Abstract: The electronic microprocessor controller of a sterilizer includes a circuit board functionally controlled by software. The software includes a fist user operation mode for normal operation of the sterilizer. A diagnostic operation mode is initiated by insertion of a jumper in the circuit board, and provides for repetitive cycle operation without opening the door, quickly advancing to a cycle phase, without completion of intervening phases, printing of variables not available in the user operation mode, and calibration of the circuitry.

Abstract: Apparatus and methods for detecting pressure changes within the chamber of a pressure vessel are disclosed. The apparatus includes a pressure transducer which is gauge-referenced to atmospheric pressure and has bi-directional capability of determining pressure changes above and below atmospheric pressure. The transducer is structured to provide frequency output and is therefore connected directly to a microprocessor. The microprocessor includes structure programmed to compensate for variations in existing ambient atmospheric pressure.

Abstract: The application is directed to methods and apparatus for venting a pressurized sterilizer chamber having a liquid load within it. A sterilizer chamber is provided with a pressure sensor for sensing the chamber pressure and a vent channel with an associated vent valve. The vent valve is opened to vent pressure from the chamber, and has an orifice providing a maximum flow coefficient substantially larger than a standard bleed valve. A microprocessor-based sterilizer controller monitors chamber pressure and opens and closes the vent valve. The venting phase is regulated by means of a series of vent cycles. An individual vent cycle is intiated by starting a software timer to time a preset interval. The controller records a starting chamber pressure and opens the vent valve. The controller monitors the chamber pressure, and when the pressure has dropped from the starting pressure by a selected maximum amount, closes the vent valve until the timer interval has elapsed.

Abstract: A temperature monitoring system provides a first, coarse temperature output signal, and a second, fine temperature output signal based on the first, coarse output signal. The fine output signal has a higher resolution than the coarse output signal, and permits fine temperature control of an apparatus at a variable control output. The fine output signal is automatically calibrated upon switching from the coarse to the fine signal.