Non binding guide to good practice for implementing Directive

E.2 DAILY EXPOSURE: A(8), WHERE THERE IS MORE THAN ONE TASKIf a person is exposed to more than one source ofvibration (perhaps because they use two or more differentmachines or activities during the day) then a partialvibration exposure is calculated from the magnitude andduration for each axis and for each exposure. The partialvibration values are combined to give the overall dailyexposure value, A(8), for that person, for each axis. Thedaily vibration exposure is then the highest of the threesingle axis values.Step 1:Step 2:Determine the three frequency weighted r.m.sacceleration values a wx, a wyand a wz, for eachtask or vehicle, from manufacturer’s data,other sources, or measurement.For each vehicle or task, fi nd the partial dailyexposures in the three directions, x, y and zusing:Step 4:ExampleThe highest value of A x(8), A y(8) and A z(8) isthe daily vibration exposure.A delivery driver spends 1 hour loading his lorryusing a small forklift truck, followed by 6 hoursdriving the delivery lorry each day.Step 1: The vibration values on the seat are:Forklift truck✓ x-axis: 0.5 m/s²✓ y-axis: 0.3 m/s²✓ z-axis: 0.9 m/s²Step 2: The x, y and z axis daily exposuresare then:Forklift truckDelivery lorry✓ x-axis: 0.2 m/s²✓ y-axis: 0.3 m/s²✓ z-axis: 0.3 m/s²PART II Guide to good practice on Whole-Body Vibration – ANNEXES A-HWhereDelivery lorry✓✓T expis the daily duration of exposureto the vibration andT 0is the reference duration of eighthours.Each partial vibration exposure represents the contributionof a particular source of vibration (machine or activity)to the worker’s total daily exposure. Knowledge of thepartial exposure values will help you decide on yourpriorities: the machines or activities or processes with thehighest partial vibration exposure values are those thatshould be given priority for control measures.Step 3: Daily vibration exposure, for eachaxis are:Step 3: For each axis (j), the overall daily vibrationexposure can be calculated from the partialvibration exposure values, using:A j8) = A j1 (8)2 + A j2(8) 2 + A j3(8) 2 + …where A j1(8), A j2(8), A j3(8), etc. are the partial vibrationexposure values for the different vibration sources.Step 4: The driver’s daily whole-body vibrationexposure is the highest axis A(8)value, in this case the value for they or z-axes: 0.4 m/s², i.e. just belowthe exposure action value.93