fluids Hydraulic fluids and oils must meet specific ISO 4406 standards, the application of hydraulic fluids vary from aerospace and turbine cooling and lubrication to heavy machinery, the build up and presence of particles can cause failure of bearings, pumps and seals. Water Water is a universal product with an unlimited number of applications and can be contaminated due to intentional interactions with processes or unintentional and seasonal variances. Monitoring the quality of water using particle counters, either by spot checking at a sample location or continuously monitoring a distribution system allows quality engineers to react to changes in the processes where water is being used. Particle counters are used to determine the filtration rates, chemical addition requirements, flushing intervals, sedimentation information, cooling flowrates and many other process variables that allow for continuous feedback ensuring a consistent quality of water to a process. Environmental Particulates exist in the atmosphere at concentrations that can be deleterious to health and have been proven to factor into causes of many airborne illnesses such as asthma. Types of atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM10, which are coarse particles with a diameter of 10 micrometers (μm) or less; fine particles, designated PM2.5, with a diameter of 2.5 μm or less; ultrafine particles; and soot. Particle counters are used to monitor atmospheric contamination levels of these suspended particulates allowing for the reduction of particles associated with a specific source (combustion) or technology (power generation). The modelling of particulate data from particle counters distributed globally gives trend information to the state of quality of air and its migration. See also Particle mass analyser Particulate matter sampler Aerosol mass spectrometry References External links www.iest.org — Institute of Environmental Sciences and Technology Meteorological instrumentation and equipment Counting instruments Particle detectors Aerosols Occupational safety and health