Vibra？？o e ruído emitidos por dois tratores agrícolas

tractor driving imposes a lot of physical and mental stress upon the operator. the aim of this work was to evaluate the vibration and noise levels emitted by tractors with different ages, under different motor rotations (1700, 1850 and 2000 rpm). in the evaluations, two agricultural tractors (a 1988 model year with 60.35 kw of power and a 2009 model year with 89.06 kw), without cabin were used, working with a plough. the noise evaluations were made with a sound level meter, in the driver's position. the vibration evaluations were made on the driving seat using an automatic acquisition data system with three accelerometers, in the vertical and horizontal planes. the results showed that the service with the tractors presented noise levels higher than the 85 db(a) limit for 8 hours of daily exposure, established by the brazilian legislation on insalubrity. the need of hearing protection device use by the machine operators was observed. the older tractor presented vibration levels that could compromise health, safety, comfort and efficiency of the driver. this not occurs for the newer tractor.