Syrinix PIPEMINDER S, Руководство по эксплуатации продукта

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6.6 Antenna Selection
PIPEMINDER-S is shipped with an omnidirectional antenna with the blade and Chamber antennas being
available as optional extras, see
Error! Reference source not found. . Guidance on antenna selection is given
When using the Chamber antenna it should be positioned with its top 100mm from the underside of the lid.
When using the omnidirectional antenna in a chamber care should be taken to:
•
mount PIPEMINDER-S such that the antenna is horizontal;
•
ensure that the antenna isn’t in close proximity to large metal objects;
•
position the antenna towards the top of the chamber around 100mm from the underside of the lid;
•
position the antenna near the lifting holes in the lid.
With any of the above antennas the installed orientation and position may be critical in achieving an
acceptable signal. The signal strength of different configurations can be compared by powering up
PIPEMINDER-S and observing the reported signal strength. In chamber installations,
this isn’t possible so the
device can be configured to send an SMS message containing the signal strength every 2 minutes for 20
minutes. The signal strength is also reported to, and visible on, the RADAR each time a connection is made.
Use of a GSM / GPRS signal tester to survey sites before deployment is recommended. The Snyper-3G from
Sequoia in the UK is a good example.
6.7 Deep Chambers
The need to place the antenna near the surface in deep chambers often presents a problem as the hydraulic
connection is generally at the bottom. In these situations, the preference is to extend the antenna connection
and keep the hydraulic connection short. Both whip and sub-manhole antennas are available, as special-order
items, with cable lengths of up to 10m.
Deep pipelines, and therefore chambers, are often found in regions where ground freezes to a large depth.
Caution should be taken to avoid placing the PIPEMINDER-S in a position where it may freeze in order to avoid
frost damage. See 3.5 Frost Protection.
Omnidirectional Antenna Blade Antenna Chamber Antenna
Chamber, metal
lid Requires good signal
strength above ground. Not suitable. Best choice, especially when
signal above ground is
weak.
Chamber,
composite lid Good choice. Not suitable. Only when signal strength
above ground is poor.
Building, above
ground Good choice. Good choice, allows
placement of
antenna on window. Not suitable.
Table 4: Antenna selection