mark to the left of the vertical line.

Figure 1

chipping hammer A

rock drill

25 ....................................................................................................................................

20 ....................................................................................................................................

impact drill

15 ....................................................................................................................................

10 ...................................................................................................................................

5 ...................................................................................................................................

range of vibration in intended use

measured emission

mean vibration level in intended use

26

For the impact drill the levels found in `intended' use varied between 5 and 17

m/s with a mean value of just over 10 m/s2. This was represented well by the

supplied level from the standard test for the tool which gave a value of about 12

m/s2.

27

For the chipping hammer the levels found during `intended' use varied

between 10 and 26 m/s2 with a mean of about 16 m/s2. The standard test for the

tool produces a value that lies at the low end of the range of levels measured during

`intended' use but nevertheless gives a clear indication that vibration emission

magnitudes are high and will require management.

28

For the rock drill the level during `intended' use was found to vary between 15

and 25 m/s2 with a mean of about 18 m/s2. The standard test produced a level of

about 12 m/s2 which is below the range of levels measured during `intended use'.

29

Despite the large variations found for each of the tools during `intended' use

and the failure of some of the standard tests to produce values within the range of

levels found during `intended' use, each of the tests produces a vibration emission

level of a high magnitude sufficient to warn of the likely presence of a vibration risk

that will require management. (The similarity of the levels found according to the

standard tests for each of these tools is pure coincidence.)