How is vibration measured on power tools?

In accordance with EN 60745, sensors are fitted to the handles of the power tools under strictly controlled conditions. The vibration of the power tool is measured in three directions (Tri-Axially) using a special measuring instrument. Tri-axial (in-use) vibration levels are required for proper risk assessment. Single axis levels should not be used without a correction factor, since these are often derived from older test standards e.g. EN 50144 which do not reflect ‘in use’ vibration levels.