d l n P d T = Δ H v a p R T 2 {\displaystyle {\frac {dlnP}{dT}}={\frac {\Delta H_{vap}}{RT^{2}}}}
假設 δHvap 是常數，則方程式可以改寫成：
l n P = − Δ H v a p R T + c o n s t a n t {\displaystyle lnP={\frac {-\Delta H_{v}ap}{RT}}+constant}
