Establishing and ascertaining desired air removal in steam sterilization

Claim 1

Process for steam sterilization of goods utilizing steam flow through a chamber to facilitate removal of air and providing for determination of effective air removal by correlating measured chamber conditions with steam-table established data for the dependent variables of pressure and temperature for saturated steam, comprising the steps of providing a chamber capable of operating at pressures above atmospheric, injecting steam into the chamber while providing for removal of chamber atmosphere through a chamber vent opening such that chamber pressure increases above atmospheric pressure, such chamber vent opening being held constant in a substantially wide open configuration during removal of chamber atmosphere, providing for use of predetermined steam-table data for the dependent variables of pressure and temperature for saturated steam, controlling the value within the chamber of one of such dependent variables while measuring at least intermittently the value within the chamber of the remaining of such dependent variables during an air removal load conditioning phase prior to reaching desired steam sterilization exposure conditions, such control of the value within the chamber of the one dependent variable and such measurement of the remaining dependent variable being carried out until respective values of each within the chamber substantially correspond to the predetermined steam-table values for each thus completing air removal and ensuring that substantially all air has been removed, then rapidly pressurizing the chamber for steam sterilization exposure and closing such constant opening chamber vent, maintaining the constant opening chamber vent closed until completion of desired sterilization, and upon completion of desired sterilization exposure, exhausting the chamber to return chamber pressure to substantially atmospheric pressure.