14

Suppliers usually report vibration emission data according to harmonised

European standards produced in CEN or adopted from ISO. Examples are listed at

paragraph 37.

15

Where standards specific to a type of tool do not exist, suppliers will use a

general standard method (EN 1033) to determine vibration but it is unlikely that all

suppliers will choose identical operating conditions for the measurements. In such

cases, care is needed to compare the data from different suppliers, particularly if

they have made measurements for different tasks. Manufacturers are obliged to

report the test procedures they have adopted.

16

Some of the early standards have significant shortfalls. For example:

vibration not measured at the handle/grip point producing the highest

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emission (needle scaler and chipping hammer standards);

specified direction of measurement is not the axis of highest magni-

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tude (needle scaler, chipping and grinder standards);

specified or simulated task generates magnitudes below those likely to

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be found in normal use (grinder standards).

17

Test codes are reviewed every 5 years and future versions will provide a

more accurate guide to likely vibration emissions during `intended use'.

18

Vibration emission testing of electrical tools has generally developed

independently of tests for tools using other power sources, eg pneumatic powered

tools. Comparison of vibration emission test data for electric and tools using other

power sources should be made with caution.

19

Suppliers must report the vibration emission from hand-held power tools if it

exceeds a threshold of 2.5m/s2. If it does not exceed 2.5 m/s2, this must be stated.

20

Suppliers should report two values: a and K. The value a is the measured

level and K is the uncertainty. The uncertainty allows for error in measurement or

variation in production and can be more than 40% of the measured emission a and

is often several m/s2. The supplier guarantees that the level determined from a

reproduction of the vibration test used to determine the emission will produce a

measured level with a value less than a + K.

21

The emission level provided by the supplier will often be sufficient to alert the

user to the need to control the vibration risk. Combining a dominant axis emission

level with the duration that the tool is likely to be operated during the day will give a

figure for comparison with HSE's recommended action level of 2.8m/s2 A(8) and