EIJKELKAMP 18.50.01 Bedienungsanleitung Seite 138

4. Using the installation tool, unscrew and remove the membrane lock from the membrane cap.
5. Remove the membrane and O-ring. Discard both.
6. Rinse the membrane cap and membrane lock in tap water.
7. Install a new O-ring inside the membrane cap.
8. Install a new membrane. Make sure the membrane covers the O-ring all
around its circumference.
9. Using the installation tool, screw the membrane lock back into the cap.
Tighten the lock firmly over the membrane and O-ring, but do not over
tighten.
10. Inspect the membrane for wrinkles. If wrinkles exist, remove the membrane
and repeat steps 8 – 10.
11. Fill the membrane cap with water and inspect the bottom for leaks. If water
drops are leaking from the membrane, re-seal the membrane on the O-ring
(repeat steps 8 – 11, for membrane replacement only).
If the assembly is leak-free, empty the water and fill the membrane cap with
electrolyte to the brim.
12. Tap the side of the housing gently to remove any air bubble that may be
sticking to the membrane.
13. Screw the cap onto the probe. Excess electrolyte will drain out.
14. Replace probe guard.
15. Calibrate the probe after the % saturation readings have stabilised.
Note: Membranes can only be used once. When a membrane cap is screwed
onto the probe, the membrane is stretched by the cathode. If the same O-ring
and the membrane is used a second time it will not fit perfectly onto the
cathode. This will result in erratic readings.
Electrolyte Solution
The electrolyte solution in your probe's cap will deplete on usage and will need to
be replaced periodically. Your new DO probe comes with accessories of one
replacement electrolyte solution and a spare membrane cap. The replacement
electrolyte comes premixed and ready to use. To order more electrolyte solution,
see "Accessories" section.
DO Measurement Considerations
The amount of DO that can be held by water depends on 3 factors: water
temperature, salinity, and atmospheric pressure; Amount of DO increases with
decreasing temperature (colder water holds more oxygen). Amount of DO
increases with decreasing salinity (freshwater holds more oxygen than saltwater does). Amount of DO
decreases with decreasing atmospheric pressure (amount of DO absorbed in water decreases as
altitude increases). The chart below shows the solubility of DO in mg/l in water at various temperature.
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