Research of vibro-acoustic environment in cabs of agricultural tractors

Abstract

The working conditions of the operator of agricultural machinery depend on many factors such as microclimate, ergonomics, noise, vibration and changes over time in respect to the usage intensity. The quality of the workplace from the perspective of human safety and health is unchallengeable at modern machinery but unfortunately the ratio of old to new tractors is still very high. The statistical data of the registry of the Republic of Lithuanian agricultural machinery show that the majority (more than 50 %) wheeled tractors were manufactured in 1990’s or even earlier.This machinery is known as insufficient to guarantee healthy working conditions, therefore the relationship between the machinery used in farms is slightly related to the number of occupational diseases (especially NIHL and musculoskeletal). This shows the necessity to investigate the vibroacoustic environment which is, according to various sources and our research data, between 80-90 dB(A) in these tractors. Similar tendencies were obtained analyzing the results of the whole body (WBV) and hand-arm vibration (HAV). It was found that theWBVacceleration values of more than 05 m·s-2 were exceeded in 80 % of all tractors while the HAV exposition value of 2.5 m·s-2 was exceeded at 33 % of all workplaces respectively.