Aquameter
™
Series Instruction Manual
10401-00188 Rev M
12. General Probe Maintenance
Each Aquaprobe is constructed with a two-part protective aluminium sleeve surrounding
the more delicate sensing electrodes. To gain full access to the individual electrodes for
periodic maintenance and thorough cleaning, first unscrew the lower half of the sleeve.
Next, remove the four small black countersunk screws from around the top of the upper
sleeve, then gently slide the upper sleeve off the Probe body being careful not to damage
the individual electrodes.
TIP
: If you find one of the sleeve screws to be excessively tight, turn the Probe over and
undo the screw directly opposite it. This will release the tension on the tight screw and
allow its easy removal.
With the sleeve removed, the individual electrodes are very vulnerable, so please handle
the Probe with extreme care. If you drop it, it’s going to break!
Once any maintenance and cleaning has been carried out, replace the upper Probe sleeve.
Before inserting the sleeve screws, apply a little silicone grease or similar lubricant to each
screw hole and screw.
This will ensure that next time you remove the screws, they will
come out easily. If you do not grease the screws, they may corrode into the Probe body
and snap off when you try to remove them.
This is not covered by your warranty.
Finally, tighten the screws and re-attach the lower sleeve. The Probe Sleeve must be
absolutely rigid with respect to the Probe Body. If you can move the Probe Sleeve to and
fro whilst holding the Probe Body, tighten the four screws further before re-calibration.
The complete Probe sleeve forms an integral part of the Probe and is essential for correct
operation.
Removing and replacing the upper Probe sleeve will alter the Probe’s
characteristics, so
full re-calibration is essential
after removal and replacement.
12.1. Identifying The Individual Electrodes
The photograph on the right shows an AP-600. If you
have purchased an alternative model, some of the
electrodes shown may not be fitted.
1. pH (shown) or ORP or combined pH/ORP
Electrode (see note below).
2. Turbidity Receiver Electrode. The polished, 4mm
diameter centre section is the lens.
3. Galvanic Dissolved Oxygen (DO) electrode. The
clear plastic sheet stretched across the tip is the
membrane. DO NOT TOUCH!
4. Turbidity Transmitter electrode. The domed, 4mm
diameter section is the lens.
5. Replaceable DO Membrane Cap.
6. Electrical Conductivity (EC) sensing contacts.
Aquaprobe Models AP-100, AP-400, AP-500 or AP-600 may be fitted with either a pH
electrode or an ORP electrode. ORP Electrodes can be identified by a single platinum wire
in place of the glass bulb on the tip. Aquaprobe Models AP-700 and AP-800 are fitted with
a combined pH/OPR electrode, which has both a glass bulb and a platinum wire sitting side
by side. Aquaprobe models AP-900 & AP-1000 are fitted with optical DO electrodes.
© 2011 Aquaread Ltd.
www.aquaread.co.uk
Page 25 of 64
