HAVex Application Note: The Exposure Points System & Ready Reckoner

Exposure Points System and Ready-Reckoner:


The table below is a ‘ready reckoner’ for calculating daily vibration exposures. All you need is the vibration magnitude (level) and exposure time. The ready-reckoner covers a range of vibration magnitudes up to 40m/s2 and a range of exposure times up to 10 hours.


The exposures for different combinations of vibration magnitude and exposure time are given in exposure points instead of values in m/s2 A(8). You may find the exposure points easier to work with than A(8) values:


·        Exposure points change simply with time; twice the exposure time, twice the number of points


·       Exposure points can be added together, for example, where a worker is exposed to two or more different sources of vibration in a day


·        The exposure action value (2.5m/s2 A(8)) is equal to 100 points


·        The exposure limit value (5m/s2 A(8)) is equal to 400 points

Casella Ready Reckoner for Hand Arm Vibration calculation



1)     Find the vibration magnitude (level) for the tool or process (or the nearest value) on the grey scale on the left of the table


2)     Find the exposure time (or nearest value) on the grey scale across the bottom of the table


3)      Find the value in the table that lines up with the magnitude and time.


4)     Compare the points value with the exposure action and limit values (100 and 400 points respectively)


5)     If a worker is exposed to more than one tool or process during the day, repeat steps 1-3 for each one, add the points and compare the total with the exposure action value (100) and the exposure limit value (400).




The use of hand-held power tools in many industries can result in Hand Arm Vibration Syndrome (HAVS) which is
painful and disabling disorders of the blood vessels, nerves and joints of the hand. The HAVex Tri- Axial hand arm vibration meter allows you to measure the levels of vibration that can be transmitted to the hand from power tools.


The HAVex Tri-Axial Hand Arm Vibration Meter has been specifically designed for Hand Arm Vibration Measurements. It‘s a simple to use meter allowing you measure the levels of vibration that can be transmitted to the hand from power tools.


·        Simple 3 button operation


·        Large dynamic range


·        Easily view, export & report data


·        Includes software

Casella's HAVex for hand arm vibration monitoring

To see prices or further product information for the HAVex, please click here.