Bio-Rad BioLogic DuoFlow™ pH Monitor - Manual (Page 3)

Figure 3. pH Monitor connected via a DuoFlow Maximizer.
Programming your pH Monitor
See the DuoFlow instruction manual for instructions on programming your pH Monitor.
Calibrating your pH Monitor
The frequency of calibration is a function of the electrode and the solutions it is exposed to. The pH electrode calibration
should be checked daily to assure that its accuracy remains within the range required for your application. Calibration is
done with two standard solutions that span the pH range over which your experiment will be run (for example pH 7 and 4
or pH 7 and 10). Following is a calibration procedure:
Calibration procedure
1.
Remove the electrode from the flow cell.
2. Rinse the electrode with deionized water.
3.
Place the electrode in the first calibration buffer.
4. From the Utilities drop down menu in the DuoFlow software, select “pH probe calibration”.
5. Enter the temperature from the pH probe calibration screen and reference pH for your first buffer. Press Set.
6. When the pH reading has stabilized, press Okay.
7. Remove the electrode from the buffer and rinse with deionized water.
8. Place the electrode in the second calibration buffer.
9. Enter the reference pH for the second buffer. Press set.
10. When the pH reading has stabilized, press Okay.
Hint: Keep calibration and elution buffers at the same temperature. This will eliminate the need to correct values for
temperature effects. Allow sufficient time for the pH reading to stabilize. In general, buffers at low concentrations
take longer to stabilize. Do not expose the electrode to extreme pH solutions for prolonged periods of time. Doing so
will severely shorten the lifespan of the electrode.
Maintenance of your pH Monitor
All pH electrodes age with time. Aging is characterized by slower speed of response or drifting. Your electrode
should typically have specific voltage readings at different pH’s as specified in the chart below.
Standard solution Voltage
pH 7 0 ± 30 mV
pH 10 -171 ± 30 mV
If your electrode differs significantly from the above reading, clean the electrode according to the following direc-
tions. If performance is not restored, then the electrode should be replaced.
3
WORKSTATION
MAXIMIZER
pH ELECTRODE
pH MONITOR
pH FLOW CELL