Metrohm 840 PC Control 5.0 / Touch Control - Manual (Page 279)

4 Parameters
PC Control / Touch Control
267
Note!
Make sure that the sensor to be calibrated has been selected under
Edit command/Sensor. This is the only way to ensure that the cali-
bration data for this sensor is stored in the correct place under Sys-
tem/Sensors.
Sequence of the electrode test
Note!
In order to obtain realistic response times the electrode should be
immersed in each buffer at about the same time as the measurement
is started and it should be positioned directly above the stirrer which
has already been switched on.
Start the
calibration com-
mand
Measure or enter
the calibration tem-
perature
If a temperature sensor is connected then the
temperature will be measured. Otherwise a query
will appear and the temperature must be entered
manually.
Immerse electrode
into buffer pH 9
Confirm the displayed message with [OK].
Measure buffer
pH 9
The stirrer is switched on.
The potential of buffer pH 9 is measured; at first
3 min with stirring, then 1 min without stirring.
Immerse electrode
into buffer pH 4
Confirm the displayed message with [OK].
Measure buffer
pH 4
The stirrer is switched on.
The potential of buffer pH 4 is measured; at first
3 min with stirring, then 1 min without stirring.
Immerse electrode
into buffer pH 7
Confirm the displayed message with [OK].
Measure buffer
pH 7
The stirrer is switched on.
The potential of buffer pH 7 is measured; at first
3 min with stirring, then 1 min without stirring.
Calculate calibra-
tion data
The rating of the electrode is ascertained. The
calibration data will be added to the sensor data
for the particular sensor.