YOKOGAWA UT Advanced UT32A User Manual page 78

Manual PID Tuning Procedure
IM 05P01D31-01EN
(1) In principle, auto-tuning must be used.
(2) Tune PID parameters in the order of P, I, and D. Adjust a numeric slowly by
observing the result, and keep notes of what the progress is.
(3) Gradually reduce P from a larger value. When the PV value begins to oscillate, stop
tuning and increase the value somewhat.
(4) Also gradually reduce I from a larger value. When the PV value begins to oscillate (with
long period), stop tuning and increase the value somewhat.
(5) Gradually increase D from a smaller value. When the PV value begins to oscillate (with
short period), stop tuning and lower the value slightly.
Reference Values for Manual Tuning of Temperature, Pressure, and Flow Rate
Setting range
(reference)
P 100 to 300%
Pressure I 5 to 30 s
D
P 100 to 240%
Flow rate I 8 to 30 s
D
P 1 to 20%
Temperature
(electric I 180 to 600 s
furnace)
D 1/4 to 1/6 of I
Initial value for tuning (reference)
200%
OFF
150%
OFF
240 s
6.4 Adjusting PID Manually
15 s
OFF
20 s
OFF
5%
60 s
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