Vibration of handheld electric power tools is measured in accordance to EN 60745 series
EN 60745 which measures vibration in three directions (otherwise known as a tri-axial or vector sum measurement). This has been developed to replace the older version of EN 60745 standard and bring the manufacturers vibration measurement procedures in line with the HAV Directive.
In reality there are far too many variables which can affect the outcome of the measurement. The DEWALT view is that job site measurement is too UNRELIABLE. DEWALT recommends that manufacturers values are used for calculating HAV exposure levels providing they are specifically identified as ‘Tri-Axial’ or ‘Estimated Tri-Axial’ according to HSE guidelines and EN 60745-1:2006 and reflect vibration values in the so called upper quartile.