Bio-Rad BioLogic DuoFlow™ pH Monitor - Manual (Page 4)

Life Science
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00-000 0000 Sig 0101 Bulletin 0000 US/EG Rev A
Bio-Rad
Laboratories, Inc.
Electrode Cleaning
A dirty pH electrode can lead to erroneous pH readings and shorten the lifetime of the electrode. Most contami-
nant’s will be either proteins that have adsorbed onto the glass membrane or buffer and salt crystals that have
blocked the pH probe pores.
Removal of protein deposits: Immerse the electrode in a 1% solution of proteases, such as trypsin or pepsin, in
0.1M HCl for no more than 5 minutes. Rinse with deionized water to remove all traces of HCl.
Removal of salt deposits: Immerse the electrode in 0.1M HCl for 5 minutes followed by 0.1M NaOH for 5 minutes
and then 0.1M HCl for 5 minutes. Rinse the electrode with deionized water to remove all traces of HCl.
Storing Your pH Electrode Between Uses
When pH readings are made infrequently (i.e., several days or weeks apart), the electrode should be stored in its
plastic bulb filled with electrode storage solution (available from VWR or Orion) or pH 4 buffer in 3.5 M potassium
chloride.
Do Not Allow the Electrode to Dry Out.
Trouble Shooting
Symptom Possible Cause Possible Solution
Noisy or unstable Readings Air bubble on membrane Remove air bubble
Drift Solution temperature is changing Allow all solutions to come to thermal equilibrium.
Leakage around pH probe Loose nut Tighten pH electrode nut
Leakage around pH probe Missing or damaged o-rings Replace o-rings
Leakage around fittings Loose fitting Tighten fitting
Leakage around fittings Cracked or loose ferrule Replace fitting
Technical Assistance
For additional help, contact your local Bio-Rad representative. In the United States, call Chromatography
Technical Support at 1-800-4BIORAD.
Ordering Information
760-2040 DuoFlow pH Monitor
760-2042 pH Electrode
760-2044 Flow Cell
750-0502 Signal Import Module
910-1828 o-ring, pH flow cell, size 2-009
910-3014 o-ring, pH electrode, size 2-018
760-2046 BioLogic pH Monitor tubing kit – for connection between Conductivity flow cell and pH flow cell inlet
includes
1 x 28 cm 1/16” OD x 0.02” ID orange PEEK, rated to 5000 psi
1 x 28 cm 1/16” OD x 0.03” ID green PEEK, rated to 3000 psi
4106525 Rev B