Vibration magnitudes of some common Power Tools

Selecting suitable vibration magnitude data

• You should be cautious when identifying vibration magnitude data from which to estimate employee vibration exposures. You need to be careful to select a value that is representative of your work activities and will not produce an underestimate of vibration exposures. Vibration magnitudes associated with machines have changed in recent years (up in some cases, down in others) and you should as far as possible try to obtain up-to-date information. Vibration data is collected for many purposes and is not always suitable for use in estimating daily vibration Vibration data that may not represent the work you are doing includes data measured during non-working conditions such as idling; data used as part of maintenance checks; and data for comparing vibration emissions collected under tightly controlled non-working conditions.

• You can increase your confidence in the quality or relevance of available vibration magnitude information by comparing data from at least two sources and seeking an explanation of any inconsistent vibration magnitudes. Data based on several models of a machine type may be more robust than data for an individual machine model. However, if data from several sources shows that the vibration of a particular model of machine is lower than is generally expected for machines of the same type, using that lower vibration model may reduce vibration

• Many organisations hold information on measured vibration magnitudes, including manufacturers of work equipment, employers, trade associations, government bodies and Vibration data is available through technical and scientific publications and from on-line databases. You may be able to find relevant vibration information from others who have experience with the work processes and machines you use. You are likely to be able to find relevant vibration information for at least your initial assessment of vibration exposures without the need to make measurements yourself.

Making an initial estimate of vibration exposure

You can use the ‘recommended initial value’ vibration magnitudes in Table 1 in combination with your observations of durations of exposure (trigger times) to make an initial estimate of daily vibration exposures. In many cases, this will be sufficient for you to determine your duties under the regulations and to review your control measures and revise them as necessary. The ‘recommended initial value’ is a vibration magnitude that is in the upper part of the range of vibration emissions during normal use of many models of the machine type. The actual vibration exposures may be lower than your estimates. However, vibration magnitudes can be higher than the ‘recommended initial value’ and you should make allowance for this. For example, if your estimated exposures are approaching the EAV you should assume that the EAV is likely to be

Reducing vibration exposure by choosing lower vibration models of machine

For many machines, there is scope for reducing vibration exposures by avoiding high-vibration models of a machine type. There will always be some range in the vibration magnitudes due to differences in the work activity, the operators’ techniques, and the condition of the tool etc. The greater the difference between the ‘Range-lower’ and ‘Range-upper’ values in Table 1, the higher the likelihood that there are clear differences between the vibration hazard of competing models of a machine The wider the range, the more likely it is that there is scope for you to reduce vibration exposure by using vibration magnitude to choose between models of a tool type, for example, using vibration data for real use from reliable sources. Selection on the basis of vibration should be made from a shortlist of tools that have already been shown to be well suited to the work.