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Hand-arm vibration exposure A(8) calculator

Daily vibration exposure from tools and trigger times.

e.g. 5:1.5 = 5 m/s² for 1.5 hours

Calculating…

How it's calculated

A(8) = √( Σ aᵢ² × Tᵢ ÷ 8 ) Points = 2 × a² × T (per tool)

Use trigger time only (when the tool is actually vibrating), which is usually much less than time holding it. UK Control of Vibration at Work Regulations 2005: exposure action value 2.5 m/s² A(8) (100 points), exposure limit value 5 m/s² A(8) (400 points).

Use manufacturer declared values with care: in-use vibration is often higher. For guidance only.