Swann AMU pH-Redox Operator's Manual page 71

AMU pH-Redox
Program List and Explanations
5.2.1.40
5.2.1.40.10
5.2.1.40.20
5.2.1.40.11
5.2.1.40.21
5.2.1.40.12
5.2.1.40.22
As control
output
A-96.250.441 / 060619
Scaling: Enter beginning and end point (Range low & high) of the
linear or logarithmic scale. In addition, the midpoint for the bilinear
scale.
Parameter Meas. Value:
pH sensor
Range low: -3 pH to +15 pH
Range high: -3 pH to +15 pH
Parameter Temperature:
Range low: -25 to +270 °C
Range high: -25 to +270 °C
Parameter Sample flow:
Range low: 0–200 l/h
Range high: 0–200 l/h
Signal outputs can be used for driving control units. We distinguish
different kinds of controls:
 P-controller: The controller action is proportional to the devia-
tion from the setpoint. The controller is characterized by the
P-Band. In the steady-state, the setpoint will never be
reached. The deviation is called steady-state error.
Parameters: setpoint, P-Band
 PI-controller: The combination of a P-controller with an
I-controller will minimize the steady-state error. If the reset
time is set to zero, the I-controller is switched off.
Parameters: setpoint, P-Band, reset time.
 PD-controller: The combination of a P-controller with a
D-controller will minimize the response time to a fast change
of the process value. If the derivative time is set to zero, the
D-controller is switched off.
Parameters: setpoint, P-Band, derivative time.
 PID-controller: The combination of a P-, an I - and a D-con-
troller allows a proper control of the process.
Parameters: setpoint, P-Band, reset time, derivative time.
Ziegler-Nichols method for the optimization of a PID controller:
Parameters: Setpoint, P-Band, Reset time, Derivative time
Redox sensor
-500 mV to +1500 mV
-500 mV to +1500 mV
69