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ISO 4406:2021

ISO 4406 Cleanliness Code Converter

Convert particle counts per mL (≥4 µm(c), ≥6 µm(c), ≥14 µm(c)) to ISO 4406:2021 three-part cleanliness codes, or decode existing codes to particle count ranges. Includes system compliance check against standard target codes.

FORMULA

Range code N = ceil(log₂(count)) for count > 1 Range code N = 1 for count ≤ 1 Code format: N₄ / N₆ / N₁₄

VARIABLES

NISO 4406 range code [dimensionless (integer)]
N₄Range code for particles ≥ 4 µm(c) per mL
N₆Range code for particles ≥ 6 µm(c) per mL
N₁₄Range code for particles ≥ 14 µm(c) per mL
countCumulative particle count at the specified size [particles/mL]

ASSUMPTIONS

· Particle count is measured by an APC calibrated per ISO 11171:2020.

· Counts are reported as cumulative (all particles ≥ the stated size).

· The (c) designation indicates optical calibration per ISO 11171.

LIMITATIONS

· ISO 4406 reports contamination level, not contamination source or composition.

· Range codes are logarithmic — a 1-code difference represents a 2× count change.

· The three-channel code only covers 4, 6, and 14 µm(c); finer or coarser particles are not represented.

· Particle count must be measured at ISO 4406-defined size channels using a calibrated APC.

CALCULATOR

≥4 µm(c) count [/mL]
≥6 µm(c) count [/mL]
≥14 µm(c) count [/mL]
ISO 4406:2021 Code17/14/10
≥4 µm range code (N4)17
≥6 µm range code (N6)14
≥14 µm range code (N14)10

RELATED STANDARDS

iso-4406 →iso-16889 →iso-11171 →

RELATED ARTICLES

iso-4406 →fluid-cleanliness →hydraulic-contamination-sensitivity →

RELATED TECHNOLOGIES

NANOFORCE™

SYNTRAX™

VALIDATION: Parker Hannifin Contamination Control Technical Guide; Eaton Vickers Contamination Analysis Guide (M-2994-S Rev. A). · SOURCE: ISO 4406:2021 · STATUS: VALIDATED