Kc = 2.04, Ti = 22 minutes
66
Process Variable
Controller Output
100
64
90
62
80
60
58
56
54
52
50
70
60
50
40
30
20
Controller Output
Process Variable
48
10
46
0
–10
0
10
20
30
40
50
60
70
Time, minutes
Figure 9.2 Response with 0.5 times optimum gain.
Kc = 1.02, Ti = 22 minutes
Process Variable
Controller Output
Process Variable
Controller Output
66
64
62
60
58
56
54
52
50
48
46
100
90
80
70
60
50
40
30
20
10
0
–10
0
10
20
30
40
50
60
70
Time, minutes
Figure 9.3 Response with 0.25 times optimum gain.
Closed-Loop Tuning of Controllers ◾  91