Sound level meter calibration

[erniemorton]

Is it a Health and Safety requirement to ensure sound level meters used to measure the level in a workplace, factory, shop, etc are calibrated?.
Thanks

[kempie]

The Control of Noise at Work Regulations 2005 require an employer to make sure the legal limits on noise exposure are not exceeded.

http://www.hse.gov.uk/noise/regulations.htm

This is achieved by 'adequate' monitoring. How frequently must a meter be calibrated for it to be described as 'adequate'?

[erniemorton]

Thanks Kempie.

[Hymie]

In answer to Kempie�s question � as to how frequently must a sound meter need to be calibrated for it to be described as adequate, depends to some extent on the noise levels you are measuring.

If for example you are recording levels less than 60dB(A), then you can tolerate a considerable meter error and still be fairly certain that you are well under the limits � and therefore I would suggest you could get away with a calibration period of up to 5 years. If however you are recording values within 5dB(A) or so of the limit, then not only will you need to make more regular measurements to ensure compliance � but should have the meter calibrated on an annual basis.

Some sound pressure meters are supplied with a �calibrated source�, which consists of a small unit which fits over the meter microphone and provides a preset noise level. This is not really a calibration, but a check that the meter is working and giving an output response somewhere close to the expected reading.

The bottom line is that you could be required to defend your sound meter calibration regime (and results recorded) in a court of law � in defense of a damages claim.