HJ 706-2014Technical specifications for environmental noise monitoring conrrection for measured noise level (English PDF)

Foreword

To implement the "People's Republic of China Environmental Protection Law" and "People's Republic of China Environmental Noise Pollution Prevention Law" to regulate the environment Monitoring and evaluation of noise emissions from work, the development of this standard.

This standard specifies the method for measuring background noise, noise measurement value correction method.

This standard is developed by the Ministry of Environmental Protection Science, Technology organization.

This standard drafting units. China National Environmental Monitoring Center, Wuhan Environmental Monitoring Center.

This standard MEP October 30, 2014 for approval.

This standard since January 1, 2015 implementation.

The standard explanation by the Ministry of Environmental Protection.

Environmental noise monitoring noise measurement value correction Technical Specifications

1 Scope

This standard specifies the method for measuring background noise, noise measurement value correction method.

This standard applies to amendments to the noise measured value when the monitoring and evaluation of environmental noise.

2 Normative references

The standard content of the following documents cited in the articles. Where undated references, the valid version apply to this standard.

GB/T 8170-2008 revised value represents about rules and limit values and judgment GB 12348 industrial enterprises of environmental noise emission standard plant boundary GB 12523 Construction field boundary environmental noise emission standards GB 12525 railway noise on the boundary and measurement methods GB 22337 social life of environmental noise emission standards

3 Terms and Definitions

The following terms and definitions apply to this standard.

Background noise background noise Environmental noise is emitted from a sound source other than the sum of the measurement noise source.

Noise measurement value measured noise level the measured noise source noise monitoring, measured equivalent sound level or the octave band sound pressure levels. Noise measurement includes Noise measured noise source emissions and other environmental background noise.

Noise measurement value correction for measured noise level Discounting the effect of the noise from background noise measurements to obtain emission values measured noise sources.

Background noise control point the reference point for background noise Different measurement positions measured noise source and measure, from the measured noise sources, sound and other environmental conditions and measuring Consistent background noise measurement point measured the sound source.

4 Background noise measurement method

4.1 Background noise measuring instruments, weather conditions, environmental measurement and the measurement period should follow the GB 12348, GB 12523, GB 12525, GB 22337 and other relevant sources of noise emission standard regulations and requirements.

4.2 Measurement of noise sources should be in the low background noise, more stable when measured as much as possible while avoiding other noise sources. Measuring back Background noise measurements and noise source sound environment as consistent as possible.

4.3 If the measured noise sources can stop the discharge, you should measure before or after the noise source is stopped as soon as the noise source and measure back Background noise. Background noise measurement point and the same noise source measuring point. If the measured noise sources have many monitoring sites, each should be measured Background noise measuring point.

4.4 If the measured noise source within a short time can not stop the discharge, and the period surrounding ambient noise sound source stops around the Issued Changed, you should select a separate agreement with the measured noise source sound environment time measuring background noise. Measuring point with 4.3.

4.5 If the measured noise source is not able to stop the discharge, and the presence of background noise control points, choose the background noise in the background noise According to point measurements. Surrounding the sound source, the measuring point layout and other factors (such as detailed records of background noise should be control points. Green of the belt, topography, sound barriers, etc.), and the measured noise source at the appropriate information and comparison. This method is only background noise and it shall not be used when noise measurement values differ by more than 4.0 dB, a difference of less than 4.0 dB.

5 noise measurement value of the background noise level difference greater than or equal amended by 3dB

5.1 Calculation of noise measured value of the background noise value of the difference (delta L1 = noise measured value - background noise value), rounded to digits.

5.2 difference noise measurement value of the background noise value (delta L1) is greater than 10dB, noise measurement value not corrected.

5.3 noise measurement value of the background noise value of the difference (delta L1) is between 3dB ~ 10dB, according to Table 1 is corrected (noise = Noise emission values measured correction value).

Table 1 3dB<= delta L1<=10dB noise measurement correction table unit. dB

Difference value (delta L1) 3 4 ~ 5 6 ~ 10 Correction value -3 -2 -1 Noise emission values of 5.4 and 5.3 by 5.2 to get the amendment, shall be rounded to the digits.

Compliance determination 6 special circumstances

6.1 For only judge whether the noise source emissions compliance case, if the noise measurement value is lower than the corresponding noise source emission standards limit Value can not be measured and corrected for background noise, indicated after direct evaluation of compliance.

6.2 noise measurement value of the background noise level by less than 3dB, should take measures to reduce the background noise is re-measured after such Background noise measurements and noise values differ more than 3dB, then Section 5 be amended. For still unable to meet the noise measurements Background noise value of the difference (delta L1) is greater than or equal to 3dB requirements, paragraph 6.2.3 to 6.2.1 shall be executed.

6.2.1 Calculation of noise measured value and the measured noise source emission limits of the difference (delta L2 = noise measured value - emission limits), rounded to Digits.

6.2.2 noise measured value and the measured noise source emission limits of the difference (delta L2) is less than or equal to 4dB, given in Table 2 shows Outcomes and to evaluate compliance.

6.2.3 noise measured value and the measured noise source emission limits of the difference (delta L2) is greater than or equal to 5dB, can not love their compliance Condition evaluation, should create the conditions for re-measurement.

Table 2 delta L1 7 octave band sound pressure levels Correction

Correction noise octave band sound pressure level measurements is that background noise spectrum analysis, namely measuring background noise each octave band sound pressure level, depending on the circumstances as described in Section 5 or Section 6 for each octave band measurements corrected or compliance determination, respectively.

8 Numerical rounding rules

According to GB/T 8170-2008 the provisions of value into the house rules.

(1) intends to abandon the left-most digit numbers less than 5, then discarded, leaving the rest of the digits unchanged.

(2) intends to abandon the left-most digit numbers greater than 5, then into a, that is to retain the last digit number plus one.

(3) intends to abandon the left-most digit number is 5, and thereafter there is a non-zero figures into that retain the last digit numbers Word plus one.

(4) intends to abandon the left-most digit number is 5, and thereafter are all non-numeric or 0.00, if the last digit retained Then into a odd, if the last digit retained is even, then discarded.