![Aquaread Aquaprobe AP-7000 Скачать руководство пользователя страница 54](http://html.mh-extra.com/html/aquaread/aquaprobe-ap-7000/aquaprobe-ap-7000_instruction-manual_2960645054.webp)
Aquaprobe
®
AP-7000 Instruction Manual
10401-00894 Rev M
15. Optional Optical Electrodes Calibration and Maintenance
The AP-7000 is constructed with an aluminium sleeve surrounding the delicate sensing
electrodes. The Sleeve can be easily removed by unscrewing to allow cleaning of the
individual electrodes, however,
The Probe sleeve, end cap and wiper form an integral,
working part of the Probe’s optical measurement system, and MUST be fitted during
calibration and measurement for correct operation.
All Aquaread
®
Optical Electrodes are incredibly sensitive. For example, the Turbidity
electrode is capable of measuring between 0 and 3000NTU with an internal resolution of
greater than 0.1NTU. This means that the electrode is able to detect changes in turbidity
that are less than 0.003% of the full range! The other optical electrodes have a similar level
of sensitivity.
It follows, therefore, that in order to provide stable, repeatable readings, the environment in
which the measurements are made must be completely stable and repeatable.
For this reason, the AP-7000 is constructed
with a matt black aluminium sleeve and end
cap that enclose the sensing electrodes and
provide a closed, constant condition, non
reflective measurement chamber.
In order to obtain consistent results, the
measurement chamber created within the
Aquaprobe
®
must remain physically
constant during both calibration and
measurement. It is therefore essential that
both the sleeve and sleeve end cap are
fitted during calibration and operation of
all types of optical electrodes.
If an optical electrode is calibrated under one
set of conditions then used to measure under
another set of conditions, the readings will
naturally be erroneous, especially at low
concentrations.
A perfect example of this is calibrating with
the end cap removed then measuring with the
end cap fitted (or vice-versa).
By changing the physical characteristics of the measurement chamber, you also change
the calibration and response of the electrode.
Another particular problem when trying to measure very low concentrations is air in the
form of both visible and microscopic bubbles. These act like tiny prisms and can refract and
reflect both the excitation light and the return signal being measured.
© 2017 Aquaread
®
Ltd.
www.aquaread.com
Page 54 of 143