ISO 11943-2021 pdf download.Hydraulic fluid power一Online automatic particle-counting systems for liquids – Methods of calibration and validation.
Throughout this document, the use of pm(c) means that particle size measurements are carried out using an automatic particle counter that has been calibrated in accordance with either ISO 11171 or this document and particle size reported as defined in ISO 11171.
Previous editions of ISO 11171 allowed for calibration in pm or pm(b) notations. Conformance with ISO 11171:2020 and later requires pm(c) only.
5 Test equipment
5.1 Liquid automatic particle counters, requiring either calibration or verification, or a particle counter with two independent sensors.
5.2 A reference particle counter, which shall be calibrated with a reference material in accordance with ISO 11171.
5.3 ISO medium test dust (ISO MTD) concentrate, which shall be in accordance with ISO 12103-1,category A.3. dried at 110°C to 150 °C for at least 1 hand for use in the test system, mixed in the test fluid,mechanically agitated, then dispersed ultrasonically with a power density of 3 000 W/m2 to 10 000 W/m2.
NOTE This standard test dust is used for filter test purposes in ISO 16889.
5.4 Test fluid, which shall be as specified in ISO 16889.
5.5 Hydraulic equipment, comprising:
a) a reservoir, pump, liquid temperature control system and instrumentation which are capable of meeting the validation requirements of Clause 8
b) a clean-up filter capable of providing an initial fluid contamination level of less than 50 particles per millilitre at the smallest particle size that will be validated or less than 2 % of the expected number of counts;
c a configuration which does not alter the contaminant distribution over the anticipated test duration (refer to ISO 16889);
d) fluid sampling sections which shall be in accordance with ISO 4021;
e) a configuration which supplies contaminated liquid to the particle counters under constant flow and temperature within the limits of Table 1.
NOTE 1 A multi-pass Lest rig (see ISO 16889) can be used provided it has been validated in accordance with Clause 8.
NOTE 2 An alternative typical configuration which has proven satisfactory is given in Annex A.
5.6 Hydraulic circuit, containing dilution equipment, if required, for online counter adaptation to a filter multi-pass test stand.
For typical hydraulic circuit configurations which have proven satisfactory, refer to Annex B.ISO 11943 pdf download.