Courtesy of the Gibbons Family the Ultrasonic Anemometer has been located on the summit of Inish Lyre 53° 49.5'N 9° 39'W, 27 meters above sea level which provides a clear view of all quarters enabling a representative sampling of the local wind in Clew Bay .
Principle of Operation
The can-sized wind sensor measures the time taken for an ultrasonic pulse of sound to travel from the North transducer to the South transducer, and compares this with the time for a pulse to travel from S to N transducer. Likewise times are compared between the W and E and the E and W transducers. If for example a N wind is blowing, then time taken for the pulse of sound to travel from N to S will be faster than from S to N, whereas the E to W and W to E times will be the same. The wind speed and direction are then calculated from the differences in the times of flight on each axis. This calculation is independent of error sources such as temperature and mechanical friction etc.
Being solid state the Anemometer is hopefully virtually maintenance free. It is powered by battery which is kept charged by a large solar panel.
Using a datalogger and a modem the data is sent via GPRS and the internet to a remote computer where the Wind Speed and Direction for the last 8 hours are displayed on two graphs which scroll forward with time.
Data is collected every 30 secs. and the Graphs are updated every 5 mins when the remote computer polls the datalogger. These real-time graphs are available on www.mayosailingclub.com for members to check the current local weather at Clew Bay anytime. This is an important safety feature for members and the general public who use Clew Bay.
Wind Speed:- 0 to 114 knots; Accuracy +/- 2% (2kts); Resolution 0.02kts.
Wind Direction:-0 to 359° ; Accuracy +/- 3° Resolution 1°