WDT Granudos 10 Touch, Инструкции по эксплуатации и монтажу

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GRANUDOS Touch, control unit
Index: 02 Date modified: 11/06/2019 OI No.: BA SW 010-02 Granudos Touch-Steuereinheit EN SCHW 8.docx Page 26 of 43
Main menu 
Calibration (Optional for design with buffer tank)
ph (2-point)
Two-point calibration of the pH electrode
pH (phenolred)
One-point calibration of pH electrode
The calibrations are graphically guided and are accompanied by a help
text. Follow the menu prompts. Use the OK button to acknowledge
the completed steps.
Main Menu

Calibration

pH (2-point)
Perform calibration in accordance with the instructions.
Once the pH calibration has been completed, the measuring results for
the offset voltage and conductance voltage are displayed and an
evaluation of the electrodes carried out. In case of minor deviations,
the calibration is adopted immediately. In case of "medium" deviations,
a cleaning notice is displayed. In case of major deviations, the exchange
of the pH electrode is suggested. If the exchange of the electrode does
not remedy the problem, the fault may be with the electrode cable or
the measuring amplifier.
pH7 = buffer solution for determining offset voltage.
The optimal offset voltage is at 0mV up to +/-30mV.
pH4 = second buffer solution for determining conductance voltage.
Slope (Inclination) mV/pH
The optimal slope voltage at 25°C is approx. 59mV/pH.
(pH7 – pH4 = 3pH x 59mV = 177mV)
Example: (mV(pH 4)= 187mV – mV(pH7)= 10mV) = 177mV ./. 3 pH
= 59 mV/pH
NOTICE!
Notice regarding evaluation of the electrodes
Cleaning notice
If the offset voltage is less than +/-41mV the voltage rating will appear yellow and the calibration will be terminated with a
cleaning notice.
If the conductance voltage is between 52mV/pH and 63mV/pH, the voltage rating will appear yellow and the calibration
will be terminated with a cleaning notice.
Error notice
If the offset voltage is greater than +/-61mV the voltage rating will appear red and the calibration will be rejected with an
error notice!
If the conductance voltage is less than 50mV/pH or greater than 65mV/pH, the voltage rating will appear red and the
calibration will be rejected with an error notice!
If the calibration is rejected with an error notice, the device continues the regulation using the values from the most recent
successful calibration.
It is necessary to investigate the cause of the failed calibration!