Rate of chainsaw vibrations in laboratory conditions and level of chainsaw noise at different distances

Abstract

The study is focused on the rate of vibrations and level of noise in the chainsaw model Stihl MS 362 which belongs in the group of the best-selling professional chainsaws in the world with a highly efficient anti-vibration system. Testing cuts to determine the rate of vibrations were made on the stems of two tree species: sessile oak (Quercus petraea (Matt.) Liebl.) and Norway spruce (Picea abies (L.) H. Karst.). The purpose of noise level measurement was to compare the influence of chainsaw noise on its operator and on the person occurring behind the zone of protection (5 and 10 metres) from the source of noise. Then a distance from the chainsaw was measured where the level of noise reached 80 dB. The measurements were performed according to ČSN EN ISO 22868:2021. At measuring the chainsaw vibrations, the rate of vibrations acting on both operator’s hands (front and rear grip) was examined. Vibrations were measured according to ČSN EN ISO 22867 (2012). It was found out that the rate of vibrations on the rear handle was in both cases of measurements higher than the rate of vibrations on the front handle. At the same time, a higher rate of vibrations was recorded in sessile oak. As to the level of noise, results of measurements indicated that at working with the chainsaw, hearing protectors have to be used at all three measured distances (close proximity, 5 m from the operator, 10 m from the operator) in order to reduce high noise level as the average noise level was higher than permissible in all measurements. The highest possible tolerable level of acoustic noise (80 dB) at which permanent damage of hearing does not happen was measured at a distance of 21 m from the working place of chainsaw operator. Keywords: chainsaw, Stihl MS 362, vibrations, noise, occupational hygiene, forestry