Grundfos Conex DIA-2, Installation And Operating Instructions Manual

Page: 48 / 612

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48
Error messages during the reading in of the
voltage signal of the pH electrode
The calibration may be aborted in the following
cases:
•
If the electrode is faulty or a wrong buffer has
been used.
– The message "fault of electrode/buffer" is
displayed.
• If the electrode does not reach a stable
measuring signal in 120 seconds.
– The message "calibration time exceeded" is
displayed.
• If the result of the plausibility testing of the pH
calibration data is upward/downward violation of
the slope range of -50 to -62 mV/pH.
– The message "slope error" is displayed.
• Downward/upward violation of the
precision/exactness range from -60 to +60 mV.
– The message "error asym. pot." is indicated.
The calibration process will be aborted in all four
cases.
•
Press [OK] to return to the "calibration" menu
automatically.
If the process is aborted, the old calibration date will
not be overwritten!
Manual temperature compensation
With deactivated temperature measurement, the water
temperature for compensation should be entered
manually after calibration. The default value is 25 °C.
1. Determine the water temperature with a
thermometer.
2. Press [Cal] to switch to the calibration function.
Select the line "pH", and press [OK] to switch to
the "pH" calibration menu.
3. Select "manual temp.", and press [OK] to switch
to the corresponding menu.
4. Enter the water temperature.
– The water temperature is shown in °C (Celsius)
or in °F (Fahrenheit), as selected in the "setup"
menu "measuring ranges".
5. Press [OK] to return to the "calibration" menu
automatically.
Cal. cycle
• Following selection of "cal. cycle" in the
"measured value" menu, a countdown function is
started which triggers the alarm signal "calibrate
sensor" following expiry of a defined time interval
of 1-100 days.
Cal result
• The result of the current (last) calibration can be
displayed at any time using the "cal result" menu
item.
manual temp.
25 °C