ISO 4405:1991 pdf download – Hydraulic fluid power – Fluid contamination – Determination of particulate contamination by the gravimetric method
1 Scope
This International Standard 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 International Standard. At the time of publi- cation, the editions indicated were valid. All stan- dards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of ap- plying the most recent editions of the standards in- dicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 3938:1986, Hydraulic fluid power – Contami- nation 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 sysfems and components – Vocabulary.
3 Definitions
For the purposes of this International Standard, the definitions given in IS0 5598 apply.
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.
5.13 Alpha-ray ionlser, to prevent the collection of dust during the weighing operation, placed under the balance scale incorporating the filter and pro- jecting from beneath it.
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 IS0 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 %.
9.1.1 Take two filter membranes (5.3) out of their packings using the tweezers. Mark them using a ball-point pen with the letters E (test) and T (gauge). Place both membranes on the filter holder (5.1 ), with membrane Tunder membrane E. Install the funnel and fix the whole assembly by means of the clamp- ing device. Rinse the funnel with sufficient filtered solvent C(6.2) and (6.3) to ensure that the funnel and the membranes are fully wetted. Evacuate until the filter membranes are dry. Remove the clamp and the funnel and cease evacuation.