For particulate filtration, this is the number of particles going in divided by the number of particles going out. The ratio varies with particle size, with differential pressures and with the age of the filter element. For the latter, some get better with age but most will be worse. It is often determined in a Multipass Beta Filter Test per ISO 4572. However, it should be noted that field sampling on in/out samples has seldom yielded as good a beta ratio as those quoted in sales material.
The ratio of the inside of the diameter throat of the venturi to the inside diameter of the pipe at the plane of the upstream Pressure Taps.
Efficiency measurement of any filter expressed by the number of particles of a given size upstream of the filter, divided by the number of particles of that size downstream of the filter. ( 099)
The ratio of the number of particles of a given size and larger upstream of a filter to the number of particles of the same size and larger downstream.
The ratio of the number of particles greater than a specified micrometer in the influent fluid to the number of particles larger than the specified micrometer in the effluent fluid.
The ratio of the diameter of a pipeline constriction to the unconstricted pipe diameter.
the ratio of the number of particles greater than a given size entering a filter to the number of particles greater than the same size leaving the filter, under specified test conditions.
For a single orifice the beta ratio is the ratio of the orifice bore diameter to that of the upstream pipe diameter. However, since in burner designs typically there is more than one orifice at a riser pipe exit, the beta ratio is equal to the square root of the ratio between total area of the fuel ports to that of the upstream pipe area.
Measurement of filter retention efficiency. Ratio of particles exposed to a filter (as feed stream) to particles present in the filtrate.
