As an Integrating, octave band meter available as either Type 1 or Type 2, the CEL620B has many applications. However, its primary application is for assessing worker noise exposure and assessing the suitability of hearing protectors.
Most noise measurement regulations will specify the type and grade of sound level meter that should be used. Some regulations, such as the European noise at work regulations, specify that an Integrating sound level meter should be used. For others, such as the OSHA regulations in the USA, do not demand an Integrating meter, but it makes the measurement process much easier and more reliable.
Most occupational noise regulations state that the sound level meter and calibrator should meet the standards to "Type 2". The CEL620B is also available as Type 1.
The OSHA occupational noise regulations state that you should use at least a Type 2 Sound Level Meter. The meter should be verified by a suitably equipped laboratory when new and we recommend having it checked at least every two years. You also need a Calibrator to check the meter's function before making measurements.
An Integrating meter like the CEL620B provides you with the measurement of the average Slow sound level - Lavg or Leq depending on the regulations you are following. Rather than trying to average the sound level by eye (made more difficult by the logarithmic nature of noise), the meter does the averaging for you. The Lavg is then used to calculate the worker's Time Weighted Average (TWA) noise exposure.
Hearing Protection Assessment
When the noise levels are particularly high (e.g. greater than 95 dBA) then you should check that the hearing protection provided is adequate. If the protection does not reduce the noise at the ear to an acceptable level then clearly it is not adequate. The CEL620B measures both the A and C weighted sound level, so you can use the NRR or HML method.
At higher noise levels or for very tonal noise, it is often better to use the Octave Band method to check hearing protectors. The CEL620B series meters are fitted with real-time octave band filters so you can use the more accurate HML method. For a working example of NRR and HML methods please take a look at our Hearing Protection Calculator.
The web based NoiseMeters Applications includes a section that uses your measurements and calculates the level at the ear when wearing different hearing protectors using the standard NNR method.
As the CEL620B is available as either Type 1 or Type 2 and includes data logging, it is suitable for many environmental noise surveys.
However, we would recommend the CEL633 Environmental Sound Level Meter as this includes additional noise measurement parameters (needed for some regulations, but not all), automatic timer functions and a removable preamplifier (for use in an outdoor kit).
For more information about our environmental noise meters please visit the Environmental Noise page.
The Type 2 sound level meter is available on its own or as part of a Kit, which includes Meter, Calibrator and Carrying Case.