BS ISO 11500:2008

Hydraulic fluid power. Determination of the particulate contamination level of a liquid sample by automatic particle counting using the light-extinction principle. | Status: Superseded, Withdrawn

1 Scope This International Standard specifies an automatic particle counting procedure for determining the number and sizes of particles present in hydraulic-fluid bottle samples of clear, homogeneous, single-phase liquids using an automatic particle counter (APC) that works on the light-extinction principle. This International Standard is applicable to the monitoring of

1. a) the cleanliness level of fluids circulating in hydraulic systems,
2. b) the progress of a flushing operation,
3. c) the cleanliness level of support equipment and test rigs,
4. d) the cleanliness level of packaged stock.

NOTE 1 Measurements can be made with particles suspended in the original liquid or in a sample of the liquid diluted with a compatible liquid to reduce coincidence error.

NOTE 2 The presence of a fluid interface obstructs the light beam and gives false signals.