ISO 21018-1:2024

This document specifies methods and techniques that are applicable to the monitoring of particulate contamination levels in hydraulic systems that cannot be calibrated in accordance with ISO 11171. It also describes the relative merits of various techniques, so that the correct monitor for a given application can be selected.
The techniques described in this document are suitable for monitoring:
a)       the general cleanliness level in hydraulic systems;
b)       the progress in flushing operations;
c)        support equipment and test rigs.
This document can also be applicable for other liquids (e.g. lubricants, fuels and process liquids).
NOTE            Instruments used to monitor particulate contamination that cannot be calibrated according to ISO 11171 are not considered as or claimed to be particle counters, even if they use the same physical principles as particle counters