Xylem ProLab 4000 - Manual (Page 83)

ProLab 4000 pH
83 ba75646e03 12/2012
7.3.2 Carrying out a calibration procedure (example: VariCal)
Make sure the Calibration / pH calibration type / VariCal calibration type
is marked (see page 73).
Single-point calibration Use any buffer solution for this rapid method.
The calibration will be the more exact the nearer the pH value of the
buffer solution is to that of the test sample.
Two-point calibration Use two buffer solutions for this procedure:
 first buffer solution: pH 7.000 ± 0.500
 any other buffer solution
To carry out the calibration procedure, the pH calibration type VariCal
must be set in the sensor menu (see page 87).
1 Perform the preparatory activities (see page 78).
2 Start the calibration with .
The pHX calibration window opens.
3 When measuring without temperature sensor:
 Measure the temperature of the standard solution using a
thermometer.
 Open the setting window for the temperature value with
[Man. temp.].
 Enter the temperature and confirm with [OK].
4 Thoroughly rinse the electrode with distilled water.
5 Immerse the electrode in buffer solution 1 (pH 7.000 ± 0.500).
6 Start the measurement with [Continue].
The measured value is checked for stability (Stability control).