Thermo Products 9678BNWP manual Assistance Warranty, Checking Electrode Operation

Checking Electrode Operation

Checking the electrode is necessary only when there is evidence of malfunction that cannot be traced to other causes. Fill the electrode with Cat. No. 900011 filling solution for this testing procedure.

1.Prepare solution A (0.1 M potassium ferrocyanide and 0.05 M potassium ferricyanide): weigh out 4.22 g reagent-grade

K4Fe(CN)6•3H20) and 1.65 g reagent-grade K3Fe(CN)6. Place in a 100 mL volumetric flask. Add about 50 mL distilled water and swirl to dissolve solids. Dilute to volume with distilled water.

2.Prepare solution B (0.01 M potassium ferrocyanide, 0.05 M potassium ferricyanide and 0.36 M potassium fluoride):

weigh out 0.42 g reagent-grade K4Fe(CN)6•3H20), 1.65 g reagent-grade K3Fe(CN)6 and 3.39 g reagent-grade KF•2H2O. Place in a 100 mL volumetric flask. Add 50 mL distilled water and swirl to dissolve solids. Dilute to volume with distilled water.

3.Transfer solution A to a 150 mL beaker. Place the electrode in the solution and wait until the reading stabilizes. The potential should be about 234 mV.

4.Transfer solution B to a 150 mL beaker. Rinse the electrode and then place it in the solution and wait until the reading stabilizes. The potential should be about 66 mV greater in solution B than in solution A.

Assistance

After troubleshooting all components of your measurement system, contact Technical Support. Within the United States call 1.800.225.1480 and outside the United States call 978.232.6000 or fax 978.232.6031. In Europe, the Middle East and Africa, contact your local authorized dealer. For the most current contact information, visit www.thermo.com/water.

Warranty

For the most current warranty information, visit www.thermo.com/water.

Redox/ORP Electrode User Guide 19