Practice of counting particles of solid matter in groups based on relative size. Frequently used in engineering a filter to a specific task or to evaluate the performance of a filter under specific operating conditions. When used as data to engineer a filter, proper consideration can be given the type of medium to be used, expectant life of the medium and the true cost of operation.
A routine test. Important because too high even once can lead to shorter fluid lives, servo and/or solenoid valve problems with sticking and screen/filter blockage. Resample and determine source if still high. Often expressed in terms of the number of particles in specified size ranges for a 100ml sample or as an ISO Cleanliness Code.
The number of particles detected (or reported) in a given volume of air.
The number of particles present greater than a particular micron size per unit volume of fluid often stated as particles 10 microns per milliliter.
the number of particles present greater than a particular micron size per unit volume of fluid. Selected methods of particle counting are: automated optical, where particles are directly sized and counted using the dispersion or blockage of light created by a solid particle passing between a light source and a sensor; Image analysis, where stationary particles are directly sized and counted under the microscope by manual or automated systems; Electrical resistance, which measures the volume of a particle as it passes through an orifice in an electrically conductive liquid; Flow decay, where count and size data is extrapolated from a standard equation applied to the rate at which flow decreases through a screen as particles block it.
The results of a microscopic examination of treated water with a special "particle counter" which classifies suspended particles by number and size.
Test method which measures the size of a particle as the diameter of a circle having an equivalent area. In an automated counter a collimated beam of light is directed through the liquid onto a photo detector. Whenever a particle traverses the light beam, a portion of the light is interrupted, producing a specific reduction in the amount of light reaching the photo tube. The amplitude of the resultant current pulse is proportional to the particle size giving a resultant count.
