Hi, I'm wondering if someone can help me with a few points regarding hand arm vibration readings. Our company uses the Havsense ring style monitor that when used in combination with the software converts the accelerometer readings to HSE points. This week we've had a 45001 auditor within the company and HAVS got brought up. She was happy that we are taking readings but not happy that some of our readings are not a full 8hr shift (or 10-12 if working overtime). My question is can 2 fold. Can the readings be weighted to an 8hr average and if so how is this done in the practical sense? I've had a hunt round the internet but cant seem to get the relevant equations to suit my needs. The reader complies to ISO 8041 so i believe we can use this for our records. In the few months we've used the devices i've only seen 3 readings over 100 and alot are between 30 and 50 points from a user base of about 30 people. Thanks in advance.

I don’t do HAVS bit the lovely Jo who sits next to me does these regularly. She does not measure someone over 8 hours. In a nutshell what she does is take readings for the various pieces of equipment and converts them into a score.  Individuals then filling in weekly cards noting how many minutes they use each piece of equipment for. Jo then can work out what their daily exposure is across all of the pieces of equipment they use. This is my description of what she does, and it is probably only partially correct. The main take away though is you do not need to measure a whole days( 8 hr)  exposure.

Hi Stubbsey

If we take the parallel of noise, as exactly the same principles apply but noise came into greater focus earlier than hand arm vibration.....

For a while when I worked in HSE, I had the grand title of "Nominated Noise Inspector" for the Area.

What this meant was that for a year I had a much more expensive integrating sound level pressure meter than the standard issue meter that every front line Inspector had.

....and I used it a LOT!

But, I never stood in an area for 8 hours.

What I did was take lots of readings in various areas of e.g. factories and asked questions about how long people would be working in those places each day and week.

....and calculated the 8 hour exposure levels on the basis of both the measurements over short durations and the information about how typical that exposure was.

If things were on the balance, then it was time to get the duty holder to invest in personal exposure monitoring. So you put the measuring device on the worker for a full shift and that told the story of how much exposure they were getting at different times of the day AND the overall total over 8 hours (or worked out to 8 hours if they worked more or less than 8 hours).

jendy REPORTED

Thanks for the input. So would i be right in saying for example that i can take one of the employees readings of 45HSE points over 7.5hrs, Divide points by hours giving a single hour average figure, then multiply by 8 to get a full shift reading of 48 HSE points. Because the employees potentialy swap between differing tools during the readings we as a company thought these style of readers would be the best style to wear and compile our data. 

Stubbsey - I'd also check the ring style monitor that is mounted on the hand. How does this comply with ISO5349 for measuring vibration on tool. The standard talks about fixing the traducers firmly attached to the vibration surface, as does L140, and I'm not 100% sure the equipment you've got works to this, albeit I'm happy to be told it does.

These are the readers that we use.

https://havsco.co.uk/dosimeters/

It says on their website that they are compliant. They were purchased before i came into the office some 5 years ago but where never used in anger until came across the devices.

The devices are calibrated annually by the company that supplied them.

As a general rule most employees are quite happy to wear them. Our operations are welding, grinding and fettling of steel fabrications. You don't really have to think about holding onto it because of the added thickness of gloves worn and that the reader is up against the "split" inbetween the two fingers it just stays put. Plus your also gripping the tool at the same time against the post of the meter so vibrations are being transmitted directly into it. 

The hardest think about using the meter in all honestly, is getting the meter back off the employees at the end of the shift.

Its states ISO 5349 which is Measurement and evaluation of human exposure to hand-transmitted vibration. 

BS EN ISO 5349-1:2001 General requirements

BS EN ISO 5349-2:2001+A1:2015 Practical guidance for measurement at the workplace

On the web site they post a CE mark next to ISO 8041:2015 again a two part standard

Part 1: General purpose vibration meters (ISO 8041-1:2017)

Part 2: Personal vibration exposure meters (ISO 8041-2:2021)

On the 2016 data sheet however the CE mark is against measuring equipment standards