Aquaprobe
®
AP-5000 Instruction Manual
10401-00906 Rev M
If a problem occurs during calibration, an error message will be displayed. Refer to
in section 10 for error message handling.
Remove the Probe from the calibration cup, rinse thoroughly in fresh water, shake off any
excess and dry the outer sleeve with a soft cloth.
14.6. Calibrating the DO 100% Saturation Point in Moist Air
1. Wash the probe thoroughly in fresh water, then shake off ensuring there are no
droplets adhering to the DO membrane.
2. Moisten a clean cloth or piece of tissue paper with fresh water and wrap it around
the open end of the probe ensuring all the holes are covered. Place the probe on a
flat surface. Do not hold the probe, the heat from your hands will warm the probe up
and interfere with calibration.
3. Switch the Aquameter
®
on and wait until the temperature measurement is
completely stable
.
This is very
important
.
4. Referring back to the screens shown in item 6 above select
DO100%
5. Wait while the Aquameter
®
carries out the calibration procedure.
6. When calibration is complete, the Calibration Report will be displayed.
The top line will display a value which represents the health of the luminophore. This value
should be between 0.8 and 1.5 (at 25°C). If the value returned is less than 0.8, the Optical
DO Cap should be replaced. These values are not stored in memory so should be noted
down in a calibration record book for the probe.
If a problem occurs during calibration, an error message will be displayed. Refer to
in section 10 for error message handling.
14.7. Replacing the Optical DO Cap
The Optical DO Cap contains a lens, which is coated with an oxygen sensitive
luminophore, which is in turn coated with a black rubber compound that provides optical
isolation but is permeable to oxygen. Oxygen molecules pass through the rubber into the
luminophore.
Never touch the black rubber end of the DO electrode as the oils in your
skin can block the pores in the rubber coating and stop it from working correctly.
The luminophore within the DO Cap will need replacing every few years, as it is a
consumable item. Since the luminophore is an integral part of the DO Cap, the entire DO
Cap is replaced. An Optical DO Cap can last up to ten years dependent upon the amount
of use it gets. See
in Appendix 1 for further details.
Caution: The inside of the Optical DO Cap is very sensitive to light and can be ruined
(bleached) if it is exposed to bright light for any length of time.
Never remove the Optical
DO Cap from the Probe unless you intend to replace it with a new one.
When replacing an
Optical DO Cap, do so under subdued light.
To replace the Optical DO Cap, follow these simple steps.
1. Remove the Probe sleeve.
2. Unscrew the Optical DO Cap from the end of the DO/EC electrode by rotating it anti-
clockwise.
Do not touch the exposed optical components.
3. Apply a light smear of silicone grease to the thread and O ring.
© 2019 Aquaread
®
Ltd.
www.aquaread.com
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