Sound Absorption Measurement 吸聲系數測試

Complied with試驗方法及宣告標準

 

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Sound Absorption Measurement according to ISO 354 [Weighted Sound Absorption Coefficient (aw)]

*

Sound Absorption Measurement for road traffic noise reducing devices, road barrier according to BS EN 1793-1 & 1793-3 (DLa)

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Sound Absorption Measurement according to ASTM C423 (SAA / NRC)

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Field Measurement: Annex X2 of ASTM C423 [Sound Absorption Area (A)]

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根據國家標準 GB/T20247試驗所得的吸聲系數 (as)

 

      Laboratory facility實驗室設施  

Fo Tan Branch 火炭實驗室 (HOKLAS Accredited香港認可處所認可之實驗室)

 

Location:

地點:

About 10-minute's walk from Fo Tan MTR station

由火炭港鐵站步行約10分鐘

Room volume:

測試房容積:

206m3

Test standard:

試驗方法:

ASTM C423 (SAA / NRC)

ISO 354 (aw)

GB/T20247 (aw)

Test Area

測試件所需面積:

ASTM C423

≧6 m2

ISO 354

GB/T20247

≧10m2

 

City University of Hong Kong Branch香港城市大學城市大學實驗室 

(HOKLAS Accredited香港認可處所認可之實驗室)

 

Location:

地點:

Reverberation chamber of the Department of Building and Construction, City University of Hong Kong

香港城市大學

Room volume:

測試房容積:

200m3

Test standard:

試驗方法:

ASTM C423 (SAA / NRC)

Test Area

測試件所需面積:

ASTM C423

≧6 m2

    

     Instrument 測量設備

 

To ensure the highest accuracy and precision of our measurement, our equipment is complied with the requirements of accuracy classes 0 or 1 defined in IEC 651 and IEC 804.

聲壓級測量設備的準確度滿足IEC 651 和 IEC 804中規定的0型或1型准確度要求。  

Equipment
Fulfilled International Standard

Real- Time Frequency Analyzer

Yes

Free- field Microphone

Yes

Microphone Preamplifier

Yes

Sound Level Calibrator

Yes

OmniPower Sound Source

Yes

Test Arrangement 測試安排

 

A band of random noise is used as a test signal and turned on long enough for the sound pressure level in the room to reach a steady state.

When the signal is turn off, the sound pressure level will decrease and the rate of decay may be determined from measurements of the average time for the sound pressure level in a specified frequency band to decay through a certain range.

Repeat the measurement under Empty room and With specimen inside the reverberation chamber condition. Calculate the sound absorption coefficient of the test specimen based in the variation of reverberation time.

分別測量在有和沒有測試件的情況下混響室平均混響時間。

Sound absorption coefficient is given by:

測試件吸音量計算方法如下:

ISO 354 /

GB/T 20247

 &

ASTM C423

 &

 

Standard

試驗方法

A single number descriptor

宣告標準

Calculation

計算方法

ISO 354

Practical Sound Absorption Coefficient (ap)

Arithmetic mean of three 1/3 octave sound absorption coefficients.

Weighted Sound Absorption Coefficient (aw)

A single number frequency-dependent value.

Shape Indicator (L / M / H)

Practical sound absorption coefficient ap exceeds the value of the shifted reference curve by 0.25 or more.

ISO 354,

BS EN 1793-1 & 1793-3

Sound Absorption performance (DLa)

Sound absorption performance expressed as a difference of A-weighted sound pressure levels.

GB/T 20247

Sound Absorption Coefficient (as)

Sound absorption performance

ASTM C423

Noise Reduction Coefficient (NRC)

Average of the sound absorption coefficients of a material for 4 octave bands: 250 Hz, 500 Hz, 1000 Hz and 2000 Hz, inclusive.

Sound Absorption Average (SAA)

Average of the sound absorption coefficients of a material for 12 1/3 octave bands from 200 Hz through 2500 Hz, inclusive.

Certify Your Buildings Specimen 為產品認證

 

Once finished laboratory measurement, a detail report of the measurement, and a Certification that certified the Weighted Sound Absorption Coefficient (aw / DLa ), Noise Reduction Coefficient (NRC) or Sound Absorption Average (SAA) the of the tested buildings specimen will be issued. People can refer to this Certification to consult the acoustics performance of your building products. No more estimation, true data is here.

 

所有的測試件於完成測試後, 均會發出一份具有公信力的測試報告以表示其隔音性能,客戶可以更了解產品的特性。

 

Testing of Absorptive panel

吸音板測試

Testing of Absorptive panel

吸音板測試

Testing of False Ceiling

吸音天花測試

Testing of Absorptive panel

吸音板測試

Testing of Absorptive panel

吸音板測試

Testing of Wedge

吸音物料測試