Calibrating Instrument - TESTO 206 Instruction Manual

28 5. Operation

5.4 Calibrating instrument

Please also adhere to the instructions supplied with the buffer
solution (Testo buffer: see label).
During calibration it is important, that the glass probe does not
touch the synthetic material of the bottle. Preferably do not
leave the instrument in the bottle, as variations in calibrations
of up to ± 0.4 pH can arise.
The instrument is switched on and is in the measurement mode.
1 Open calibration mode:
- testo 206-pH3 with pH probe without temperature sensor: The
set temperature value for manual temperature compensation
is displayed for 2s. The value must correspond to the temper-
ature of the buffer solution.
- Calibration point (4, 7 or 10) is shown and CAL flashes.
2 Skip calibration point:
-or-
Immerse probe in the buffer solution and start calibration:
.
CAL
- The instrument waites for a stable reading : AUTO flashes.
- If a stable reading is available (change less than 0.02pH in
20s), the calibration point calibrates and the instrument
changes to the next calibration point (if available) or to the
gradient and offset value display.
3 Repeat Step 2 for additional calibration points.
- Once calibration is complete, the amount of the gradient and
offset value is shown. If the amount of the gradient value is less
than 50mV / pH or the amount of the offset value is greater
than 60mV, the pH electrode is spent and must be replaced.
4 Return to measurement view:
MODE
Carry out calibration manually:
CAL
.
.
.
CAL
.
CAL