Gill Instruments Ltd
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MetPak/MetPak RG and MetPak Pro Base Stations
Page | 42
Issue 1
Doc. No. 1723-PS-0023
October 2018
5.2.
Interference
As with any sophisticated electronics, good engineering practice should be followed to ensure
correct operation.
Always check the installation to ensure the Base Station and Wind sensor is not affected by other
equipment operating locally, which may not conform to current standards, e.g. radio/radar
transmitters, boat engines, generators etc.
Do NOT mount the Base Station Wind Sensor in close proximity of high-powered radar or radio
transmitters. A site survey may be required if there is any doubt about the strength of external
electrical noise.
Guidelines –
Avoid mounting in the plane of any radar scanner – a vertical separation of at least 2m should be
achieved.
Radio transmitting antennas, the following minimum separations (all round) are suggested
VHF IMM – 1m
MF/HF – 5m
Satcom – 5m (avoid likely lines of sight)
Ensure the product is correctly earthed in accordance with this manual.
Use cables recommended by Gill, keeping the length below the maximum allowed. Where the
cables are cut and re-connected (junction boxes, plugs and sockets) the cable screen integrity
must be maintained, to prevent the EMC performance being compromised.
Earth loops should not be created – earth the system in accordance with the installation
guidelines.
Ensure the power supply operates to the Base Station and Wind Sensor specification at all times.
5.3.
Wind Sensor Installation
Avoid turbulence caused by surrounding structures that will affect the accuracy of the Wind Sensor
such as trees, masts and buildings.
The World Meteorological Organisation makes the following recommendation:
The standard exposure of wind instruments over level open terrain is 10m above the ground.
Open terrain is defined as an area where the distance between the sensor and any
obstruction is at least 10 times the height of the obstruction.
If mounting on a building then theoretically the sensor should be mounted at a height of 1.5
times the height of the building.
If the sensor is to be mounted on a mast boom, part way up a tower or mast, then the boom
should be at least twice as long as the minimum diameter or diagonal of the tower. The boom
should be positioned on the prevailing wind side of the tower.
It is important to ensure that the Wind Sensor is mounted in a position clear of any structure, which
may obstruct the airflow or induce turbulence.
Mount the Wind Sensor so as to have a clear view of prevailing winds.
The Wind Sensor should be set to point North (or to another known reference direction), using the
North Pointers, which can be identified by arrows or dots or an alignment notch to aid alignment
(see the illustrations in para 2.1.3).
