Thermo Products REDOX/ORP 9678BNWP - Manual (Page 21)

Redox/ORP Electrode User Guide
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
K
4
Fe(CN)
6
•3H
2
0) and 1.65 g reagent-grade K
3
Fe(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 K
4
Fe(CN)
6
•3H20), 1.65 g
reagent-grade K
3
Fe(CN)
6
and 3.39 g reagent-grade
KF•2H
2
O. 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.