# Vacuum pump-down time
# Scope: Constant pumping speed, isothermal fixed vessel, no leaks/outgassing.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

volume = 10 L
pumpingSpeed = 20 L/min
initialPressure = 100 kPa
finalPressure = 20 kPa

duration := volume/pumpingSpeed*log(initialPressure/finalPressure) [s]

check pump down budget: duration <= 60.0 s

scenario alternative: volume = 8 L