RESEARCH ON VIBRATION POSES MORE QUESTIONS

Use of the manufacturer data could cause serious underestimates of the risks

HSE has published report by HSL entitled:  RR868 – Evaluation of EN 60745 test codes – BS EN 60745-2-6:2003+A2:2009 concerning the vibration of hand-held electric hammers. The report describes an investigation in to the test code for declaration of vibration emission of electrically powered hammers.

This report concludes: 

“Use of the manufacturers’ data could cause serious underestimates of the risks associated with all uses of these tools and whilst the HSL interpretation of the application of the test code has resulted in emission values that better indicate the vibration risk, the large differences between emission values determined by manufacturers and by HSL have not been explained and suggest a different interpretation or application of the standard test”.

The test code was found to generate repeatable results for hammer-action tools in the tests carried out at HSL. Issues were identified with the properties of concrete that may have influenced repeatability and reproducibility for tools that drill and this is the subject of a further investigation.

Comparing the HSL measured emission data with the vibration magnitudes measured at HSL during typical use showed a reasonable level of agreement.

Comparing manufacturers’ declared emission values to the HSL measured overall field vibration showed that the manufacturers’ a+K emission data reach or exceed the upper quartile of HSL field magnitudes in 27% of cases. Some manufacturers’ data are derived from an earlier version of the test and this accounts in part for the differences, but it does not fully explain the differences.

The HSL interpretation of the application of the test code has resulted in emission values that reach or exceed the upper quartile of HSL field magnitudes in most cases. However, the large differences between HSL measured emission values and those determined by manufacturers have not been explained and suggest differences in interpretation or application of the standard test.