Series(s) mHsec app(s) from Type NoiseAdVisor that 3R Brazil Environmental Technology developed to meet you with applications cost affordable, simple, clear and efficient in the area of health and safety (HSE), generating analysis tools, support environmental measurements and performance of hearing protection. It was designed by M.Sc Engineer Rogério Dias Regazzi, chosen and supported by Inova talent´s program from CNPQ / IEL Rio de Janeiro, adding technology, business and professional as Rhuan Barreto developer of this app.

APP DEFINITION:

The "NoiseAdVisor PPE" is extremely easy to use for performance analise of hearing protection in the workplace where the state of the art is applied from the ISO 4869-1, ISO 4869-2 and NIOSH standards. This App is extremely easy to use for performance analise of hearing protection in the workplace where the state of the art is applied from the ISO 4869-1, ISO 4869-2 and NIOSH standards. A practical tool for PPE efficiency required in the lawsuits to prove the adequacy and neutralization of the noise exposure risk in the work environment. A practical tool for analise PPE efficiency.

Approach of the methods:

The HML method specifies three attenuation values, H, M and L, determined from the octave band acoustic attenuation data of a hearing protector. These values, when combined with the noise weighted sound pressure levels C and A, are used to calculate the effective level of A-weighted sound pressure.

The SNR method specifies a single attenuation value, the reduction of single number classification, determined from the octave band acoustic attenuation data of a hearing protector. This value is subtracted from the C-weighted sound pressure level of the noise to calculate the effective level of A-weighted sound pressure. Due to the wide dispersion of the sound attenuation provided by the hearing protectors when used by individual persons, the three methods contemplated in ISO 4869 are almost Equivalent in their accuracy in most noise situations, if we consider the calculations to be 84% reliable. Even the simplest method, the SNR method, will provide a reasonably accurate estimate of the effective A-weighted sound pressure level to aid in the selection and specification of hearing protectors. In the same way as the NRRsf, this being even less accurate of low frequency sources.

In special situations, for example, especially high or low frequency noises, it is necessary to use the HML or octave method. Depending on the choice of a particular parameter in the calculation process, several protection performances can be obtained. This observation is simple, it is enough to look at the EPI efficiency presented in the AC in low, medium and high frequency to verify that the values ​​can be quite different, that is to say, they can provide great attenuations for means sources of noise of medium frequencies and almost no attenuation in sources Of low frequency NPS.

It should be noted that the protective performance values ​​for the three ISO 4869 methods are valid only when: ear protectors are used correctly and in the same way as they were used in the tests when performing the ISO 4869-1 test; The ear protectors are properly maintained in good condition. It should be noted that the anatomical characteristics of the individuals involved in the ISO 4869-1 test are a reasonable combination for the population of actual users. Thus, the main source of potential imprecision in using the three methods described in this part of ISO 4869 is the basic input data of ISO 4869-1.

If the input data do not accurately describe the degree of protection achieved by the target population, no calculation method will provide sufficient accuracy. Differences of 3 dB or less in determining the effective sound pressure level for comparable hearing protectors are generally insignificant. For specific applications, the uncertainty of Annex E of ISO 4869 is recommended.