Room to room Cross-Talk attenuators shall be similar to Q-Tech CT models and shall have the acoustic performance as scheduled. The cross-talk attenuators shall be of a proven design and must have an established history of use. Each unit shall consist of a galvanised sheet metal casing and be provided with internal parallel splitters. The splitter infill material shall be a sound absorbing material as specified by the manufacturer. The infill material shall be covered with a gauze scrim to prevent erosion of the fibres then encased in galvanised perforated sheet metal. The infill material when tested in accordance with AS1530, Part 3, 1989 shall have the following indices:-
Ignitability 0 Spread of flame 0 Heat evolved 0 Smoke developed 0
The contractor shall ensure that an air tight seal is achieved around all wall penetrations to maintain acoustic integrity. Where necessary additional mass lagging shall be applied to the outside of the attenuators to prevent flanking transmission. All units shall have a constant active acoustic length irrespective of grille or section size. Standard units shall have an active length of 900mm and high performance units an active length of 1800mm. Acoustic performance specified is quoted as transmission loss as defined in AS1191:1985.
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