| 摘要 |
PURPOSE:To prevent the involution of air, by providing a sensor for detecting the internal pressure of a vacuum container, a means for storing a pressure detection value under the open state of the vacuum container and a control means for closing the opening and closing valve of a flow passage when said detection value coincides with a memory value. CONSTITUTION:When a signal Se informing the completion of treatment is inputted to a microcomputer 10, the microcomputer 10 controls a solenoid valve 6 so as to bring the same to an open state. By this operation, for example, N2 gas is introduced into a vacuum container 1. The microcomputer 10 introduces the measured value Pa of a pressure sensor 8 in predetermined timing through an A/D converter 9 and successively compares the measured value Pa and the value PM stored in an internal memory in a process (25) and, at the point of time when both values coincide, brings the solenoid valve 6 to a closed state. |
