PASCO PS-2108 Dissolved Oxygen Sensor - Manual (Page 11)

Model No. PS-2108 Dissolved Oxygen Sensor
7 ®
Maintenance
Changing the Electrolyte solution
The electrolyte solution (probe filling solution) should be
periodically replaced and the silver electrode cleaned to maintain
optimal performance of the probe. If the probe is not performing
optimally, replace the electrolyte solution as follows:
1. Unscrew the end of the probe by turning it to the left, and
remove the cartridge housing (Figure 5).
Always hold the probe below the stainless steel band when
unscrewing the cartridge housing or otherwise applying torque
to the end of the probe.
2. Rinse the electrode with tap water (or deionized water in areas
with hard tap water) and rub it dry with a paper towel, removing
loose silver oxide (Ag
2
O) from the anode.
3. Rinse and air dry the cartridge housing.
4. Pull about 10 ml of the Polarographic solution into the syringe,
being careful not to introduce air bubbles.
5. Place the tip of the syringe very close to, but not touching the
membrane, and slowly fill the membrane cartridge and cartridge
housing to approximately 5 mm from the top of the housing.
Note: Tap the cartridge housing while filling to avoid introducing air bubbles.
6. Holding the probe in a vertical position, slip the cartridge housing
over the electrode and turn to the right to tighten (Figure 6).
7. Dry with a paper towel or tissue.
Replacing the Membrane
If the silicon membrane becomes torn or otherwise damaged, replace it
as follows:
1. Follow steps 1 through 3 under "Changing the Electrolyte Solution"
above.
Figure 5
Removing the cartridge
housing and filling with
electrolyte.
Figure 6
Replacing the cartridge
housing.