Section 2
pH Calibration and Measurement
For accurate results, stir all buffers and samples. Always rinse elec
trodes and blot dry before transferring from one solution to another
to prevent contamination. Ensure that any electrode filling holes
are left uncovered during use.
Automatic Calibration & Temperature Compensation
0
Connect the pH electrode(s) and temperature probe and
switch on using the power ON/OFF switch on the back
panel.
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Select pl-I mode and clear any calibration data by pressing
the Clear key for 5 seconds.
0
Place the pH electrode(s) and the temperature probe in the
pH 7 buffer and wait for a stable reading. *Press the Enter
key. The fist calibration point will now be entered automati
cally at the correct value for the temperature of measure
ment. The Cal flag will be displayed.
0
Rinse, blot and place the pH electrode(s) and temperature
probe in the second buffer (4 or 10). Wait for a stable read
ing. *Press the Enter key. The second calibration point will
now be entered automatically at the coJ
T
ect value for the
temperature of measurement.
0
Rinse, blot and place pH electrode(s) and temperature probe
in the sample. Wait for a stable reading and record pH val
ue.
0
Temperature or m V measurements may be made at any time
by pressing the appropriate key.
Note: The display may beji-ozen at any time by pressing the HOLD
key if using the RE357 or the SEND key if using the RE357Tx with
no computer or printer connected. To release the display press the
key again.
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