USING ISO 2631-5 AS AN ADDITIONAL WHOLE BODY VIBRATION EVALUATION METHOD WITH ISO 2631-1 TO INCLUDE ALSO TRANSIENT SHOCKS TO THE ANALYSIS

摘要

The European Union Physical Agents Directive (vibration) sets vibration exposure limits for an employer. The directive refers to ISO 2631-1 (1997) on how to measure and analyze the whole body vibration. However ISO 2631-1 takes poorly into account transient shocks, especially those which occur rarely. Still the transient shocks are recognized to be dangerous to a lumbar spine, even though they would occur rarely. The directive instructs to do a risk assessment also to the repeated shocks. Partly for this reason ISO 2631-5 (2004) was produced. The standard has a method on how to analyze the effect of transient shocks based on an experimental model of the lumbar spine response. Using the method one can calculate the pressure that a shock or multiple shocks will create to the spine and thus analyze if it will be damaged or not. Although the directive does not refer to ISO 2631-5 it is the only current standard that can be used to analyze shocks properly. In this study ISO 2631-5 was used as an additional evaluation method to determine how helpful it is and what kind of implications it has. The study used whole body vibration measurements from 26 mobile work machines that were previously analyzed only using RMS values based on ISO 2631-1. The results showed that ISO 2631-5 is useful especially when the result values are showed jointly with ISO 2631-1 RMS values. From RMS value alone it is very hard to conclude what kind of characteristics the vibration has. With the acceleration dose or static compressive stress value from ISO 2631-5 also shown the results will be easier to evaluate.