Certikin CTX QPA5S11001CT Notice D'installation, Mode D'emploi, Notice D'entretien page 53

Installing a pre-filter of 50-80 µm upstream of the one installed on the station is often recommended, particularly
in the case of outdoor swimming pools where the water is sampled directly from the pool
The filters must be cleaned at regular intervals and replaced so that measurements are not disturbed by
the consumption of chlorine that would otherwise take place.
Use of a pump can also be recommended when water sampling is not pressurised. This system also helps
prevent long delays even when the sampling point is at a considerable distance from water sampling.
Figure 7 shows how the pump transports the water over a long distance, but only part of the flow is used for
actual measurement. In no event must the throttle valve be completely closed, otherwise the long delay can
make it more difficult to control. Also, the water might heat up significantly in the pump, and thus lead to
incorrect measurements. A pressure meter in the sampling node is useful to regulate the throttle valve.
Draining water from the sampling station is at almost nil pressure. The water must be able to drain freely. On the
other hand, a pump must be installed if the water sample goes back to a pressurised system.
With reference to Figure3, respectively connect:
Pos 1: supplied water inlet pipe 4 x 6
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Pos. 4: measuring cell output, 4 x 6 supplied pipe.
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pH and RX electrode assembly
To assemble the electrodes (Figure 8, pos. D), proceed as follows:
Loosen the ring nuts of the relative electrode holders.
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Remove the protective caps of the sensitive membrane of the electrodes.
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Insert the electrodes, being careful to leave less than 10 mm from the bottom of the Plexiglas seat
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in the probe holder (Figure 8, pos. A)
Be careful to make sure that the distance indicated by "B" is more than 2 mm.
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Manually tighten the ring nuts (Figure 8, pos. C), being careful to avoid breaking the transparent
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plastic of the said electrodes
Figure 7 – Typical installation with a recirculation pump
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