Measured Filter Flow & Pressure Drop Interpolation
Query a measured filter pressure-drop curve using piecewise linear interpolation between adjacent test points. Reverse mode queries flow at a measured-range pressure drop.
Same filter element, fluid, viscosity, temperature, condition and measurement boundaries required. Use actual flow at test conditions. No extrapolation, no Darcy parameter inference and no certified performance rating.
Interpolated result
Formula
For neighboring points (Q₁, Δp₁), (Q₂, Δp₂): f=(Q−Q₁)/(Q₂−Q₁); Δp=(1−f)Δp₁+fΔp₂. Reverse mode exchanges the flow and pressure axes. Only queries within the measured endpoints are accepted.
Frequently asked questions
Is linear interpolation a physical pressure-drop model?
No. It connects adjacent measurements with straight segments. Curvature between measurements may cause error; use more measured points and validate important operating points.
Can I mix a clean and a fouled filter curve?
No. Use data from comparable element conditions. Do not merge different filters or temperatures into one curve.
Why are non-monotonic pressure readings rejected?
This tool requires an unambiguous inverse query. Review test noise, units, pairings and conditions rather than having the tool silently change the measurements.
Can I query beyond the last test point?
No. Extrapolation is blocked. Obtain additional measurements or use a validated physical model.
Does this include piping and housing losses?
Only if those losses are included in the entered measurements. Preserve the same pressure-tap boundaries for every point and label the source accordingly.
Does the calculator average test results or uncertainty?
No. It uses each entered pair directly. No statistical confidence or standard-compliant overall test result is assigned.
