1 Applicable Scope
The standard specifies the environmental noise limit and the measuring method of Class 5 acoustical environment function zone.
The standard is applicable to the assessment and the management of acoustical environment quality.
The standard is not applicable to the regions at airport periphery due to the noise influence of plane passing (taking off, landing and fly-by).
2. Normative References
The following documents or partial provisions of them are referenced in this standard. For undated references, the effective edition of the normative document referred to apply in the standard.
GB 3785 Electric, Sonic Properties and Measuring Methods for Sound Level Meters
GB/T 15173 Sound Calibrators
GB/T 15190 Technical Specification to Determinate the Suitable Areas for Environmental Noise of Urban Area
GB/T 17181 Integrating-averaging Sound Level Meters
GB/T 50280 Standard for Basic Terminology of Urban Planning
JTG B01 Technical Standard of Highway Engineering
3. Terms and Definitions
This following terms and definitions are applicable to this standard.
3.1 A-weighted sound pressure level
It is referred to the sound pressure level measured through the A-weighting network, and indicated as LA (dB (A)).
3.2 Equivalent continuous A-weighted sound pressure level
It is referred to the average energy value of A-weighted sound pressure level within the specified measured time, indicated by LAeq,T (Leq), and the unit is dB (A). Except the specialized requirements, the noise limits in this standard are referred to the equivalent continuous A-weighted sound pressure level (hereinafter referred to as “equivalent continuous level”).
According to the definition hereof, the equivalent continuous level is calculated according the following formula:
