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The effects of vibration on the hand-arm system are measured and evaluated according to ISO 5349, Parts 1 and 2. In accordance with this standard, the vibration is measured at the point where it is transmitted into the hands. In the case of hand-held or hand-guided tools, this point will generally be at the handle. For such tools, the standards for evaluation of vibration exposure provide good guidance for methods of coupling the accelerometer and the measurement point. If the vibration is transmitted through the workpiece or an inserted tool, the measurement standards offer only general advice, because of the wide range of workpieces that might be encountered. Such measurements therefore require a degree of expertise from the person performing the measurement. This is also true for working procedures with very short measuring intervals, several short breaks or frequent movement of the hands or taking the hand off the contact point. This paper reports on hand-arm vibration assessments made on three types of machine: a bone saw, a shoe pounding machine and dental laboratory machines. |