Product data

5
Fig. 8
Reverberation time
spectrum (left);
reverberation decay
curve (centre); and
overview of results
(right)
NOTE: A dedicated Reverberation Time Software module (BZ-7227) is also available. Please contact your
Brüel & Kjær representative for details.
Calculations
Standards
Even though the measurement functions (L1, L2, B2, T2) are the same for any building acoustics
measurement, the detailed measurement setup and calculation procedures depend on your national building
regulations. To ensure that your measurements comply, select the relevant standard before you save your first
measurement. This will automatically activate the required setup for measurement and calculation. An
overview of the available standards is shown in Table 1, and the calculated parameters in Table 2 (see page 8).
Results
In addition to measurement data, you may also need the receiving room volume and the partition area for
some calculations. These can of course be entered using the stylus/navigation pushbuttons on the
appropriate instrument display page. You may want to reuse some of your earlier measurements (like a T2
spectrum known from a similar receiving room), to save time. This is also possible, by using a re-use facility
in the Explorer display.
The calculations use a reference curve for frequency weighting of the sound reduction spectrum, resulting in
a single number like R'w = 52 dB (the weighted field sound reduction index according to the ISO 140–4). This
means you will know on site if your construction under test fulfils the minimum requirements of the local
building regulations. Examples of final results are shown in Fig. 9.
Fig. 9
With the required data
measured, final results
are shown, including
the reference curve.
For some results the
volume of the receiving
room and the area of
the partition must be
entered