SPL meter

[Harrycr]

Hi
I work in a big engineering company in a office right next to one of the workshops.
We are trying to get the noise level for health and safety reasons.
Are we better off to get a cheap SPL meter and use what weighting A or C or get a microphone and use REW?

Thanks

 

[Wayne A. Pflughaupt]

REW will require you to tote around a laptop to make your measurements, and they will only be accurate with a calibrated USB mic with a sensitivity line to enter into the program.

Typically for noise surveys an environmental company is hired, perhaps with the oversight of an industrial hygienist. Alternately, you could rent a professional-grade SPL meter from an instrument company like Pine Environmental. They have branch offices in much of the country, but if there isn’t one in your locality, there is probably a similar company in operation.

If this is an unofficial operation, then you’re fine with a cheap meter.

Either way, A-weighting is most often used for noise surveys, as it gives preference to the frequencies most likely to cause hearing loss.

Regards,
Wayne

 

[John Mulcahy]

Noise regulations tend to set A-weighted limits, but they are average daily or weekly exposure levels so a cheap SPL meter won't really do the job, you need to log the data for a protracted period. Need either a logging SPL meter or REW, its SPL logger and either a USB mic with a sensitivity figure in its cal file (e.g. UMIK-1) or an analog mic and a separate SPL meter to calibrate its levels.

 

[Wayne A. Pflughaupt]

Clarifying a bit more, if the concern is only for your office, and this is a casual “FYI” exercise, then a cheap meter is adequate, or certainly REW with a calibrated mic if you already have one.

If you’re concerned about regulation compliance, then readings more accurate than you can get with a cheap meter are needed, along with the logger feature John mentioned.

If the workers in the shop are the concern, that is typically monitored by noise dosimeters that selected workers will wear throughout their shift. The dosimeters record sound levels throughout the day, and the information is dumped to a computer that will map the information. Again, this operation is typically planned and supervised by an industrial hygienist.

Regards,
Wayne

 

[Harrycr]

Thank you for your replies.
I have passed this on to the manager.