To satisfy many occupational noise regulations you need at least a Type 2 Sound Level Meter, along with a Sound Level Calibrator.
When the measured noise level is particularly high, for example greater than 90 to 95 dB(A), it is important that the correct grade of hearing protector is provided. You should not under-protect or over-protect a worker and the best way to assess a hearing protector's performance is to measure the noise levels using an Octave Band Integrating Sound Level Meter. You can then calculate the level at the ear with different protectors, or better still, let some software do it for you.
Following is a basic description of making noise at work measurements using the Model 84 Sound Level Meter with Calibrator:
Before starting a new set of measurements you should check the calibration and operation of the meter using a Calibrator.
The rest is automatic and the meter shows the results of the calibration.
1. Position the microphone
2. Select a suitable measurement range
3. Press the Start key on the meter
4. Wait for the Leq to settle or measure until a representative sample of the noise has been obtained
5. Press the Stop key
You should now note the Leq and Peak readings.
To make an Octave Band noise measurement:
The meter will automatically cycle through all ten octave bands and continue to do this until you press Stop. It is important to run the meter long enough to get a good sample of the noise level in each band.
The results from the octave band measurement can now be used to calculate the level at the ear using different hearing protectors. To reduce the amount of manual calculation involved, the Analyzer software that is included can do all the calculations for you.