Standards Development

Scope

This Technical Specification describes a coupling-force-dependent weighting of the r.m.s. value to the frequency-weighted acceleration ahw.

The procedure only applies to normal gripping situations (embracing a handle). If only part surfaces of the hand are exposed to vibration, the procedure is not applicable.

The evaluation methods defined in this Technical Specification are intended to enable research and should not be used when considering legal duties related to the protection of workers from hand-arm vibration risk in the workplace and the declaration of vibration emissions from machinery.

This Technical Specification provides guidance on an additional procedure to that defined in ISO 5349- 1 for measuring and reporting hand-transmitted vibration exposures by taking into account the coupling force exerted on the vibrating surface.

This Technical Specification is intended to facilitate future research on hand-arm vibration risks. It should be used to supplement the data given by the ISO 5349-1 methodology.

This Technical Specification should not be used as an alternative to ISO 5349-1. The data derived from this Technical Specification should not be used instead of ISO 5349-1 data to perform tasks in accordance with national regulations, guidelines or recommendations for workplace vibration or machinery vibration emissions.

The methodology defined in this Technical Report is based only on biomechanical relationships between vibration transmission to the hand-arm system as a function of total forces. The influence of contact force and pressure on the surface of the hand remains unconsidered and requires further research. 

Purpose

The coupling forces between the hand-arm system and a hand-held or hand-guided machine during its use are very important factors. Although these forces are of interest for both vibrating and non-vibrating machines, the primary focus of this document is to provide a set of descriptions of the forces at the man-machine interface that are primarily for the hand-arm system in contact with a vibrating surface of a machine.

The coupling forces involved in the operation of a vibrating machine generally consist of two different components. The first component is the force applied by the hand-arm system which is used to provide necessary control and guidance of the machine and to achieve desired productivity. This quasi-static force (frequency below 5 Hz) is the focus of this document. The second component is the biodynamic force which results from the biodynamic response of the hand-arm system to a vibration.

This document can assist in the reporting of coupling data in epidemiological or laboratory research. It is expected that in the future, measurements of the coupling forces will be made in addition to measurements at the workplace for the determination and evaluation of human exposure to mechanical vibration.