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THE PROCESS
When sterilizing liquids, the temperature is measured with a tempera-
ture sensor in the load. The condition for countdown of sterilizing time
is that both temperature sensors in the chamber and the sensor in the
load indicate the programmed sterilizing temperature.
Post-treatment
The purpose of the post-treatment is to normalize the temperature and
moisture content of the goods. All goods except liquids are therefore
exposed for a certain time to a vacuum below 70 mbar (a). After such
post-treatment. textiles may appear to increase in weight by about 1%.
This represents the normal addition of water that occurs during steam
autoclaving process.
Post-treatment of liquids that have been sterilized in open or half-closed
containers consists of a self-cooling period. During this period the pres-
sure and temperature are lowered very slowly until the temperature is
well below the boiling point of the liquid. This process is speeded up by
applying a slight vacuum to the chamber when its pressure approaches
atmospheric.
Pressure equalization from vacuum takes place by admitting atmos-
pheric air into the chamber via a filter that prevents bacteria from enter-
ing the chamber. The efficiency of the filter is 99.998% for particles of
the order of 0.3 micron (0.0003 mm) in size.
The sterilizer door is kept closed by the door gasket until the pressure in
the chamber is equal to atmospheric pressure.
Process adaptation
A large number of factors such as type of goods, goods carrier, packag-
ing material, etc. affect the result of the process. The control equipment
offers a number of features that can be used to optimize the processes to
suit the requirements of different customers. For further information,
see "User-programmable functions" in the TECHNICAL MANUAL.
NOTE: Liquids must only be processed in sterilizers which
have a program for this type of load.
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