Atec Bruel-Kjaer-2250-2270 - Manual (Page 18)

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Software Specifications – Signal Recording Option BZ-7226
Signal Recording Option BZ-7226 is enabled with a separate license. It
works with all the software for Type 2250/2270: Sound Level Meter,
Frequency Analysis, Logging Software, Enhanced Logging Software and
Reverberation Time Software
For data storage, Signal Recording requires:
• SD Card
• USB Memory Stick
RECORDED SIGNAL
A-, B-, C- or Z-weighted signal from the measurement transducer
AUTOMATIC GAIN CONTROL
The average level of the signal is kept within a 40 dB range, or the gain
can be fixed
SAMPLING RATE AND PRE-RECORDING
The signal is buffered for the pre-recording of the signal. This allows the
beginning of events to be recorded even if they are only detected later.
PLAYBACK
Playback of signal recordings can be listened to using the
earphone/headphones connected to the headphone socket
RECORDING FORMAT
The recording format is 16-bit wave files (extension .wav) attached to the
data in the project, easily played-back afterwards on a PC using
BZ-5503, Type 7820 or 7825. Calibration information is stored in the wav
file, allowing PULSE to analyse the recordings
Functions with BZ-7222 and BZ-7223
Manual Control of Recording: Recording can be manually started and
stopped during a measurement using a pushbutton or an external signal
Automatic Control of Recording: Start of recording when measurement
is started. Minimum and Maximum recording time can be preset
Functions with BZ-7224 and BZ-7225
Manual Control of Recording (using Manual Event or Back-erase
pushbutton, or an external signal): Recording during all of the event,
or for preset minimum and maximum duration. A Sound marker is set
while recording. Selectable pre- and post-recording time
Manual Control of Recording (using touch screen): Recording for the
selected time period (subject to the limitations of the pre-recording
buffer). A Sound marker is set for the selected time period
Automatic Control of Recording: An event can be triggered when a
broadband level is above or below a specified level. Recording during all
of the event or for preset minimum and maximum duration. Selectable
pre- and post-recording time
Functions with BZ-7227
Automatic Control of Recording: Start of recording when measurement
is started
Software Specifications – Tone Assessment Option BZ-7231
LICENSE
Tone Assessment Option BZ-7231 is enabled with a separate license and
can be used with the FFT template (BZ-7230) or with 1/3-octave and
logging template (BZ-7223, BZ-7224 and BZ-7225)
1/3-octave Based Tone Assessment
(with BZ-7223/24/25 Only)
Tone assessment is based on the measured 1/3-octave spectrum in
accordance with either the international ‘ISO 1996:2007 Acoustics –
Description, assessment and measurement of environmental noise – part
2: Determination of environmental noise levels. Annex D (informative)
Objective method for assessing the audibility of tones in noise –
Simplified method’ or the Italian law ‘DM 16-03-1998: Ministero
dell'ambiente, Decreto 16 marzo 1998’
SPECTRA ASSESSED
The displayed 1/3-octave spectrum (L
eq
, L
max
or L
min
) may be assessed.
Assessment is made as post-processing, that is, when measurement is
paused or stopped
SETUP ACCORDING TO STANDARD
Setups in violation of the standard are indicated as such on the display.
You can then accept to apply the default setup. Tone assessment will be
made if possible, in spite of standard violations. For tone assessment
according to ISO 1996-2, Annex D, you can set the division between the
Low and Middle frequency range, the division between the Middle and
High frequency range, and the limits for the level differences between
adjacent bands.
For tone assessment according to DM 16-03-1998, the tones are tested
against loudness contours. Select between ISO 226: 1987 Free-field,
1987 Diffuse-field and 2003 Free-field
RESULTS
Tones are indicated above the spectrum when Tone is selected as
spectrum parameter. The resulting adjustment can be viewed on the
Value panel. It is not saved with the measurement
QUALITY INDICATORS
On the display, a quality indicator (smiley) will indicate that a hint is
available for tone assessment quality. Click on the indicator to see
the hint
Sampling
Rate (kHz)
Maximum
Pre-recording (s)
Sound
Quality
Memory
(KB/s)
8 470 Low 16
16 230 Fair 32
24 150 Medium 48
48 70 High 96