Vibration and noise of small implements for soil tillage

Small cultivators can represent the main or the sole mechanical resource for agriculture in many countries. For such constant use, their ergonomic characteristics can assume a great importance. In this paper, the vibration and noise of some of these implements-one of which is made in China-were examined. The acceleration transmitted from the handle and the noise level at the user's ear were measured during soil tillage, according to International standards. The results indicate that in 10% of the exposed population, vascular disorders of the hand (Vibration White Finger) can appear after three years of continuous use of these machines, under usual working conditions. The level of noise at the worker's ear should not involve an appreciable risk for hearing after 10 yr of use. For the noise levels experienced on the majority of the implements examined, the domestic and European directives require that the worker need only receive appropriate information about the problems due to the noise. In view of the introduction and promotion of these implements in China and in the developing countries, it is necessary at least to reduce the vibration transmitted to the user's hands, by providing adequate insulating systems for the handle. (C) 1999 Silsoe Research Institute.