Practitioner tool
Wet to Dry Basis Converter (Stack Moisture Correction)
Convert a stack concentration between wet and dry basis using the moisture fraction (Bws).
Some analyzers measure on a wet basis; most limits are on a dry basis. The correction uses the stack gas moisture fraction from a moisture determination such as EPA Method 4.
Wet to dry basis calculator
Bws × 100. For example 12 for 12% moisture.
- Dry basis
- 45.455 same unit as entered
Steps
- C(dry) = 40 ÷ (1 − 0.12) = 45.455
Questions engineers ask
Where does Bws come from?
From a moisture determination during the test, such as EPA Method 4, or from a moisture monitor. Use the value measured at the same time as the concentration.
More converters: ppm to lb/hr, O2 correction, ppm to lb/MMBtu, lb/MMBtu to lb/hr, g/hp-hr to lb/hr, lb/hr to tons/yr, ppm to mg/m³.
How this works
Formula
- C(dry) = C(wet) ÷ (1 − Bws)
- C(wet) = C(dry) × (1 − Bws)
Before you rely on the number
- Bws is the water vapor fraction of the stack gas by volume, as a decimal.
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