Polarographic dissolved oxygen sensors should be stored in a clean, dry environment prior to usage. Some models, such as the OxyFerm, ship with a protective watering cap over the tip of the sensor. Other models, such as the OxyGold, ship with a yellow rubber cap. If the watering cap is used, it should be periodically inspected to ensure that liquid is present. Deionized water can be used if liquid needs to be added.
A look inside the packaging of a new OxyGold sensor shows the additional electrolyte used to refill the membrane cap. The sensor tip is protected during shipment by the yellow rubber cap which should be discarded prior to use.
Shelf Life & Short-Term Storage
Polarographic sensors have no shelf life restrictions, however they require electrolyte to function properly. For short-term storage (< 1 month) the sensor can be stored with electrolyte in the membrane cap and the watering cap installed. Keep the watering cap supplied with the sensor or contact Hamilton for spares.
Long Term Storage
For long term storage, (> 1 month) we recommend connecting the sensor to verify functionality. Upon power-up the sensor should provide an oxygen reading > 60% (Air-Sat) within several minutes. If the sensor is determined as functional, remove power, drain the electrolyte from the sensor cap, rinse the internal cathode assembly with deionized water and store the sensor dry. The electrolyte provided with the sensor packaging has a shelf life of 2 years. If the electrolyte has expired prior to initial usage contact Hamilton for replacement solution.
Polarographic sensor maintenance kits include the following:
- OxyFerm FDA Membrane Kit - Ref 237140
- OxyGold Membrane Kit - Ref 237135
- Traditional OxyFerm Membrane Kit (OptiFlow Caps) - Ref 237123
- OxyFerm CIP Membrane Kit - Ref 237126
- Procedure for Polarographic DO sensor cathode replacement.
- Time to upgrade from Polarographic to Optical DO Measurement? See the comparison here.
- Visit our main Dissolved Oxygen Knowledge Base Page to see all articles.