| 摘要 |
PROBLEM TO BE SOLVED: To manage the unsoundness of the flow rate control system of a controller under a higher degree of certainty.SOLUTION: A management index arithmetic unit 53 is provided in a positioner 5. The management index arithmetic unit 53 acquires an opening indication value θ_SP from a controller 4 and the actual opening θ_PV of a valve 2 detected by an opening detection unit 52 on a prescribed sampling cycle Δt, and finds, from the opening indication value θ_SP and actual opening θ_PV of the valve 2 within a prescribed period T that are acquired on sampling cycle Δt, a management index Aj(Aj=ΣΔθ_SPi÷ΣΔθ_PVi) as an index indicating the possibility of unsoundness of the flow rate control system of the controller 4. The management index Aj is sent to a host system 6, the reliability of the management index Aj is evaluated by a management index reliability evaluation unit 63, and a different kind of alarm is issued in accordance with the evaluation result.SELECTED DRAWING: Figure 2 |
