Whole-body vibration transmitted to the framesaw operator.

At the moment there are more than 40 framesaws in use in Croatia, and many framesaw operators have a serious spine problem. Complex measurements have been carried out in order to determine the vibration level on the operator's seat. This paper reports and analyzes the measurement results of the whole-body vibration transmitted to a framesaw operator during an ordinary working day. Vibrations were measured at all operations performed during the normal framesaw working cycle. For all the measurements frequency spectra were obtained and the results graphically represented according to the ISO 2631-1-1986 recommendations. The weighted r.m.s. acceleration was also calculated and the duration of each single framesaw operation was measured. The energy-equivalent vibration level, corresponding to the total duration of exposure was calculated, too. The values so obtained were compared with the daily exposure limits according to the ISO 2631-1-1997. The measurement results showed that the framesaw operator, under the given measuring conditions, is exposed to a higher vibration level than the given daily exposure limits. Also, the energy-equivalent vibration level calculated according to the guidelines given in the new ISO 2631-1-1997 is higher than the limits recommended for an effective 4-h daily exposure.