ISO 4406:2021, ISO/TR 10949:2012, NFPA T2.14.1-2005

Fluid Cleanliness Evaluator

Evaluate a hydraulic fluid sample (ISO 4406 code) against the standard cleanliness target for the system type. Returns compliance status, excess contamination per channel, and required particle count reduction ratio to achieve the target.

FORMULA

Δ = N_current − N_target  (per channel)
Compliant when Δ ≤ 0 for all three channels
Reduction ratio = 2^Δ  (each step = 2× particle count)

VARIABLES

N_currentCurrent ISO 4406 range code from fluid sample

N_targetTarget ISO 4406 range code for the system type

ΔRange code excess (positive = non-compliant) [range steps]

2^ΔRequired particle count reduction ratio to reach target

ASSUMPTIONS

· The fluid sample is representative of the system in steady-state operation (not during start-up or after maintenance).

· Particle counts are obtained by APC per ISO 4406:2021 §7 at the three standard channels.

· Target codes are based on component cleanliness sensitivity, not fluid quality requirements.

LIMITATIONS

· Cleanliness targets are component-specific. A system may contain multiple component types requiring different targets — use the most stringent target as the system target.

· Achieving the target cleanliness requires both a filtration system capable of reaching the target and control of ingression sources.

· The evaluator does not account for fluid chemistry, water content, or varnish — only particle contamination.

CALCULATOR

System type

N4 (≥4 µm code)

N6 (≥6 µm code)

N14 (≥14 µm code)

Compliance statusNON-COMPLIANT

Δ N4 (≥4 µm)+3 steps

Δ N6 (≥6 µm)+2 steps

Δ N14 (≥14 µm)+2 steps

Required ≥4 µm count reduction8×

Required ≥6 µm count reduction4×

Required ≥14 µm count reduction4×

RELATED STANDARDS

iso-4406 →iso-16889 →

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

RELATED TECHNOLOGIES

NANOFORCE™

SYNTRAX™

VALIDATION: ISO/TR 10949:2012 Table 1 (component cleanliness targets); NFPA T2.14.1-2005 §5 (hydraulic system cleanliness levels); Parker Hannifin Contamination Control Guide. · SOURCE: ISO 4406:2021 and ISO/TR 10949:2012 · STATUS: VALIDATED