Variabilidade Espacial do ruido de Tractor

AbstractThe objective was to analyze the spatial variability of noise levels caused by farm tractor in the workplace and develop tractor noise levels maps to in the maximal revolution per minute in drawbar based on geostatistics and to verify if the levels are within the acceptable human range . Sound pressure levels ranging from the lamiar of audibility and the pain lamiar are just corresponding to sound pressure, however there was a need to convert them on a logarithmic scale, resulting in range more easily manipulated (0 to 140dB. One of the ways to evaluate and characterize the noise levels in the workplace is through the use of geostatistics, which enables geospatial modeling allowing the interpolation using krigging, it allows maps provide accurate contours, (Vieira., 2000; Machado et al, 2007 was conducted surveys in square grid with sample spacing of 2x2 m, totaling 121 points in an area protected by break eucalyptus winds. The sound pressure values at the points will be collected in the early hours of the day to ensure less influence wind during the day, where at each point (coordinate) sample there will be a 10s stay to allow the dB reading does not oscillate at the same point. The spatial dependence of noise levels at two different engine speed points were analyzed by through semivariogram fit spherical by method of Least Squares ordinary and the spherical model. The classic semivariogram was estimated GS + program.