The sound-interception coefficient which shows degree of interception of sound means it reveals coefficient of correlation of reverberation hour which is used for passing through the sample with the remainder sound wave in air in the reverberation room.
 
NGC Testing Services Acoustical Testing Laboratory

CAC by ASTM E 1414-97
(Foot notes : CAC = Ceiling Attenuation Class)
 
   
Examination date : 2001.10.03
Examination material : JEIL PLANK CEILING (STL 0.7T, 300mm X 1200mm, powder coating (0.06T)) w / Acoustic fabric(0.2T), glass fiber(30T), Gypsum board(9T)
Examination condition : Temperature 20.1กษ, Relative humidity 61%
Examination result : CAC = 52dB

 

 
 
   
Examination date : 2001.10.03
Examination material : JEIL PLANK CEILING (STL 0.7T, 300mm X 1200mm, powder coating (0.06T)) w / Acoustic fabric(0.2T), glass fiber(30T), Gypsum board(9T)
Examination condition : Temperature 19.3กษ, Relative humidity 59%
Examination result : CAC = 48dB

 

 
   
Examination date : 2001.10.03
Examination material : JEIL PLANK CEILING (STL 0.7T, 300mm X 1200mm, powder coating (0.06T)) w / Acoustic fabric(0.2T), glass fiber(30T)
Examination condition : Temperature 20.8กษ, Relative humidity 65%
Examination result : CAC = 26dB

 

 
   
Examination date : 2001.10.03
Examination material : JEIL PLANK CEILING (STL 0.7T, 300mm X 1200mm, powder coating (0.06T)) w / Acoustic fabric(0.2T), glass fiber(30T), Gypsum board(9T)
Examination condition : Temperature 19.4กษ, Relative humidity 59%
Examination result : CAC = 48dB

 

 
   
Examination date : 2001.10.02
Examination material : JEIL PLANK CEILING (STL 0.7T, 300mm X 1200mm, powder coating (0.06T)) w / Acoustic fabric(0.2T), glass fiber(30T), Steel sheet(0.6T)
Examination condition : Temperature 20.8กษ, Relative humidity 58%
Examination result : CAC = 46dB