| 摘要 |
PURPOSE:To attain continuous discharge or supply of a fluid by using an inversely proportional value from H to L level or vice versa of a process fluid as an operation signal so as to regulate the flow and holding the fluid level to a point between the H and L. CONSTITUTION:The level LV of the fluid 2 at automatic operation has a 3-state such as over H, below L and between H and L, the 1st-3rd basic control means are provided depending on the 3-state. When the level LV is over H level, a setting data A1 of a data storage device 803 is used to increment or decrement an operation signal i0 by A1 each at each prescribed time in the 1st means. When the level LV is below L level, a setting data A3 of the data storage device 803 is used to decrement or increment the signal i0 by A3 each in the 2nd means so as to decreae the discharge or increase the supply with a prescribed gradient. When the level LV is between H and L, the operation signal i0 just before the level LV enters this range is controlled to be kept in this case in the 3rd means. |
