Thermo Fisher Scientific ECDOTPII-S Submersible Galvanic Dissolved Oxygen Sensor - Manual (Page 3)

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MEMBRANE TYPE
Two types of membrane materials are offered for DO sensors, either PTFE or HDPE. Teflon offers excellent
durability and moderate speed of response. HDPE offers fast response but less mechanical strength. The
PTFE membrane also has less membrane permeability error with temperature as compared to HDPE.
Spare membranes are available is 5 or 25 counts, or in maintenance kits.
MOUNTING YOUR DO SENSOR
Submersion mounting of the sensor is recommended. To prevent air bubbles from becoming trapped on
the membrane and producing falsely high DO readings, it is recommended that the sensor be mounted
with the membrane pointing slightly upward (not horizontal) as shown in FIG. 2.
SENSOR RE-CONDITIONING
1. Unscrew the lower body from the upper body(FIG. 3)
2. Safely dispose of the electrolyte that is a special molarity, reagent grade Sodium Chloride
solution (salt water) as shown in FIG. 4
3. Using the Membrane Tool, unscrew the Membrane Lock in the lower body as shown in FIG. 5
4. Remove and dispose of the membrane and its O-Ring as show in FIG 6
5. Using a toothbrush, dishwashing powder and clean water, clean the cathode, anode, and plastic
between them. Rinse all components thoroughly. Household Ammonia may be used to clean
the silver anode overnight If Ammonium Hydroxide is used, expose it for no more than 3
minutes (it is very strong). See FIG. 7.
6. Install a new O-Ring into the lower body membrane cavity then a new membrane into the lower
body. Using the Membrane Tool, screw the Membrane Lock on top of the membrane as shown
in FIG. 8.
7. Inspect the membrane for wrinkles--replace if it is wrinkled.
8. Pour some water into the lower body and look for leakage around the membrane--replace it if
there is leakage. If no leakage, dispose of the water.