JUMO 202710/30, Руководство по эксплуатации

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35
7 Calibration
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".
7.2.3 Error messages during calibration
7.3 Determining the relative time constant with a calculation
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.
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
display
= 1500 µS × cm
-1
at set relative cell constant
("CELL Corr") out of 1.000
Conductivity of the solution at 25 °C (conductivity
target
) = 1413 µS × cm
-1
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.
Display Meaning Explanation
CAL.-Err.1 Relative cell constant too large Determined relative cell constant
must not be > 1.2
CAL.-Err.2 Relative cell constant too small Determined relative cell constant
must not be < 0.8
CAL.-Err.3 Solution in incorrect range Incorrect reference solution, way
beyond the tolerance
CAL.-Err.4 Incorrect temperature 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)
Relative cell constant k =
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