34
1. In the menu for CAN input 1...10, press the button
.
2. The conductivity electrode LRG 16-40 can be
calibrated on this screen.
3. When the compensation is switched OFF the
absolute conductivity is indicated.
4. Autoscan:
For this method a characteristic conductivity/
temperature curve of the plant (Auto curve)
is used for temperature compensation. How-
ever, a characteristic Auto curve must be
recorded first.
To do this, press the Autoscan button to start
recording the curve.
Now increase the steam boiler to the highest
operating pressure.
During the heating process, the temperature and conductivity values are recorded at every 10 °C
above 100 °C. After 25 values have been recorded or if “Compensation Off” is selected, the re-
cording is ended and the auto curve is saved.
The TK (AUTO) process is suitable for steam boilers operating with variable pressure.
5. Auto active:
When “Auto active” is selected, compensation is carried out according to the curve indicated by
“Autoscan”.
6. Standard curve:
Since conductivity is not a linear function of temperature over a larger temperature range, various
conditioning agents and different basic conductivities were used in order to ascertain empirical
conductivity/temperature curves. These curves are stored as standard curves and can be used for
temperature compensation. TK (NORM) is suitable for steam boilers operating with variable pres-
sure, which means that the boiler does not have a fixed working pressure (e.g. low load 10 bar,
full load 15 bar).
7. Linear:
To ensure that the readings are based on 25 °C, set the TK value to between 1.6 and 3.0 %/°C
(default is 2.1 %/°C). This setting permits the linear temperature compensation of the measured
value over the whole measuring range. This method is usually applied for steam boilers operat-
ing at a constant service pressure. After the TK is set and the service pressure is reached, use a
calibrated conductivity meter to measure the conductivity of the boiler water and compare the
reading with the indicated conductivity value. If the reading differs from the indicated conductivity,
change the TK setting until they tally.
8. Cell constant:
The cell constant is a geometric quantity characteristic of the conductivity electrode and is taken
into account when calculating the conductivity. However, this constant may change during opera-
tion, e.g. due to dirt deposits accumulated on the measuring electrode.
If a reference measurement yields a result that differs from the indicated conductivity value, check
the temperature compensation first. Only if the temperature coefficient setting is no longer suffi-
cient for a correct compensation should you modify the cell constant. In this case, change the cell
constant until the reading and the indicated conductivity match.
CAN 1...10 input LRG 1x4x calibration
Menus of Inputs/Outputs
continued
Summary of Contents for SPECTORcontrol
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