How to install an Automatic Weather Station?
Depending on the level of complexity of your installation, you may require multiple technicians to help you.
Any installation dealing with Alternative Current (AC) should be performed and verified by a trained and Accredited Electrician.
Installing an Automatic Weather station
Prior installation, unsure that you prepared all pertinent site information, including the latitude and longitude, local magnetic declination, prevailing wind direction, as well as topographic maps and site photographs that show the exact tower location.
Tilt Tower installation
The tilt-up tower will be outfitted in a horizontal position. To orient the sensors properly, you will need to establish which position on the horizontal tower represents North. This will now be a simple task since north will be either straight up, straight down, or directly left or right. If the tower cannot be laid out along a principal direction, the angle of deviation must be determined and documented for the proper orientation of the sensors.
Raising the tower into the principal wind direction and lowering with the principal wind direction generally offers additional stability. As required, secure and control the tower with appropriate anchoring systems to ensure stability.
- Mount the upper-level wind sensors at least 0.3 m (1 ft) above the tower top to minimize potential tower shading effects. Mount sensors on independent mounting booms. For sensors positioned off the side of the tower, use mounting hardware that is horizontally level and long enough to position the sensor at least three tower widths out from lattice-type towers and six tower diameters out from tubular towers. For triangular lattice towers, the tower width is measured as the length of one face. Orient sensors mounted off the tower side into the prevailing wind direction, or, if there is more than one prevailing direction, in a direction that minimizes the probability of tower and sensor shadow effects. Sensor drainage holes must not be blocked by the vertical mounting hardware to prevent internal freezing damage during cold weather. Tubing, not solid stock masts, should be used. Wind vanes should be oriented so its deadband position is not directed towards the prevailing wind. The deadband should be positioned at least 90 degrees away from the prevailing wind direction, preferably in a principle direction.
- Mount the temperature sensors at least one tower diameter away from the tower face to minimize tower heating effects. Orient the sensor on the tower for maximum exposure to the prevailing wind direction to ensure adequate ventilation.
- Place desiccant packs in the data logger enclosure to absorb moisture. House the data logger, as well as cabling connections, telecommunication equipment, in a weatherproof and secure (locked) enclosure. Mount the enclosure at a sufficient tower height to allow for above average snow depth and to deter vandalism.
- If applicable, position the solar panel above the enclosure to avoid shading, oriented toward the maximum sunlight and near vertical to minimize dirt build-up and maximize power during the winter’s low sun angle.
- Ensure that all cabling that enters the equipment enclosure has drip loops. Seal all openings in the enclosure, such as knock-outs, to prevent damage from precipitation, insects, and rodents.
- If applicable, orient the cellular communication antenna at an easily accessible height.
- Seal sensor terminal connections with silicone caulking and protect from direct exposure. Wrap sensor cabling along the length of the tower and secure it with UV resistant wire ties or electrical tape. Where chafing can occur between the sensor wire(s) and the support structure (e.g., tilt- up tower anchor collars), wrap tape around the sensor wire and leave sufficient slack.
- Investigate the incidence of lightning activity for your application. For high frequency areas, take the conservative approach and increase the grounding system capabilities.
- As required for your application, you may need to take additional Transient Protection Measures.
All sensor equipment must be tested for proper operation on the tower before a tilt-up tower is raised. These functional tests should be repeated once the installation is complete. Having spare equipment on hand makes repairs easy if problems are found during these functional tests.
- Ensure that all sensors are reporting reasonable values and verify that all system power sources are operating.
- Verify required data logger programming inputs, including site number, date, time, and sensor slope and offset values. Ensure that the data logger is in the proper long-term power mode.
- Verify the data retrieval process and perform a successful data download on your local computer, then compare transmitted values to on-site readings.
- Secure the equipment enclosure.
- Finally, document all pertinent observations.