Work out vibration exposure (a8) instantly with clear inputs, formula shown and shareable results.
Daily vibration exposure A(8) normalises magnitude to an eight hour reference using the square root of the time ratio, because vibration dose accumulates with the square of magnitude. That relationship is why halving exposure time only reduces A(8) by about thirty percent, while switching to a tool with half the magnitude halves it outright.
Daily exposure
A(8) = a x sqrt(T / 8)
Time to a limit
Hours = 8 x (limit / magnitude)²
Preliminary estimate only. Vibration risk assessment and health surveillance must follow the vibration regulations in force and be carried out by a competent person.
A(8) = a x sqrt(T / 8). Daily vibration exposure A(8) normalises magnitude to an eight hour reference using the square root of the time ratio, because vibration dose accumulates with the square of magnitude.
A better tool. Because A(8) scales linearly with magnitude but only with the square root of time, reducing magnitude gives roughly twice the benefit per unit of change.
This calculator takes 4 inputs: Vibration magnitude, Daily exposure time, Exposure limit value, Exposure action value. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.