3.8 pH CALIBRATION - AUTOMATIC
Auto buffer recognition operates over the range of 0 to 100°C and will recognise 2.00, 4.00,7.00, 9.22 and
10.00pH. If calibration values other than 2.00, 4.00, 7.00, 9.22 and 10.00 are set the instrument will consider
this to be a manual buffer calibration.
NOTE: Rinse electrode(s) in deionised water between measurements.
Calibration is performed by selecting the pH mode and then moving the cursor to the CAL menu option and
pressing . The instrument will then show:
An icon will appear indicating the CAL 1 buffer value and the first part of the calibration. The buffer value(s)
can be changed at this point by entering the CAL BUFFERS... menu and setting new values by using the
numeric keys and pressing .
To calibrate the instrument select the CALIBRATE menu option using the arrow keys. The electrode(s)
should be placed into the first buffer solution and the reading allowed to stabilise (the endpoint symbol will be
displayed) prior to pressing the key. The display will then update to the standard buffer value, corrected
for temperature (actual temperature will be displayed).
The icon will then change to show the CAL 2 buffer value. If a one point calibration only is required select
the EXIT option using the arrow keys and pressing . The instrument will return to the pH mode.
If a two point calibration is required the electrode(s) should be rinsed and then placed into the second buffer
solution. Allow the reading to stabilise (the endpoint symbol will be displayed) prior to pressing the key.
The display will then update to the standard buffer value, corrected for temperature (actual temperature will
be displayed).
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