, white, gridded (each grid square with sides 3,08 mm ± 0,05 mm and an area equal to 1/100th of the effective filtration area), with a pore size less than 1,5 µm, used for manual counting down to 2 µm. A 47 mm diameter, white, ungridded membrane filter with a pore size less than 1,5 µm is recommended for image analysis. Membrane filters of different diameters are permissible. It is permissible to use membrane filters of different nominal pore size to account for the minimum size of...