wtw pH/Cond 3320 - Calibration

Ion concentration pH/Cond 3320
40 ba77054e03 03/2018
7.2 Calibration
7.2.1 Why calibrate?
Ion-selective electrodes age and are temperature-dependent. This changes
the slope. As a result, an inexact measured value is displayed. Calibration
determines the calibration line of the electrode and stores this value in the
meter.
Thus, you should calibrate before each measurement (if possible), and at
regular intervals.
7.2.2 When to calibrate?
 Before any measurement if possible
 After connecting another ISE electrode
 When the sensor symbol flashes, e.g. after a voltage interruption (empty
batteries)
7.2.3 Calibration (ISE Cal)
ISE Cal is the conventional two-point to seven-point calibration procedure
that uses 2 to 7 freely selectable standard solutions. The concentration
expected in the measurement determines the concentration of the calibration
standards.
2. When measuring without temperature sensor:
– Temper the test sample, or measure the current temperature.
1. Connect the ISE electrode to the meter.
The pH/U/ISE measuring window is displayed.
2. Keep the standard solutions ready.
3. When measuring without temperature sensor:
– Temper the test sample, or measure the current temperature.
4. In the measured value display, select the ISE measuring window with
< >< > and <M>.
5. If necessary, change the unit of the measurement result and calibration
standards in the ISE setup/Unit menu.
6. Start the calibration with <CAL>.
The calibration display appears.