Owner manual

10
TWO-POINT CALIBRATIONTWO-POINT CALIBRATION
TWO-POINT CALIBRATIONTWO-POINT CALIBRATION
TWO-POINT CALIBRATION
For most applications it is recommended that pH 7.01 or 6.86 buffers be
used as the first calibration point and pH 3.00 (for acidic samples) or pH
9.18/10.01 (for alkaline samples) as the second calibration point.
Note: The pH 12.45 buffer is not for general measurement; use only if
the sample is very alkaline to avoid sodium error.
Submerse the pH electrode and the temperature probe approximately
3 cm (1¼”) into a buffer solution and stir gently. The temperature
probe should be close to the pH electrode.
Press the CAL key. “CAL” and “pH” tags will be on, and the
CLEAR CAL if new electrode” tag will blink.
Press the CLR key if you are using a new electrode or want to clear
the calibration history. The instrument will display the “donE
message for a few seconds.
Press the CAL key, or wait a few seconds to continue.
It is very important to clear the calibration history when a new electrode
is used because all error and warning messages that appear during
calibration depend on the calibration history.
Note: The “CLEAR CAL if new electrode” will only appear if the
instrument has been previously calibrated.
The “CAL”, “pH” and “BUFFER” tags will appear and the
7.01” buffer will be displayed on the secondary LCD.
Press the ARROW keys to select a different buffer value, if
necessary.
The “ ” tag will blink until the reading has stabilized.
CLEAR CAL if new electrode
pH
CAL