TURTLE
TOUGH
®
15
Sensor Refurbishment
Refurbishment is recommended every six months and also whenever the membrane has been damaged. The
refurbishment procedure involves both electrolyte replacement and membrane replacement. This ensures that
no foreign substances can get into the electrolyte in the case of a damaged membrane.
Steps for replacing the electrolyte and the cathode-membrane:
1. Unscrew protective cap or paddle holder.
2. Pull off the first red collar.
3. Pull off the O-Ring.
4. Pull off the second red collar, remove the old membrane.
5. Unscrew the side pressure membrane ring nut with the Pressure Compensator
Tool TT-TOUGH-DO-SWT or a set of Circlip pliers. Remove the o-rings and
side membrane.
6. Shake out the old electrolyte, taking care not to knock against anything with
the sensor
7. Hold the sensor slightly at an angle and fill up with new electrolyte. Gently
tapping against the sensor body helps to release trapped air bubbles.
8. Replace the membranes and o-rings back in position and screw in the ring
nut. Use a small cloth or tissue-paper for wiping off any electrolyte spilt
during fastening of the screw in cap.
Note:
If the electrolyte comes into contact with your skin, rinse the affected part
immediately under running water.
9. Hold the sensor vertically and check whether electrolyte is visible in the white
electrolyte channels next to the cathode.
10. If this is not the case make ”pumping movements” with your thumb on the
pressure-compensation membrane until electrolyte appears in all the electrolyte
channels.
Note:
Never use a needle or other sharp objects to create flow, since the white
wick-like insert would otherwise be damaged! Doing this voids the warranty.
11. Wipe the cathode clean with tissue-paper, but do not polish it because the
“scratched” surface helps to form a film of the electrolyte.
12. Put one drop of electrolyte onto the cathode.
13. Put on the membrane and pull slightly downwards at the comers; there must
be no wrinkles formed on the silver surface. You can also use a Membrane
Positioner TT-TOUGH-DO-MP for this. (see: Using the Membrane Positioner).
14. Replace the red collar (with the smoothed-off edge forward) and push it down
until the groove of the O-Ring is again visible (but no further!).
15. Fit the O-Ring.
16. Subsequently fit the next red collar (with the smoothed-off edge forward).
17. Use a sharp knife to cut off any projecting membrane material below the
second red collar.
18. Rinse membrane with water.
19. Screw on protective cap or paddle holder.
Note:
Wait at least 30-45 minutes before carrying out recalibration. For accurate
measurements it is recommended to leave the sensor overnight to stabilise and then
recalibrate the next day. The waiting period is necessary because the Teflon material of
the membrane expands slightly during fitting, but will always shrink back to its original
size. This is also indicated by the liquid-crystal display. Immediately after sensor
refurbishment the value is relatively high and then falls progressively over time.
Please read the relevant sections of this manual with regard to the special points to be
observed when changing the electrolyte or the membrane
.
