8
• Voice annotations, using the commentary microphone, are attached to the exact point on
the profile where the annotation is made. With the microphone on an extension cable,
comments can be associated with particular parts of the profile without interfering with the
measurement
All markers and annotations are saved with the measurement, see Fig. 8 and Fig. 9. No further
bookkeeping is required. When exporting data to, for example, 7820 Evaluator software for
further analyses, markers, as well as annotations, are directly accessible on the profile.
Data is stored directly on SD or CF cards. BZ 7224 includes a suitable SD card. Data can be
directly read from the SD card by the included PC software BZ 5503 (see page 11). This
means that even large amounts of data can be quickly transferred to a PC.
In order to give an indication of the amount of memory required, some examples have been
listed below. Values should be compared to the standard size of the SD cards used, which start
at 128 Mbyte.
For convenience, values for 1 s logging periods during 24 h are given. Other values easily
compute from these:
• Five broadband parameters, no statistics: 1 Mbyte
• All broadband parameters, one 100 ms parameter: 3 Mbyte
• All broadband parameters, no statistics: 4 Mbyte
• All broadband parameters, one 100 ms parameter, all 1/3-octave spectra: 30 Mbyte
• All broadband parameters with full statistics: 58 Mbyte
• All broadband parameters, one 100 ms parameter, all 1/3-octave spectra, full statistics:
86 Mbyte
Space needed for annotations and recordings must, of course be added to this. As a guideline,
10 s of voice annotation requires approximately 312 kB.
Enhanced Logging Software – BZ7225
Fig. 9
Display showing part of
a profile with 100 ms
resolution
With the optional Enhanced Logging Software enabled, Type
2250 is optimised for long-term monitoring. It has the func-
tionality of the Logging and Frequency Analysis softwares,
but in addition it will:
• Measure continuously, limited only by data memory and
power supply
• Reboot automatically and resume operation in case of
power failure
• Save data in manageable portions (every 24 hours),
selectable for download
• Make periodic reports, i.e., log all measurement data at a
preset report period
• Let you browse easily between markers (like sound
recordings)
•Measure L
dn
, L
den
, L
day
, L
evening
and L
night
A periodic report is similar to the Measurement Total of the Logging software, except is is
made periodically. It is useful for analysing sound levels over days or weeks. If you combine
periodic reports with level triggered event markers and Sound Recording (option) you have
an overview as well as a focus on essential details.
L
dn
and L
den
are 24 hour, A-weighted equivalent levels specified by the EPA (USA) and the
European Union respectively.
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