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6 Calibration of the pH combination electrode
6.7
Error messages of the pH calibration
NOTE!
After prior 2 point calibration, the slope for the entire measuring range is
displayed (SL.).
After prior 3 point calibration, the slope for the acidic range is displayed
first (SL. 1). After pressing the
key again, the slope for the alkaline range
(SL. 2) is displayed.
Display
Cause
Remedy
The neutral buffer is not admissible:
•
Combination electrode is defective Clean combination electrode, recalibrate.
If error reoccurs:
replace combination electrode
•
Wrong buffer solution
Always use neutral buffer as first solution (excep-
tion: 1 point calibration)
•
Buffer solution used up
Use new buffer solution
The slope is too low:
•
Combination electrode is defective
•
Buffer solution used up
Replace combination electrode
Use new buffer solution
The slope is too high:
•
Combination electrode is defective
•
Buffer solution used up
Replace combination electrode
Use new buffer solution
Wrong calibration temperature
Only carry out calibration between 0 and 60 °C
