
9
• All broadband parameters, one 100 ms parameter, all 1/3-octave spectra: 30 Mbyte
• All broadband parameters with full statistics: 51 Mbyte
• All broadband parameters, one 100 ms parameter, all 1/3-octave spectra, full statistics:
80 Mbyte
Space needed for annotations and recordings must, of course be added to this. As a guideline,
10 s of voice annotation requires approx. 312 kB.
If Sound Recording Option BZ 7226 (see following section) is also enabled, Logging Software
BZ 7224 becomes even more versatile. In this case the actual signal can be recorded during,
for example, a noise event. Recordings can be controlled manually, or automatically by a level
trigger. BZ 7226 includes a pre-recording of sound (size of buffer dependent upon sample rate,
see specifications), which means that sound recorded prior to the identification of an event is
also included in the recording. The combination of recording the actual signal and making
voice annotations on a separate channel provides exceptional documentation capabilities.
Sound Recording Option – BZ 7226
Sound Recording BZ 7226 is an option that works with all other software modules. In all cases
it allows you to make recordings of the actual measured signal, that is, the microphone signal
used for measurements (this must not be confused with recorded voice annotations, which
uses the commentary microphone). However, its detailed working is dependent upon which
other software module is enabled and running. In any case, recordings are automatically
attached to the measurement and kept with it, even after transfer of the data to a PC.
The purpose of the Sound Recording Option is to let you record the measurement signal in
order to identify and document sound sources, for example:
• The measured L
Aeq
at 57 dB, did it actually stem from the rather distant compressor, or
from other sources such as nearby birds or traffic? Not necessarily easy to evaluate on-site,
very difficult to document convincingly later. If the signal is recorded: No discussion
• Is it really true that this noise is impulsive and should be penalised accordingly? If the
signal is recorded: There may still be an argument, but it is based on facts
• Exceedances were identified while no operator was present. Did they originate from the
plant under investigation or from another source. If the signal is recorded: No discussion
With Sound Level Meter Software BZ 7222 and Frequency Analysis Software BZ 7223, the
Sound Recording Option BZ 7226 basically lets you do the following:
• Record all or parts of the measured signal giving rise to specific results, levels and spectra
• Set up your instrument so that recording can be set to start automatically when the meas-
urement is started, or you can initiate recordings manually
With Logging Software BZ 7224, additional options are available:
• Recording of sound can be associated with the Event Marker. Use the Event key or set an
Event marker on the profile display: The sound during the event is recorded and attached
to the appropriate part of the profile
• Automatic detection of events – based on level exceedance is also possible, meaning that
recordings can also be initiated when no operator is present
In all of the above cases the maximum duration of recordings can be set (Type 2250 is only
limited by available storage on the memory card currently in use). Recording sound obviously
requires large amounts of storage, therefore Sound Recording Option BZ 7226 allows the user
to decide on the trade-off between storage needed and recording quality (sampling rate).
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