S=Vt×ln(P1P2)cap S equals the fraction with numerator cap V and denominator t end-fraction cross l n open paren the fraction with numerator cap P sub 1 and denominator cap P sub 2 end-fraction close paren : Required pumping speed (e.g., : Total system volume (chamber + piping). : Desired evacuation time. : Initial and target pressures. 2. Steady-State Gas Load (
: Capacity is often rated differently depending on the gas being pumped (e.g., water vapor vs. argon). vacuum pump capacity calculation xls