The EU Machinery Directive

European Directive 89/392/EC and subsequent amendments cover vario us aspects of Machinery Safety including noise and vibration. With few exceptions, machinery made or sold in the European Union must now:

Satisfy wide ranging health and safety requirements, for example, on its construction moving parts, stability, noise and, in some cases, its vibration output
In some cases, be subject to type-examination by an approved body
Carry a 'CE marking' and information

The manufacturer must also prepare a technical file relating to the machinery.

In the UK the Directive is implemented in the Supply of Machinery (Safety) Regulations and subsequent amendments (SI 1992-3073 and SI 1994-2063). But the same rules apply throughout the EU and machinery complying with the requirements and tested in one country may be sold anywhere in the EU.

The noise requirements

Machinery must be so designed and constructed that risks resulting from the emission of airborne noise are reduced to the lowest level, taking account of technical progress and of the availability of means to control noise, particularly at source.

Instructions which must accompany all machinery and sales literature must include the following information on airborne noise emission:

The equivalent continuous A-weighted sound pressure level (L_Aeq) at workstations, where this exceeds 70 dB(A); where the level is below 70 dB(A) this must be stated.
The peak C-weighted instantaneous sound pressure (L_pC) at workstations, where this exceeds 63 pascals (130 dB(C))
The A-weighted sound power level (L_WA) emitted by the machinery where the equivalent continuous A-weighted sound pressure level at workstations exceeds 85 dB(A)
For very large machinery, instead of the sound power level, the equivalent continuous A-weighted sound pressure levels at specified positions around the machinery may be given
Where workstations are not defined or cannot be defined, sound pressure levels must be measured at a distance of 1 metre from the surface of the machinery and at a height of 1.6 metres from the floor or access platform. The position and value of the maximum sound pressure must be indicated.

The sound levels must be measured using the most appropriate method for the particular machinery. Test methods and operating conditions must be clearly stated. Test codes are being developed to define standard methods of test and operating conditions for various categories or types of machine.

Where necessary the instructions must specify any particular requirements for installation and assembly for reducing noise and/or vibration (eg the use of dampers, the type and mass of foundation blocks, etc).

The vibration requirements

Machinery must be so designed and constructed that risks resulting from vibrations produced by the machinery are reduced to the lowest level, taking account of technical progress and of the availability of means to reducing vibrations, particularly at source.

If the machinery or equipment is hand-held or hand-guided, vibration measurements must be made in accordance with the appropriate test code, or under stated conditions if no standard test code is available. In the machine's instructions the manufacturer must specify

The weighted rms acceleration value to which the arms are subjected, if it is 2.5 m/s² or more. If the acceleration is less than 2.5 m/s², this must be indicated.
The weighted rms acceleration value to which the body (feet and posterior) is subjected, if it is 0.5 m/s² or more. If the acceleration is less than 0.5 m/s², this must be indicated.

Testing

Some of the test codes require the use of specialist test facilities such as anechoic, semi-anechoic or reverberation chambers. ISVR Consulting can provide such facilities as well as the specialist noise and vibration instrumentation and technical expertise required to measure the sound power, sound pressure and vibration levels required for the manufacturer's technical file. ISVR Consulting can also advise on practical means of reducing machinery noise and vibration at source.

If you require any further information please contact:

Malcolm Smith
ISVR Consulting
University of Southampton
Highfield
Southampton SO17 1BJ
UK

Telephone: 023 8058 2162
Fax: 023 8059 2728

Email: consultancy@isvr.co.uk