Do Probe Maintenance - Hanna Instruments Edge Instruction Manual

The platinum cathode (DO Probe Diagram, page 67) should always be bright
and untarnished. If it is tarnished or stained, the cathode should be cleaned.
You can use a clean lint-free cardboard or cloth. Rub the cathode very
gently side to side 4-5 times. This will be enough to polish and remove any
stains without damaging the platinum tip. Afterwards, rinse the probe with
deionized or distilled water and install a new membrane cap using fresh
electrolyte and follow DO Probe Preparation page 65.
Important
In order to have accurate and stable measurements, it is important that the
membrane surface is in perfect condition. This semi-permeable membrane
isolates the sensor elements from the environment but allows oxygen to
enter. If any dirt is observed on the membrane, rinse carefully with distilled
or deionized water. If imperfections still exist, or any damage is evident (such
as wrinkles or tears), the membrane should be replaced. Make sure that the
O-Ring sits properly in the membrane cap.
DO Probe
Maintenance
Maintenance
81