Whole body vibrations of tractor driver in citrus orchard

This paper reports the results of the first analyses carried out to evaluate the vibration level the tractor driver is subject to during pesticide application in a citrus orchard. The measurements were carried out during ordinary working conditions by using a triaxial accelerometer placed on the seat of a 4-wheel (all with the same diameter) drive tractor. The sprayer used was a trailed conventional one with hydraulic pulverisation and axial fan. The vibration exposure was computed globally and for each working phase (transfer, spraying, turnings, transients, etc.). The main results showed that, with reference to the whole working cycle, the weighted root mean square (RMS) values of acceleration (around 0.6 m/s2), were always slightly higher than the daily exposure action value fixed by the 2002/44/EC directive; among the different working phases, the highest values of acceleration occurred during transfers from and by the farm centre, where the tank of the sprayer was filled, due the higher forward speed. Finally, the FFT analysis showed the main harmonic between 35 and 37 Hz, corresponding to the engine speed. Furthermore, other lower frequency harmonics, at around 2–3 Hz, were present, due to the forward movement of the tractor.