Concept:
Humidity ratio \(\left( w \right) = \frac{{0.622\;Pv}}{{{P_{total}} - Pv}}\;kg/k{g_{da}}\)
Calculation:
Given:
Ptotal= 750 mm of Hg. & Pwater = 20 mm of Hg.
To find humidity ratio.
humidity ratio \(\left( w \right) = \frac{{0.622\;Pv}}{{{P_{total}} - Pv}}\;kg/k{g_{da}}\)
\(w = \frac{{\left( {0.622} \right)20}}{{\left( {730} \right)}} = 0.01704\;kg/kgda\)
w = 17.04 g/kgda