2018 年 52 巻 p. 9-12
The purpose of this study is to develop a control system of an arbitrary oxygen (O2) concentration with quick responses and high accurate control. The proportional control electromagnetic valve can change the flow rate from 0% to 100% (10l/min) with the step of 1.25%, that is, it can control the oxygen concentration of an experimental chamber with high accuracy. Additionally, the gas of 30% oxygen was used to recover quickly to the normal air condition. As the result, the average difference between target oxygen concentration and actual condition was ±0.35O2%, which was larger than that of the previous system. In addition, an undershoot and an overshoot of control often occurred near the target value. Since these errors are attributed to the non-optimal control program, it must be improved for high accurate oxygen concentration.