The XL2 meters were housed in Pelican cases with the XL2 preamplifier extension cable threaded through an aluminum tube with a weatherproofing gland at the top to protect and seal the preamplifier connection. The XL2 was battery powered to enable continuous noise logging for two weeks at a time at each residential site. Special windscreens, 200 mm in diameter, were used to reduce the impact of wind noise on the microphone. The recorded data was then processed in accordance with the relevant standards specified in the conditions of consent for wind farms. For example the following chart illustrates the LA90 level, which is the statistical noise level exceeded during 90% of the measurement period, depending on the wind speed shown on the X-axis.
Chart with 3'773 individual LA90 data points in reference to the wind speed