The precise conditions needed to achieve pasteurization and sterilization are controlled by a programmable logic controller (PLC) in millisecond intervals. This level of control in modern units has allowed for the simplification of autoclave technology to the point where heavy and potentially dangerous pressure vessels are not needed, and sterilization conditions are reached by depressing the conversion cell and continuing to evaporate moisture from the product under negative pressure. The result is a statistically safer and more reliable machine, which is also smaller and lighter than older autoclaves.