- Report #: NT ACOU 069
- Approved: September 1988
This NORDTEST method describes how to determine the sound reduction index of doors in buildings, i.e., in the presence of surrounding party walls whose contribution to the sound transmission may be significant.
This goal is achieved by performing a normal measurement on the complete partition, in its working condition, combined with a measurement on the same partition with an additional insulation applied to the door. The latter test makes it possible to estimate and compensate for the sound transmission via other paths than through the door.
It is assumed that the individual measurements are made according to NT ACOU 027 (IS0 140/IV). The method shall be regarded as a complement to NT ACOU 027 as to the determination of the sound insulation of doors in buildings (see IS0 140/IV, section 3.4).