We have experienced technicians and all the necessary equipment to perform sound insulation measurement .
Sound Insulation mesurement
To characterize the sound insulation the following indices are used:
– effective sound insulation
– corrected sound insulation
The effective sound insulation D is defined simply as the difference in dB between the level in the emission room, L1, and the level at reception L2 : D = L1- L2.
This difference is given for each frequency band or globally . The ISO standard measurements use a noise (generally pink noise or noise of road traffic) in the emission room. The difference in levels may be given in octave bands or third octave bands, dB or dB(A).
Orders of magnitude:
– 35 dB(A) one can hear everything.
– 40 dB(A) the conversation is unintelligible.
-50 dB(A) the conversation is inaudible.
Corrected Sound Isolation
In some countries, sound insulation corrected between both enclosures DNT takes into account that most of the rooms and dwellings occupied rooms has a reverberation time around 0,5 s. The field measurements are then normalized to this value.
DnT = D + 10 log T/T0,
where T0 is the reference reverberation time 0,5 if T is the measured reverberation time in the receiving space.
In other countries (ex.:Portugal) is used in an equivalent sound absorption area of reference ( often taken equal to 10 m2). We have, in this case:
DnA = D + 10 log A0/A.
We perform tests to check the compliance with the legal requirements in Regulation of Acoustic Requirements for Buildings, approved by the D, L. 129/2002, republished the 9 June 2008 (integrating the changes described in D, L. 96/2008).
Acoustic evaluation tests performed are the following:
- D nT,w - sound insulation index – sound transmited throught the air
- L'nT,w - sound insulation index – percussion sounds
- D 2m,nT,w - sound insulation index – Aerial noise of facades
The Laboratory is accredited by IPAC, according to EN ISO / IEC 17025, for this test.
The standards used are:
Measurement of insulation floor percussion sounds and determination of the sound insulation index – NP EN ISO 140-7:2008, NP EN ISO 717-2:2013, EN ISO 140-14:2004.
Measurement of sound insulation to aerial sounds of facades and facade elements and determination of the sound insulation index – global method with speaker. – NP EN ISO 140-5:2009, NP EN ISO 717-1:2013.
Measurement of sound insulation to aerial sounds of facades and facade elements and determination of the sound insulation index – global method with traffic noise. NP EN ISO 140-5:2009, NP EN ISO 717-1:2013.
Measurement of sound insulation to air sounds between compartments and determination of the sound insulation index – NP EN ISO 140-4:2009, NP EN ISO 717-1:2013, EN ISO 140-14:2004.