Hach ORBISPHERE 32301 Manuel D'utilisation De Base page 7

5. Pour standard ORBISPHERE model 2959GP electrolyte into the regeneration cell so that it
covers the electrode.
6. Turn the selector knob (No. 4) to the cathode position and press the TIMER switch (No. 5). The
warning light will come on and remain on for 60 seconds while cleaning takes place.
7. Observe the solution in the regeneration cell. From being a clear liquid it should fill with small
bubbles given off at the cathode. This has the effect of darkening the solution. If at the end of the
60 seconds cleaning period an abundant development of bubbles from the cathode is not obvious
then press the TIMER switch once more. The development of bubbles is a sign of a clean
electrode.
8. Turn the selector switch to guard and press the TIMER switch. Again watch for bubbles and
repeat the cleaning process if necessary.
9. Turn the selector switch to anode and press the TIMER switch. Here the bubbles may be more
reluctant to appear and you may need to press the TIMER switch several times before you are
satisfied that the anode is clean enough, particularly for ozone sensors.
10. Important: If cleaning an GA2x00 or C1100 sensor, skip this step and continue at Step 10. If
after five cleaning periods bubbles do not appear then pour out the cleaning liquid, remove the
regeneration cell, and carry out a chemical cleaning of the sensor as described in the sensor
manual. Complete the cleaning with the 32301 unit by going back to Step 3 above.
11. Once the three electrodes are clean, disconnect the counter electrode and sensor and empty the
cleaning solution from the regeneration cell.
12. Rinse the interior of the regeneration cell and sensor with water.
13. Based on the model used, remove or unscrew the regeneration cell from the sensor head and
again rinse both well with water.
14. Visually inspect the three electrodes. They should appear clean and of a uniform color. If there
are any dark patches, particularly on the anode, repeat this cleaning process until any such
patches disappear.
Figure 4 Orbisphere DG33620 EC cleaning sensor support
3.1 Replace the membrane
Once cleaning is complete prepare the sensor for reuse.
1. Important: If cleaning an GA2x00 or C1100 sensor, skip this step and continue at Step 2. Follow
the sensor face polishing instructions described in the sensor operator manual supplied with the
sensor.
2. Install a new membrane and electrolyte to the sensor. Refer to the operator manual delivered with
the sensor for details on how to do this as the procedure is different depending on the type of
sensor.
3. Rinse excess electrolyte off the sensor with water.
4. The sensor can now be calibrated and returned to service.
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