Hydrogen Purity & Dew Point

Estimate moisture content and dew points from a purity specification. ISO 14687 quality targets included. Free - no account required.

Hydrogen purity to dew point

Estimate moisture content and dew points from a purity specification. Enter the dry gas purity and line pressure to see the equivalent dew point and ppm values.

Moisture is assumed to be water vapour. Dew point uses an Arden Buck correlation.

Gas data

Gas type
Hydrogen
Molecular weight
2.016 g/mol
Line pressure
30 bar
Parts per million
10 ppm(v)
Parts per million by mass
89 ppm(w)

Dew point & absolute moisture

Dew point (observed)
-80 °C
Dew point @ 1.013 bar
-96 °C
Absolute humidity
0.000 g/m³ @ 15 °C
Moisture loading
0.00 lb/MMSCF

Outputs are rounded. For very dry gas (<1 ppm) dew point is reported as below the calculation range and lb/MMSCF uses the same standard reference conditions.

Hydrogen quality targets under ISO 14687

Check your calculated dew point and impurity levels against the limits for your target application. Figures reference ISO 14687:2019 and related application guidance.

Application ISO 14687 Grade Min. Purity Total Impurities Moisture Limit Dew Point (@ 1 bar) Related Standards
Fuel cell vehicles Grade C 99.97% ≤300 ppm(v) ≤5 µmol/mol ~−73 °C ISO 19880-1, SAE J2601/J2719
Stationary fuel cells Grade D 99.9% ≤1,000 ppm(v) ≤10 µmol/mol ~−68 °C ISO 22734, ISO 19880-8
Industrial & heat Grade A 99.5% ≤5,000 ppm(v) ≤50 µmol/mol ~−47 °C ISO/TR 15916, EN 16726

More engineering tools

Use storage sizing and flow converters alongside purity calculations for a complete engineering picture.

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