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2665 JL Bleiswijk, The Netherlands
T. 31 (0) 10 522 43 73
F. 31 (0) 10 521 19 41
E-mail: [email protected]
Website: www.tamson.com
VAT: NL 80 66 34 984 B01
Bank account no.: Rabobank 16 01 00 046
Chamber of commerce 27 16 95 41
IBAN Code: NL95 RABO 0160100046
Tamson Instruments bv
tv2000-4000mkII-4000DC-man.doc Rev. 2.3 UK 9-15
7.4
Manual tuning
The parameters for the PID control can be changed
manually.
The control of the PID parameters allow setting of the I
and D values to zero. The bath will then function as a
proportional sys
tem. The “P” parameter can than be
varied to an optimal value by trial and error. A higher P
will stabilize the system when I and D are off. The PID
parameters can also be determined with the use of the
Ziegler Nichols method described below.
The PID parameters can also be determined with the
use of the Ziegler Nichols method described below. With
the process at its normal process value.
Set the integral time “Ti” and the derivative Time “Td” to
off.
Ignore the fact that the temperature may not settle
precisely at the set point. If the temperature is stable,
reduce the proportional band Pb so that the temperature
just starts to oscillate. If the temperature is already
oscillating, increase the proportional band until it begins
oscillating. Allow enough time between each adjustment
for the loop to stabilize. Make a note of the proportional
band value “B” and the period of oscillation “T” Set the
Pb, Ti and Td parameter values according to the
calculations given in the table below:
Type of control
Proportional band
Integral time "
ti
"
Derivative Time "
td
"
Proportional only
2xB
Off
Off
P + I control
2,2xB
0,8xT
Off
P + I + D control
1,7xB
0,5xT
0,12xT