As an Integrating meter available as either Type 1 or Type 2, the CEL620 has many applications. However, its primary application is for assessing worker noise exposure.
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.
Regulations should also specify whether a Type 2 or the more accurate Type 1 meter should be used. For most occupational noise assessments a Type 2 is usually adequate.
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 CEL620A provides you with the measurement of the average Slow sound level - Lavg. 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 it does not reduce the noise at the ear to an acceptable level then clearly it is not adequate. The CEL620 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. In this case you should go for the CEL620B series meters with real-time octave band filters. 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.
As the CEL620 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 Integrating Sound Level Meter can be bought on its own or as part of a measurement kit.