Assessment of noise level emitted by micro tractor in static and dynamic conditions

Abstract

Noise is a complex mixture of sounds that causes the feeling of discomfort and is continuously present in the daily lives of human beings. The objective of this study is to assess the noise level emitted by a micro tractor in various situations. In the first situation, the micro tractor is standing still and is subjected to 600, 800, and 1100 rpm from four positions -right, front, left, and rear sides -as well as four distance radii -1, 2, 5, and 10 m. In the second situation, the micro tractor is in motion and is subjected to three operational gears (1st, 2nd, and 3rd) at 1100 rpm with two types of soil surfaces -hard and mobilized. The results reveal that noise levels increase with an increase in the number of engine rotations and they decrease with an increase in the distance radius; this can be observed in all three situations considered in the assessment. Further, it is verified that there is no difference between surfaces in terms of the noise level, and the average value for the hard soil and mobilized soil is 89.5 dB(A) and 91.7 dB(A), respectively. However, for both surfaces, the values are above the threshold of 85 dB(A) for an eighthour work shift. Key words: Noise level, ergonomics, machines ResumoO ruído é um complexo de sons que causam sensação de desconforto e está presente de forma contínua na vida diária dos seres humanos. Objetivou-se com este trabalho avaliar o nível de ruído emitido por um microtrator sob diferentes situações: a primeira com o microtrator parado submetido às rotações de 600, 800 e 1.100 rpm em quatro posições em relação ao microtrator: lados direito, frontal, esquerdo e traseiro e quatro raios de afastamento: 1, 2, 5 e 10 m e a segunda com o microtrator em movimento submetido a três marchas de trabalho (1ª, 2ª e 3ª) a uma rotação de 1.100 rpm em duas superfícies de solo (firme e mobilizado). Os resultados mostraram que o nível de ruído aumenta com um incremento da rotação do motor e diminui à medida que o raio de afastamento aumenta, isso pode ser observado para as três rotações avaliadas. Verificou-se que não há diferenças entre as superfícies, para o nível de ruído, sendo o valor médio para o solo firme de 89,5 dB(A) e de 91,2 dB(A) para o solo mobilizado, mas em ambas as superfícies, os valores estão acima do limite de 85 dB(A) para uma jornada de oito horas. Palavras-chave: Nível de ruído, ergonomia, máquinas

Characterization of noise emitted by a power tiller through geostatistics

“…However, the use of PPE is still recommended for all workers involved in this machine operation. The minimum noise value produced by this tractor was around 73.5 dB (Table 1) observed in point (4, -10), i.e., the farthest from the source, corroborating with results found by Magalhães et al (2012); Pimenta ; Nascimento et al (2013) and Missio et al (2015).…”

“…Baesso et al (2015) evaluated 12 tractors of different models and concluded that tractors without a closed cabin had noise levels close to the operator's ear above the levels allowed by NR 15, being necessary the use of ear protectors. Studies performed by Rinaldi et al (2008), Alves et al (2011) and Nascimento et al (2013) also concluded that farm machinery noise levels were above tolerance limits, being needed to take measures to reduce or eliminate the risk which the workers were exposed in the agricultural operations.…”

Ergonomic and Safety Conditions Assessment of Tractors Used by Smallholders According to Brazilian Legislation and Current Standards

“…They found that most of the tractors emitted noises higher than the threshold established in NR 15. Also, Nascimento et al (2013) reported the results of a work with a walking tractor, disclosing that the tractor presented unsatisfactory high levels of noise and, therefore, suggested that the operators of these machines should use personal protective equipment full time.…”