Results of assessment of sound insulation of TONMAT . roofing sheets

Survey and assess noise levels at some points around the TONMAT roofing sheet in the experimental process manufactured by the Viet Tin Tin Viet Investment and Technology Development Joint Stock Company.

RESULTS OF ASSESSMENT OF THE SOUND INSULATION OF TONMAT
COMPANY MANUFACTURED

Work content:

Survey and assess noise levels at some points around the TONMAT roof sheet sample in the experimental process manufactured by the Viet Tin Tin Viet Investment and Technology Development Joint Stock Company.

Implementation period:  September 20, 2004

Location and environmental conditions:
The experiment was carried out at the Company's production facility at Tien Son Industrial Park, Tien Du district, Bac Ninh province. From 9:00 to 12:00, when taking measurements, the surrounding production activities took place normally.

Equipment used for survey and assessment:

– Equivalent sound level meter NL – 18 class precision type I and 1 Octave Filter NX – 04 of Japan RIon (Precision Integrating Sound Level Meter, Type NL – 18, Class I, and Octave Filter Type NX – 04 , Rion Japan).

– Equivalent sound level meter NL – 01A class II precision class and 1 Octave Filter NX – 01 of Rion Japan (Integrating Sound Level Meter, Type NL – 01A, and Octave Filter Type NX – 01, RionJapan)

Attending staff:

– Mr. Le Xuan Que, Officer

– Ms. Nguyen Quynh Huong, Sound Engineer, Center for Environmental Science and Technology, Research Institute of Labor Protection.

– Mr. Dau Cong Ngoc, staff of Center for Environmental Science and Technology, Research Institute of Labor Protection Science and Technology.

RESULTS OF SURVEY AND ASSESSMENT ARE PRESENTED BELOW

1. Experiment Description:

   – Water sprayer to create rain with a flow rate of 20dm3/min;

   – 3-layer TONMAT roofing sheet, size 5.00m x 1.00m;

   – Measurement points: below the roof of TONMAT at points 0.2m from the roof; 3m; 10m.
   
   2. Calculation value of sound reduction efficiency of PU corrugated iron:  (According to the direction perpendicular to the corrugated board surface).

   Source: Sound level at PU roof with bracket : 81.7 dBA

3. Calculation value of sound level generated by normal and PU sheet: (According to the direction perpendicular to corrugated iron sheet – Roof type ^1000m2 )

COMMENT:

1. The measuring points selected for survey and evaluation include points 0.2m from the experimental corrugated iron sheet below the corrugated iron sheet and 3m, 10m away from the corrugated iron sheet.

2. The average equivalent sound level of the measuring points 0.2m away from the test point; 3m without correction.

3. The average equivalent sound level of measuring points 10m away from the test point can be reduced by 1 dBA after comparing with background noise (According to TCVN 6435: 1998).

4. Comparing PU and ordinary steel, the sound reduction effect is quite obvious (see section 3), especially in the frequency range of 500 - 1000 Hz (reaching from 11 - 15 dB at a distance of 0.2m), is the sensitive frequency range of the human ear.

5. Comparison between PU and normal steel sheet (Section 5) and refer to standard TCVN 5949: 1998 “Acoustics – Noise in public and residential areas. The maximum allowable noise level” shows that the sound reduction effect of PU corrugated iron is quite good: starting from a distance of 20m, the sound level caused by the roof is consistent with area 3 of this standard.

REFER:

1. STANDARD TCVN 6435: 1998. Appendix REMOVE

Table 1. Measurement correction value

2. STANDARD TCVN 5949:1998 “Acoustics – Noise in public and residential areas. Maximum permissible noise level”

   Table 1: Maximum allowable limits for equivalent noise levels in public and residential areas (dBA)
   

KS implementation officer .
Nguyen Quynh Huong