ISO 4405:1991 pdf download.Hydraulic fluid power - Fluid contamination -Determination of particulate contamination by the gravimetric method
I Scope
ISO 4405:1991 pdf download defines two gravimetric methods for determining the contamination level of fluids used in hydraulic fluid power systems.
2 NormatIve references
The following standards contain provisions which, through reference In this text, constitute provisions of this lriteriiational Standard. At (lie (line of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to Investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 3938:1986, Hydraulic fluid power — Contamination analysis — Method for reporting analysis data.
ISO 4021:1977, Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from lines of an operating system.
ISO 5598:1985, Fluid power systems and components
— Vocabulary.
3 DefInitions
For the purposes of this International Standard, the definitions given in ISO 5598 apply.
4 PrInciple
Filtration of a known volume of fluid under vacuum conditions through one or two Identical superimposed filter membranes. The increase in mass of the membrane or the dilterence in mass of the two membranes after filtration represents the solid Impurity content.
5 Apparatus
5.1 Filter holder, comprising
— a graduated glass funnel, of 250 ml capacity;
— a clampIng device;
— a glass base including a sintered glass or stainless steel filter-holder grid.
5.2 Cap for the funnel, for example, the lid of a Petri
dish.
5,3 FIlter membranes, of 47 mm diameter, white, non-gridded and compatible with the fluid to be analysed and with the rinsing chemicals. Reference membranes have a 0,8 pm pore size. Any other pore size used shall be stated.
5.4 FIlter flask.
5.5 Device, for establishing a vacuum of 86,6 kPa (0,866 bar”) (I.e. 650 mmHg).
5.6 Filtered-solvent dispenser, (I.e. a pressure- operated system which discharges the solvent through a filter membrane).
5.7 Flat-ended tweezers, of stainless steel.
5.8 Petrl dishes, glass, 150 mm in diameter.
5.9 Glass flasks, narrow-necked and with screw caps, at least 100 ml in capacity, with an Indelible gauge mark at the level of 100 ml.
8.1 Ensure that the samples are as representative as possible of the fluid under consideration.
Ensure that the sampling procedure to be devised by each society or laboratory allows good repeat-ability.
Check the sampling procedure periodically by col-lecting two samples and making two different measurements on the same sample.
8.2 Extract 100 ml of fluid from an operating hy-draulic fluid power system, by the method described in ISO 4021.
NOTE 2 This volume may, however, be modified to suit very different contamination levels.
In all cases, the sample volume used for the meas-urement shall be stated with a tolerance of 1 %.ISO 4405 pdf download.