Nível de ruído emitido por tratores agrícolas com diferentes sistemas de aspiração de ar e plataformas de operação

Abstract

For many years man has adapted to the machine, without considering the important ergonomic factors, causing serious occupational health problems. According to the World Health Organization (WHO), noise is one of the main occupational sources that generate worker incapacity over the years. This can be defined as undesirable and unpleasant sounds, which are caused by several factors in disharmony. Aiming at the comfort and safety of tractor operators, it is increasingly common to use cabins in the operating system, which work as a reflective and absorbing surface, reducing operator exposure. Another point that significantly impacts the increase in noise in tractors is the air suction system. In this context, the present work aimed to evaluate the noise levels emitted by agricultural tractors with different air suction systems and operating platform. Four tractor models were tested, varying the tests in five rotations and four different collection positions, totaling 400 readings. After collecting the test information, the data were submitted to the F test using the Minitab Software, where the means that were significant were submitted to the Tukey test at 5% error probability. It was found that, in all tractor models, with the increase in the engine rotation level, there was an increase in noise levels. The impact of the intercooler on the turbo engine was verified, as an element that generates higher noise levels, with the TT75 tractor obtaining the highest values. The presence of the cabin mitigates the exposure of sound pressure by the tractor driver, but it can accentuate the noise to nearby workers. The TL5.80SC tractor presented the lowest noise average, while the same model with cabin only had a lower value in the collection position close to the operator's ear. All mean values, regardless of the equipment and collection position, obtained a noise level above 85 dB(A), considering an 8-hour workday would already be a higher exposure level than that prescribed by NR-15.