Stratos Multi E461N
70
6.8.3 Temperature Compensation of Process Medium
Note:
If temperature compensation of the process medium is enabled, “TC” is shown on the display in
measuring mode.
The following are available for temperature compensation:
• Linear with input of a temperature coefficient TC
• Ultrapure water
• Table
Linear Temperature Compensation of Process Medium
If the medium’s pH value changes in linear fashion with the temperature, the temperature coefficient
TC can be determined for temperature compensation in %/K as follows:
TC = (pH
25
– pH
T
) • 100 / (25 °C – T) [%/K]
TC
Temperature coefficient [%/K]
pH
25
pH value at 25 °C
pH
T
pH value at measuring temperature T
T
Measuring temperature [°C]
Table
When using process media with a known pH value temperature response, the pH output value can be
corrected using a table. The percentage deviation from the measured value in % can be entered for
temperatures between 0 and 95 °C in steps of 5 °C. The pH output value is then corrected by the corre-
sponding percentage deviation from the measured value in %, depending on the measuring tempera-
ture. Table values are linearly interpolated. If the temperature falls below or exceeds the specified
value (< 0 °C or > 95 °C), the last value in the table is used for calculation.
The table must be completed with the following values in steps of 5 °C:
((pH
25
/ pH
T
) – 1) • 100 [%]
pH
25
pH value at 25 °C
pH
T
pH value at measuring temperature T
Settings can be changed in the
TC Process Medium
submenu:
Parameter Setting
[I] [II] … pH
TC Process Medium
Note:
If the delta function and TC correction are enabled at the same time, the TC correction is carried
out first and the delta value is then deducted.
6.8.4 Delta Function
Note:
If the delta function is enabled, “∆” is shown on the display in measuring mode.
If a delta value is specified, the measuring system calculates the difference
output value = measured value – delta value
The delta value can be set using the “+” or “-” signs. If using a negative sign, the delta value is added to
the measured value.
The delta value is adjusted in the
Delta Function
submenu:
Parameter Setting
[I] [II] [Sensor]
Delta Function
All outputs are controlled by the output value; the displays show the output value.
Note:
If the delta function and TC correction are enabled at the same time, the TC correction is carried
out first and the delta value is then deducted.
