Liquid particle counters are used to determine the quality of the liquid passing through them. The size and number of particles can determine if the liquid is clean enough to be used for the designed application. Liquid particle counters can be used to test the quality of drinking water or cleaning solutions, or the cleanliness of power generation equipment, manufacturing parts, or injectable drugs.
Liquid particle counters are also used to determine the cleanliness level of hydraulic fluids, the reason being that 75-80% of hydraulic breakdowns can be attributed to contamination. There are various types, installed on the equipment, or portable units that can be transported to site, e.g., a construction site, and then used on the machine, e.g., a bulldozer, to determine fluid cleanliness. By determining and monitoring these levels, and following a proactive or predictive maintenance program, the user can reduce hydraulic failures, increase uptime and machine availability, and to reduce oil consumption. They can also be used to assure that hydraulic fluids have been cleaned using filtration, to acceptable or target cleanliness levels. There are various standards in use in the hydraulic industry, of which ISO 4406:1999, NAS1638 and SAE AS 4059 are probably the most common.