Spatial analysis of the noise emitted by a farm tractor

Abstract

Among the equipments used in a farming operation, the tractor is the principal. During working hours the operators are subjected to various intensities of noise, making it necessary the development of tractors and environments more suitable for users of this machine.This study demonstrates the  behavior of the noise level emitted by a tractor when it is working under different environment due to clearance radius at different engine speeds. The experiment was conducted at the EMATER experimental station in Anápolis – GO. A New Holland tractor, power 55.1 kW (75 cv), was used as a source of noise. The noise level was performed by a digital sound level meter according to parameters established by NBR 9999. For measurement of noise in different environments, a shed of 250 m² was used as indoor environment and a field free of obstacles such as open environment. The radius of removal was determined by five different distances (1, 2, 3, 4 and 5 m) and in four different directions in relation to the tractor. The engine speeds were 1000, 1500, 2000, 2500 rpm. For the interpretation of data, two experiments were carried out in a completely randomized, with three replications, interpreted by the Tukey´s test (5%) and geostatistics. The geostatistical analysis showed satisfactory to the behavior of the noise around the tractor. Care in relation to the level of noise emitted by the tractor must be sharp when used in stationary operations indoors.