HWM Multilog LX 2, User Manual, Page: 17 / 56

16
Antenna installation considerations
The method of installation at site should be carefully selected.
Signal strength within the cellular network can vary dramatically even within
the same cell; proximity to the transceiver, type of antenna, position and
angular orientation of the antenna, all have a significant effect on the ability of
a device to reliably communicate with the cellular network. To ensure reliable
GSM/GPRS data communications it is essential that the most suitable
antenna is selected and it is mounted in the most appropriate location.
Installing a device without considering the type of antenna and its installation
constraints can lead to disrupted and unreliable data communications and
accelerated battery consumption. The following gives practical advice on how
to minimise potential problems.
General Considerations

Always perform multiple signal strength tests moving the antenna to
different positions (please see below for description of signal strength
test results).

When performing Signal Strength Tests ensure that the chamber
lid/cabinet door is in as close to normally closed position as possible to
ensure an accurate result.

Deploy the antenna as close to the surface as practically possible,
especially when installing in a large chamber.

If the device is installed in an underground chamber consider, where
possible, locating the antenna in a secure position outside the
chamber.

Ensure that the antenna connector is in good condition and correctly
tightened (finger-tight is not sufficient for the type of connectors used).
Adequate tightening of the connector reduces the risk of water ingress
and thereby signal attenuation as a result of changes in impedance.

Never attempt to modify the dielectric seal of the antenna connector, it
is designed to keep moisture away from conducting parts which lead to
corrosion and attenuation.

Consider using secondary environmental protection for the antenna
connector such as self-amalgamating tape.

If a logger is installed in a chamber that is likely to flood (e.g. an
Atlantic Plastics chamber), position the logger upside-down in the
chamber to avoid unnecessarily submerging the antenna connector.

Use the shortest possible antenna lead and ensure that there are no
kinks or tight radius bends in the cable. A kinked cable can cause
signal loss .

Where long transmission leads are required, consider using a low-loss
alternative to corrugated copper cables, e.g. Times Microwave white
braided coaxial cable.

The signal emitted from any antenna submerged under water will be
significantly attenuated; place the antenna in a location where it will not
become submerged.

Always ensure that the latest firmware is installed in the device.
Meter and
Pulse Unit