A methodology to measure the acoustic performance of access floors

The European standard EN ISO 140-12:2000 gives a methodology to measure the acoustic performance of access floors in terms of both airborne and impact sound insulation. Access floors are often used in office buildings and working environments as they create a hollow space below the floor surface for network cabling and electrical wiring: in this way they are useful from the functional (ease of inspection, repair and changing of system elements), the aesthetic (no exposed wires and elements) and acoustic point of view. This paper presents the measurement procedures used at the Acoustic Laboratory of the University of Perugia - Italy, in order to perform the tests defined by the EN ISO 140-12. The standard requires the measurement of two parameters, Ln,f e Dn,f , that qualify respectively the airborne and the impact sound insulation trough an access floor, and the calculation of the two corresponding single number indexes Ln,f,W e Dn,f,W. A sample of access floor has been tested in the purposely prepared reverberating rooms of the Laboratory, with and without covering. Particular attention has been paid to test rooms set up and to sample installation because of the complexity of these phases.