Manual OPTISENS CAC 050 / IAC 050
17
OPTISENS CAC 050 / IAC 050
4.4.1
Calibration of the temperature measurement
When using a 2-wire connection for the temperature sensor, please check the temperature measurement in
the beginning. If the displayed temperature differs from the real temperature, enter the deviation as
correction in the basic settings. This correction will be added to all temperature measurements. If your
calibration was correct, the temperature displayed is now equal to the real temperature.
4.4.2
Temperature coefficient
The temperature influence on the conductivity depends upon the composition of the solution and often
cannot be expressed by a simple equation. Instead the temperature dependency is compensated using a
linear coefficient given as deviation in % per K.
For most applications a coefficient of 2.5%/K can be used to good results. For ultra-pure water better select
the non-linear compensation “pure water“.
5.
Adjustments of the controller
Main menu
.
.
Set points
.
Selection of ON/OFF, P or PI controller, adjustment of P ranges and I
functions for 2 set points.
.
Basic settings
Basic settings
.
.
Contr. settings
Turn-on delay
Adjustment of frequencies and pulse/pause
times, hysteresis, direction of the control
action, delay
For any type of controller you have to enter one or two set points, and you have to tell the device whether
these set points are reached by increasing or decreasing the measured value.
You can choose between three different controller versions:
ON/OFF controller
The ON/OFF controller switches ON if the measured value exceeds the set point and OFF if it drops back
below it or vice versa. Dosage is always carried out with 100% (ON) or 0% (OFF). The parameter for an
ON/OFF controller is the hysteresis.
P controller
The P controller or proportional controller reduces the dosage in the vicinity of the set point proportional to
the control deviation. This is easily achieved if the analog output is used as steady control output. If the
relays are used, the proportional reduction is achieved by either reducing the switch frequency (Impulse-
frequency controller) or reducing the time within a given period of time in which the relay is ON (pulse-pause
controller). The parameters for a P controller are the P range and the impulse- frequency or the pulse+
pause time and the minimum pulse. (See Point 5.3)
PI controller
The PI controller is a P controller with an additional I function. Adjustments and parameters are the same as
for a P controller. Additionally the integral action time has to be adjusted which determines the I function.
The I function eliminates the P controller’s disadvantage of a remaining steady-state deviation.
