Steam sterilization apparatus and control system

摘要

A steam sterilization apparatus (10) includes an electronic control system having a main control circuit (C) including a central processing unit (68), an input device (36), and output devices (24,28) provided on a single circuit board (22) which is attached to a front bezel (16) of the sterilizer (10). The sterilizer (10) includes a flash steam generator (56). The main control circuit (C) implements an over-temperature feedback circuit (160) that disconnects the heating elements (162) in the steam generator (56) from electrical power when an over-temperature condition is detected. Isolated feedback is provided to the central processing unit (68) confirming the heating element disconnection operation. The control system includes error switches (82, 86, 88) that detect various error conditions. Upon an error condition being detected, the steam supply to the steam sterilization chamber (12) and/or to the pressurized steam seal (42) of the apparatus (10) is halted. The main control circuit (C) implements a feedback circuit (150) confirming the steam shutdown procedure. The main control circuit (C) also includes a ratiometric analog input circuit (74) that eliminates temperature drift in analog measurements.