Johns Manville Acoustical Laboratory

Abstract

Due to their long history in acoustics materials, the Johns Manville Corporation has maintained an acoustical laboratory in constant operation since the 1930s. The laboratory complex is accredited under NVLAP for a broad range of ASTM and ISO test methods. For classic architectural acoustics evaluation, the lab has a reverberant test suite with a 142-m3 source chamber and a 316-m3 receive chamber. The chambers’ common opening allows for 2.8 by 4.3-m samples and is qualified from 100–10<th>000 Hz. Analysis of complex, three-dimensional systems conducted in a 176-m3 hemi-anechoic chamber qualified to 160 Hz. Both intensity and pressure measurements are possible via a 5 degree-of-freedom robotic positioning system. Research of open office acoustics and office furniture is performed in a 111- (to the grid, 142 total) m3 chamber designed to accept a suspended ceiling and vary its reverberation time from <0.3 to 2.3 s. In addition to these facilities, several benchtop and analytical resources are available.