3.2.3 pH Calibration using NIST standard buffers
1.
Pour a known pH buffer standard solution into a clean container, e.g. pH
6.86. Power on meter, and it will automatically enter the measurement
mode. Select the pH mode by pressing the
MODE
key if necessary.
2.
Dip both the pH electrode and temperature probes into the pH 6.86 buffer
solution. Swirl gently and wait for reading to stabilize (approx. 30 seconds
depending on the electrode condition).
3.
Press the
CAL
key to enter the pH calibration mode. “
CA
” will be displayed
momentarily and the display will flash with the current uncalibrated
reading.
4.
To abort or cancel the calibration without accepting the new value, press
the
CAL
key. The meter then reverts to the pH measurement mode
.
5.
To proceed with the calibration, allow the reading to stabilize. The meter
automatically recognizes pH 4.01, 6.86 or 9.18 buffers. Press the
ENTER
key to confirm the calibration and the LCD will display “
CO
” momentarily.
The meter will revert to the measurement mode.
6.
For a 2 or 3-point calibration, repeat step 3 with other pH buffer values of
4.01 and/or 9.18 for higher accuracy.
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