Error Messages During Calibration; Determining The Relative Time Constant With A Calculation - JUMO 202710/30 Operating Manual

7.2.3 Error messages during calibration

7.3

Determining the relative time constant with a calculation

Example
Once a stable value has been determined, the device will save the correction
factor and return to measurement mode, or it will display an error message if
necessary.
The resulting relative cell constant is briefly shown and can always be viewed
in the "SEt ConF" menu under the parameter "CELL Corr".
Display Meaning
CAL.-Err.1 Relative cell constant too large Determined
CAL.-Err.2 Relative cell constant too small Determined
CAL.-Err.3 Solution in incorrect range
CAL.-Err.4 Incorrect temperature
As an alternative to calibrating the relative time constant, this can also be
determined using a calculation and manually entered on the device using the
parameter "CELL Corr". A reference solution is also required for this purpose.
The calculation is carried out as stated in the following example.
KCl solution with the concentration 0.1 M: 1413 µS/cm at 25°C
(At other temperatures, switch off the temperature compensation (t.Cor = oFF)
and use the conductivity value that corresponds to the temperature!)
Assumption: Conductivity
("CELL Corr") out of 1.000
Conductivity of the solution at 25 °C (conductivity
Relative cell constant k =
In this example, the parameter "CELL Corr" must be set to the value "0.942".
The main display of the device shows the measured actual
value (e.g. 1407 µS/cm) and the subsidiary display shows
"CAL." with a symbol rotating around the last digit.
= 1500 µS × cm
display
7 Calibration
Explanation
relative
must not be > 1.2
relative
must not be < 0.8
Incorrect reference
beyond the tolerance
Reference solution outside the per-
missible temperature (0.0 to 34.0 °C,
or 0.0 to 27.0 °C with reference solu-
tion 111.8 mS/cm)
-1
at set relative cell constant
) = 1413 µS × cm
target
cell constant
cell constant
solution, way
-1
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