Vibrations are dynamic phenomena occurring in elastic or quasi-elastic media after a local excitation and becoming manifested by propagating the excitation within the medium in the form of some elastic oscillations. Thus, depending on the phenomenon dynamics, there can be met vibrations with low variation frequencies, characteristic to the mechanical structures, structures in constructions and earthquake waves, as well as vibrations with high variation frequencies. The vibration measuring is performed on a straw cereal harvesting machine with an axial threshing apparatus ("CASE IH") in two conditions: in a stationary position and during work, by using transducers for each of the main working parts of the harvester: thresher, header (stripper), chassis and operator's chair. On the basis of the values of longitudinal, cross and vertical accelerations, measured at various frequencies in the two operating conditions of the harvester (at stationary and during work), the effect of the vibrations is established on each of these parts and, finally, cumulated, the vibrations sent to the operator's chair, the nomograms following to be traced and to be established the range with the limits up to which these are not dangerous for the operator's health.

Vibrations are dynamics phenomenon which appear in some environment as a result of an external force whose action consist on an oscillation. The effect of these oscillations harm to the environment where they appear and if this environment is the human body then the results are more harmful, hauling consequences, sometimes irreversible, on the health of the human body. In this respect, studying and knowing the effects of the vibrations on human body have become a necessity, the research taking place in order to find out the limit to which the men could work in an environment with vibrations such as the agricultural machinery (selfpropelled combines for cereals crop in a way) without no effects on the health of human being.