Bio-Rad ChromLab™ Software - Manual (Page 261)

pH Probe
Instrument Guide | 259
pH Probe
Symptom Possible Cause Possible Solution
The pH readings are
higher or lower than
expected. The pH probe might need to be
calibrated. Recalibrate the pH probe. In
ChromLab, select Tools >
Calibrate > pH. Complete the
calibration steps in the dialog
box.
The pH readings are
noisy or unstable. Air bubbles might be present in
the pH probe flow cell.  Flush the system to remove
air bubbles.
 Check the values for slope
and offset. If they are not
within specifications, replace
the pH probe.
The pH trace is drifting. The temperature of the solution
is changing. Allow all solutions to come to
thermal equilibrium.
Note: Ensure that the
instrument and all solutions
are equilibrated to the same
temperature.
The pH response is slow. The pH electrode is
contaminated or worn. Clean or replace the probe.