Help please, I'm currently trying to work out exposure limits for our employees working with pillar grinders using the HSEs caluculator all was going well until I reached trying to add m/s2. The equipment is old and believe the companies are no longer in business. So I'm unable to find the values for Vibration magnitude. I have worked out the m/s but the m/s2 part is still missing, if anyone can help me with a formula or advise me of some one could help in this matter this would be of great help Out of interest the grinders are: Luke & Spencer 73A24108B CTAA Selson 73A 241 08B CXAA Thank you Brian C

Velocity = acceleration / frequency Regards

Thanks Phil, Will keep you posted and post you formula m/s once I get this problem out of the way Regards Brian (ex 56r Sqn)

I think this has been suitably answered but I would do it like this. 1) use the closest (worst case) equivalent value form the HSE guidance (there is list in here http://www.hse.gov.uk/pubns/indg175.pdf) I also think there is a list in an ACOP somewhere... 2)Then either test the equipment with a HAV meter as suggested or buy a new one as suggest. I would also ensure that in the short term exposure was limited to a duration that was unlikely to present risk from a worst case guestimate. (However this might turn out to be a few minutes a day! And don't forget all the other vibrating stuff they are exposed to) I also am a bit confused as to how you got a value for ms-1 as this is one directional and... hmmm ok its hurting my brain to try and think about the physics....

Brian, i have always found that data supplied by manufacturers never represents real world use, i have also found that different people can use the same equipment with differing results being measured. the condition of the grinding wheel or even a supply from a different manufacturer can also affect your results. i would suggest that you directly measure the vibration a number of times and set your values to overprotect if possible.

Just think of all the useful things you could have bought for £2.99.....................

Hi, Measurement is your best bet, but interestingly, the HSE guidance says you don't have to measure - I think it might even advise you NOT to from memory. I suspect this wouldn't hold much water though when it comes to defending a claim...... Personally, I would steer clear of manufacturers data - I'll stick my neck out and compare it to measuring the weight of an egg on your bathroom scales. A 'middle ground' option is to try to find some existing measured data on one of the excellent Swedish vibration database websites, but this can be hit and miss depending on the machinery you have. If you want me to send you the links, send me a PM. Ta Stu

I knew the Ipod suggestion would get some stick but I'll stand by it in certain circumstances. If you are a consultant selling your services in respect of HAVS / WBV assessments then it is not going to make the grade - you are going to need a callibrated meter with the various clamp attachments. If you are an SME though and cannot source valid data from one of the various databases - like in this case due to the age of the kit, then the Ipod app offers a useful indication. You could use it to compare manufacturers figures against your own readings. You could attach it to the workpiece and check the vibration figure for feeding the workpiece - being careful not to grind it as you suggest Ron. A vibration meter is an accelerometer - the Ipods and Iphones are packed with these so why not use the tech to obtain a guide figure? The only drawback is the awkward shape of the ipod and attaching it to a tool. A workpiece would be easier I suspect. Has to be better than relying purely on manufacturers data, surely?

Stevie, do you have the name of the app, i'd like to take a look at it.

As always, we can debate and agree to disagree! The providers of these apps will freely admit that the techical specification of the ipod accelerometers and gyros in no way correlate with the required frequency response, bandwith filtering or weighting requirements of the ISO standards associated with HAV meters. Same applies to noise - entirely hit or miss. The motion-sensor components in the ipod are provided for gaming purposes. Not knocking the ipod devices, or the users, but in the grand scheme of things, these are essentially adult toys. I had to giggle when someone showed me the spirit-level app! You're right, not everyone can afford to buy HAVS meters. But you can hire them!