Guide to using HSE hand-arm vibration exposure calculator

• 1. The calculator is a spreadsheet file (Microsoft Excel) which may be downloaded and saved on your computer.
• 2. Click on the white areas and enter a representative vibration magnitude (in m/s2) and an exposure duration (in hours and/or minutes). You can do this for up to six different machines or processes. Information on tool types may be entered directly into the tools/process names columns, or selected from a drop-down list of common tools with HSE's recommended initial value.
• 3. When you have entered all the numbers, press the ENTER key, or click on a different cell. The following values will then be calculated and displayed in the yellow cells on the right:
  • Partial exposure (shown in both m/s2 A(8) and exposure points) for each tool or process, as calculated from the vibration magnitude and the exposure duration.
  • Daily exposure, also in m/s2 A(8) and exposure points, as calculated from the partial exposures.
• 4. In addition to the partial and total exposure values, the calculator also uses the vibration magnitudes to produce the following values:
  • Exposure points per hour. The number of exposure points for every hour of exposure time for the individual machine or process.
  • Time to reach EAV (exposure action value). This is the total exposure time required for the individual machine or process, before the EAV (2.5 m/s2 A(8) or 100 points) is reached.
  • Time to reach ELV (exposure limit value). This is the total exposure time required for the individual machine or process, before the ELV (5 m/s2 A(8) or 400 points) is reached.
• 5. The illustration below shows the calculator in use. In this example, an operator uses three machines during a working day. The vibration magnitudes are 10, 6 and 3.5 m/s2 and the total exposure times are 15, 30 and 90 minutes respectively. For the first tool (a 1" impact wrench), the tool has been selected from the drop-down list, this automatically enters a vibration value of 10 m/s², which is the "recommended initial value" for that tool from the HSE table "summary of vibration magnitudes of some common machines".  For the other tools the values have been typed into the white cells. When entering exposure duration information, you can use hours, minutes or a combination of the two. The results (in the yellow cells) show the partial exposure values for the three machines and the total exposure which is 2.8 m/s2 A(8) or 123 points. Since the result is above the exposure action value a warning is displayed below the daily vibration exposure values.
  
• 6. The cells can be cleared for another calculation by clicking on the Reset Options in the bottom left-hand corner.

Note: When you open the spreadsheet you may see a Microsoft Excel message asking you to decide whether to enable or disable macros. If your system settings allow it, you should enable macros. If not, the Reset button will not work. However, the white cells can still be cleared by deleting the contents manually.