Vibration Meters

The Supply of Machinery Safety Regulations 1992 state manufacturers have a duty to provide their customers with information on vibration levels emitted by their equipment which is likely to subject operators to vibration levels (Ah, w) exceeding 2.5 m/s2.

Experience dictates manufacturers data is often compiled from bench test readings taken in factory settings which infrequently mirror actual readings taken on site when the equipment is in use under full load.

Paul Pitts of the HSE’s Noise and Vibration Laboratory has previously commented that "a change is currently taking place, such that dedicated human vibration meters are becoming available; costs of good quality, powerful systems are falling. Vibration measurement is becoming more and more attractive to the non-specialist"

Although it is no longer the domain of the specialist using sophisticated expensive equipment it is highly important only competent persons carry out field testing to ensure accurate interpretation of correct data. (IOSH certification available).

Useful tips if you are contemplating calculating your own vibration measurements

• You should always measure the vibration of the machine running under normal conditions.
• Unless you know the machine well you should always err on the side of caution.
• Equipment which is incorrectly adjusted or badly maintained will produce obscure readings which highlights the need to keep tools sharp and introduce comprehensive maintenance programme's recommended by the manufacturer.
• A lot of people are unsure where they should set their alarm and trip points. This can be critical and where possible this information should be obtained from the manufacturer of the machine being monitored.
• The vibration transmitter should always be mounted as close to the excitation point as possible.
• In order to ensure that the best possible results the instrument should be mounted on a solid part of the handle.
• Using correct lashing methods to secure measuring equipment to tools is crucial to avoid errors and most meter suppliers recommend the use of cable ties as brackets can themselves be subject to resonant vibration.
• A flat clean surface is preferable as mounting on curved surfaces may introduce errors by causing stress on the internal accelerometer.
• Multiple tests are necessary to obtain meaningful readings as the application of tools etc. produces many variants.
• If you find you have a particular vibration control issue you should consult the manufacturer who may consider the possibility of fitting an anti-vibration retro kit.
• Where possible introduce low vibration purchasing policies.

It is essential to thoroughly research the market before selecting a vibration meter. Some popular machine choices used for carrying out independent assessments include l Castlegroup Meters l Larson Davis l EPM Meters l Bruel & Kjaer Meters l Predictec Meters.