FIELD TEST - ACOUSTIC TEST
OBJECTIVE: Evaluation of building structure performance regarding the standardized facade sound insulation index (D2m,nT,w) in accordance with the limits specified by the standard: DPCM 5/12/1997.
REFERENCE STANDARD: UNI EN ISO 16283; - UNI EN ISO 717-1.
BACKGROUND
The analyzed environments are intended for office use (cat. B) and comparable to commercial activities (cat. G). According to Table B of the DPCM of 5/12/1997, the performance requirement for the standardized facade sound insulation index relative to reverberation time is 42 dB for both cat. B and cat. G.1. Inside the "receiver rooms", background noise and reverberation time (RT60) were recorded; subsequently, the sound insulation of the considered partitions was measured.
EQUIPMENT USED
The measurement chain used for the acoustic testing surveys is as follows:
- one Class 1 sound level meter analyzer, Larson Davis model LxT1L;
- one Class 1 preamplifier;
- one Class 1 free-field microphone;
- one Class 1 sound level meter analyzer, Larson Davis model SoundExpert 821;
- one Class 1 preamplifier;
- one Class 1 free-field microphone;
- omnidirectional acoustic loudspeaker mod. Omni - X4;
- Power-X power amplifier;
- blank pistol;
- laser distance meter;
- tripods;
- windscreens;
- calibrator.
The precision of the Class 1 instrumentation complies with current regulations. The calibration of the LxT sound level meter and the pistonphone complies with the Decree of the Ministry of the Environment of 16/03/1998, art. 2 paragraph 4. The calibration of the SoundExpert 821 sound level meter was performed. The calibration of the instruments was carried out using a Larson Davis CA200 calibrator. The calibration performed before and after each measurement was within ± 0.5 dB. The specifications of the equipment used comply with the requirements of the D.P.C.M. 16/03/98.
SUMMARY OF MEASURED DATA
The following tables show the values obtained from the field measurements of the sound insulation of 7 facades and 3 floor bands (spandrels), along with a comparison against the current limits.
| FACADE TYPE | MEASURED PARAMETER | MEASURED VALUE [dB] | LIMIT | COMPLIANT |
|---|---|---|---|---|
| FT01 – P2 | D2mnitw | 52,0 ± 1 | ≥ 42 | YES |
| FT02 – P3 | 51,0 ± 1 | YES | ||
| FT03 - mezzanino | 49,0 ± 1 | YES | ||
| FT03 – P1 | 51,0 ± 1 | YES | ||
| FT05a - PT | 44,0 ± 1 | YES | ||
| FT08 – P10 | 49,0 ± 1 | YES |
| SOURCE ROOM | RECEIVER ROOM | MEASURED PARAMETER | MEASURED VALUE [dB] | LIMIT | COMPLIANT |
|---|---|---|---|---|---|
| Open space P1 | Open space P2 (FT01) |
R'w | 60,0 ± 1 | ≥ 50 | YES |
| Open space P3 | Open space P2 (FT02) |
61,0 ± 1 | YES | ||
| Open space P1 | Locale piano mezzanino (FT03) | 57,0 ± 1 | YES |
CONCLUSIONS
The post-construction acoustic testing was performed for 6 facades and 3 floor bands (spandrels) of the building with a positive outcome.
