Aquacontrol Exclusiv 1,6 Mode D'emploi page 60

Among other things, the following indicators may suggest the electrodes are worn:
• The electrode requires an extremely long time to attain the value of the buffer
solution when calibrating.
• The electrode offset during the calibration process is too large.
• The KCL solution in the electrode shaft is used or discoloured.
Note: Electrodes wear very quickly if there is electrical potential in the pool
water!
Glass breaks are excepted from the guarantee.
5.2.2 Electrode care
• The pH sensitive membrane glass must be handled with care and protected from
damages.
• The inner reference solution of the glass electrode must cover the inner surface of
the membrane glass. Visually check the probes for trapped air bubbles. If air
bubbles are present, these can be removed by shaking in a downward position
(like a thermometer).
5.2.3 Cleaning the electrodes
If contamination on the glass membrane cannot be removed using soft, damp cloth, the
following cleaning agents may be used.
General deposits: Non-scouring household cleaning agent
Limescale or metal hydroxide: Diluted hydrochloric acid (approximately 0.1%-3%)
/ 1-5 minutes
Oils and fats: Solvents such as alcohol and acetone
Biological coatings: Solution of diluted hydrochloric acid and pepsin. Leave to work
for a couple of hours; Solvents (e.g. acetone) may not be used to clean electrodes with
plastic shafts since these may be attacked.
Generally speaking, rinse sufficiently after each cleaning process.
If the ceramic diaphragm for the reference system installed on the side is blocked, this
may be cleaned in the same way as the glass membrane and you may also carefully
scrape it with a fingernail, a razor blade or fine file. Pay attention to ensure that the
glass membrane is not scratched.
5.2.4 Calibration
pH probe
Calibration is carried out as described in the operating instructions (the device section).
If the deviation is too great or fails, the electrode must be replaced.
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