ASP STERRAD 100, Service Manual, Page: 116 / 309

Theory of Operation
The STERRAD Sterilization Process occurs in the following manner:
F
The items to be sterilized are placed in the sterilization chamber, the
chamber is closed, and a vacuum is drawn.
F
An aqueous solution of hydrogen peroxide is injected into the
chamber where it vaporizes, surrounding the items to be sterilized.
F
After a period of hydrogen peroxide diffusion, the pressure is reduced
in the chamber. The formation of a low-temperature gas plasma is
initiated by applying radio frequency (RF) energy to create an electric
field.
F
In the plasma state, the hydrogen peroxide vapor beaks apart into
reactive species that include free radicals. The combination of
hydrogen peroxide vapor and plasma, safely and rapidly sterilizes
most medical instruments and materials without leaving toxic
residues.
F
Following the reaction, the activated components lose their high
energy and recombine to form primarily oxygen, water and other
non-toxic by-products.
F
When the process is complete, the RF energy is turned off, the
vacuum is released and the chamber is returned to atmospheric
pressure by venting through a High Efficiency Particulate Air (HEPA)
filter. The items within are sterilized and ready for use.
Figure 6-1. User Interface Block Diagram
Theory of Operation User Interface and Control Subsystems
ASP Service Guide rev D. STERRAD® 100 Sterilizer 6-3