PD ISO/TR 4808 is a document on hydraulic fluid power. PD ISO/TR 4808 describes a method for the interpolation of particle concentration and filter Beta Ratio data when results are not otherwise available at the desired particle sizes.
PD ISO/TR 4808 is applicable for assessing conformance with existing fluid cleanliness and filter Beta Ratio specifications whereby the specification and actual test results are provided in different units of particle size, for example, the specification is in μm(c), but the particle counts, or Beta Ratio data are in units of μm(b).
PD ISO/TR 4808 is also applicable when particle sizes in specifications and available data use the same units of particle size, but do not correspond to the same sizes, for example, when particle counts at 20 μm(c) are specified, but data was collected at 21 μm(c).
PD ISO/TR 4808 on hydraulic fluid power is useful for:
Hydraulic fluid power is primarily used for transporting fluids from one location to another. PD ISO/TR 4808 introduces a method that allows the interpolation to intermediate particle sizes within the range of existing data and does not permit extrapolation to particle sizes outside the range of available data. The resultant interpolated values can be used to convert cleanliness level or filter performance specifications and data from μm(b) to μm(c).
The interpolation of μm(b) to μm(c) data involves Mathematical conversion of μm(b) sizes to μm(c), constrained cubic spline interpolation of the data using the resultant μm(c) sizes, visual validation of the interpolated results and determination of interpolated particle concentrations or Beta Ratios for μm(c) at the particle sizes of interest.
With PD ISO/TR 4808 you can use the interpolation method to measure hydraulic fluid power.
ISO/TR 4808