There’s a fair bit of controversy in the world of hand arm vibration measurements regarding where the accelerometer should be located for a powered tool undergoing measurement for a HAV risk assessment. The problem is when the accelerometer is either wrist or glove mounted instead of being mounted firmly and directly on the vibrating surface of the tool, which is what standards BS ENISO 5349 parts 1 & 2 specify.
HSE and Regulatory requirements
The HSE publication HSE -8 Questions about Vibration Exposure Monitoring (paragraph 7) (see http://www.hse.gov.uk/vibration/hav/advicetoemployers/vibration-exposure-monitoring-qa.pdf) states that “Any measurement away from the palm of the hand or where the measurement position is on the back of the hand, fingers or wrist is unlikely to provide reliable measurement. Further advice is given in BS EN ISO 5349-2:2001. There is currently no wrist or glove mounted device which measures vibration suitable for use in a vibration risk assessment...”.
Also, the Control of Vibration at Work (2005) Regulations points to these standards as per the following:
- Under the heading “Vibration measurement and instrumentation” (paragraph 281), it states: “Anyone making hand-arm vibration measurements should be familiar with BS EN ISO 5349-1:2001 and BS EN ISO 5349-2:2002 which contain detailed practical guidance on measurement of vibration in the workplace.”
BS EN ISO 5349- 2 contains the clause: “The accelerometers should be rigidly attached to the vibrating surface”. It is important to note that the action and limit values in the regulations are based upon measurements performed in accordance with these BS EN ISO Standards.
Measurements conducted with accelerometers that are mounted elsewhere other than on the tool’s vibrating surface, or tool handle, could produce significantly different results and therefore affect the outcome of court cases perhaps with expensive consequences.
When carrying out a risk assessment either in house or by hiring external expertise, you should ensure that the assessment be carried out in accordance with BS-EN-ISO 5349 parts 1 and 2 for compliancy against the regulations and make this clear to the assessor.
Further research however, upon alternative methods of hand arm vibration measurement with respect to accelerometer placement should be encouraged as technology advances. If the outcome of such research is accepted by leading experts and recognised organisations that exert influence on the standards and regulatory committees, then the standards and regulations can evolve and therefore be amended accordingly.
Until then you should look to measurements being conducted in accordance with BS EN ISO 5349 parts 1 and 2 standards so that your risk assessments align with the regulatory and HSE requirements.
Essel Acoustics have the expertise, experience and qualifications to carry out hand arm vibration risk assessments with respect to the Control of Vibration at Work Regulations (2005) using the recognised standards.
For further advice please call Satish direct on 07710 356663 or email firstname.lastname@example.org