Burkert 8228 ELEMENT - Choosing the Type of Temperature Compensation

52
Operating and commissioning
Type 8228
9.11.11 Choosing the type of temperature compensation
See chap. 9.9 to access the Parameters menu.
This menu is used to deactivate the temperature compensation (choice “none”) or choose the type of temperature
compensation to determine the conductivity of the fluid:
• according to a linear percentage (choice “linear”, see "Linear temperature compensation (choice “Linear”)",
page 52).
• or according to a predefined curve (choix "NaCl", "NaOH", "HNO
3
" or "H
2
SO
4
").
The compensation curve H
2
SO
4
applies to a fluid temperature range of 5-55 °C and a concentration of 20,0%:
The compensation curves for NaOH, HNO
3
and NaCI apply to a fluid temperature range of 10-80°C and for
the following concentrations:
- NaCl: 0,2 %
- NaOH: 1,0 %
- HNO
3
: 1,0 %
• or according to a curve defined especially for your process (choice “Special”) using the “Teach special”
function in the “Calibration - Sensor” menu, “Probe” function (see chap. 9.12.4).
If the choice "Special" is set for this function:
• and the compensation curve has not been determined (see chap. 9.12.4), the measurements of the
conductivity are not compensated in temperature.
• If the compensation curve has been determined (see chap. 9.12.4), it is not uploaded with the
function UPLOAD (see chap. 9.11.1).
Param
This is
when the
device is be-
ing parame-
tered............
....................
This is
when the
device is be-
ing parame-
tered............
....................
Sensor
Special
NaCl
NaOH
Linear:0.000%
NoneComp.:
HNO3
H2SO4:
INPUT
Linear temperature compensation (choice “Linear”)
The linear temperature compensation may be sufficiently precise for your process whenever the temperature of
your process is always > 0°C. Enter a compensation value (average compensation coefficient alpha) between
0.00 and 10.00 %/°C.
Use the following curve and equation to calculate the average value of the compensation coefficient a according
to a temperature range DT and the associated conductivity range Dc:
χ
χ
25
25
T [°C]
∆χ
∆T
T
χ
T
α =
χ
25
∆χ
∆T
x
1
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