ISO 717-2:2013 pdf download – Acoustics – Rating of sound insulation in buildings and of building elements
1 Scope
This part of ISO 717:
a) defines single-number quantities for impact sound insulation in buildings and of floors;
b) gives rules for determining these quantities from the results of measurements carried out in one-third-octave bands in accordance with ISO 10140-3 and ISO 140-7, and in octave bands in accord-ance with that option in ISO 140-7 for field measurements only;
c) defines single-number quantities for the impact sound reduction of floor coverings and floating floors calculated from the results of measurements carried out in accordance with ISO 10140-3;
d) specifies a procedure for evaluating the weighted reduction in impact sound pressure level by floor coverings on lightweight floors.
The single-number quantities in accordance with this part of ISO 717 are intended for rating impact sound insulation and for simplifying the formulation of acoustical requirements in building codes. An additional single-number evaluation in steps of 0,1 dB is indicated for the expression of uncertainty (except for spectrum adaptation terms).The required numerical values of the single-number quantities are specified according to varying needs. The rating of results from measurements carried out over an enlarged frequency range is described in Annex A. A method for obtaining single-number quantities for bare heavy floors according to their performance in combination with floor coverings is described in Annex B. An example of the calculation of a single-number quantity is given in Annex C.
4.1 General
The values obtained in accordance with ISO 10140-3 and ISO 140-7 are compared with reference values (see 4.2) at the frequencies of measurement within the range 100 Hz to 3 150 Hz for measurements in one-third-octave bands or 125 Hz to 2 000 Hz for measurements in octave bands. The comparison shall be carried out in accordance with 4.3.
4.2 Reference values
The set of reference values used for comparison with measurement results shall be as given in Table 3. The reference curves are shown in Figures 1 and 2. NOTE The reference values for the octave bands 125 Hz to 1 000 Hz are equivalent to the energetic sum (rounded to integers) of these for the relevant one-third-octave band values. The reference value for the octave band 2 000 Hz has been reduced to take care of the one-third-octave band 3 150 Hz, which (for bare heavy floors) may contribute considerably to the unfavourable deviations.
5.1 General
The reduction of impact sound pressure level (improvement of impact sound insulation), ΔL, of floor coverings when tested on a homogeneous concrete slab floor as described in ISO 10140-1 is independent of the normalized impact sound pressure level of the bare floor, L n,0 . However, the weighted normalized impact sound pressure levels of the floor with and without a floor covering depend to some extent on L n,0 . In order to obtain comparable values for ΔL w between laboratories, it is therefore necessary to relate the measured values of ΔL to a reference floor.