ISO 16889:2022

Beta Ratio ⇄ Filtration Efficiency Calculator

Bidirectional conversion between ISO 16889 Beta ratio (β_x(c)) and single-pass filtration efficiency (E_x(c)). Enter either a Beta ratio or an efficiency percentage; the calculator returns the inverse quantity and downstream particle concentration.

FORMULA

β_x(c) = N_upstream / N_downstream
E_x(c) = (1 − 1 / β_x(c)) × 100 %
β_x(c) = 1 / (1 − E_x(c) / 100)

VARIABLES

β_x(c)Beta ratio at particle size x µm(c)

N_upstreamCumulative upstream particle count ≥ x µm(c) per unit volume [count/mL]

N_downstreamCumulative downstream particle count ≥ x µm(c) per unit volume [count/mL]

E_x(c)Single-pass filtration efficiency at particle size x µm(c) [%]

x µm(c)Particle size designation using optical calibration per ISO 11171 [µm(c)]

ASSUMPTIONS

· Beta ratio is measured under steady-state flow conditions using ISO Fine Test Dust (ISO 12103-1 A2).

· Upstream and downstream counts are measured simultaneously by calibrated APCs per ISO 11171.

· The ratio is single-pass efficiency — multi-pass or steady-state cleanliness requires separate analysis.

LIMITATIONS

· Beta ratio is test-condition specific: values change with flow rate, pressure, and test dust type.

· Beta ratio does not account for filter bypass flow or unfiltered leakage paths.

· Efficiency at one particle size does not predict efficiency at other particle sizes.

· Very high Beta values (β > 1000) are difficult to measure accurately — APC downstream count approaches the detection limit.

CALCULATOR

Beta ratio β

Beta ratio β200.0

Single-pass efficiency99.500 %

Particles passed0.5000 %

RELATED STANDARDS

iso-16889 →iso-11171 →iso-4406 →

beta-ratio →iso-16889 →testing-and-validation →

RELATED TECHNOLOGIES

NANOFORCE™

SYNTRAX™

MACROCORE™

VALIDATION: ISO 16889:2022 Annex A — reference data from certified multipass test reports (Pall Corporation FP2B-A, Parker Hannifin ISO-16889 certification series). · SOURCE: ISO 16889:2022 · STATUS: VALIDATED