SV 104 USER'S MANUAL_
DRAFT
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25
3.9.4
OCTAVE analysis spectrum view mode
The instrument operates as a real time 1/1 octave band analyser (RTA). In addition and if enabled, 1/1
octave analysis is performed in parallel with the dose meter operations. All 1/1-octave digital pass-band
filters (with 9 centre frequencies from 8 kHz down to 31.5 Hz; in base two system) are working in real-time
with the broadband frequency weighting filters (Z, A or C) and the linear LEQ (LEQ) detector. This enables
the user to pre-weight a spectrum with one of the selected broadband frequency curves if required for a
particular application such as the provision of hearing protectors in the control of high workplace noise levels.
Notice:
The three overall TOTAL LEQ results are measured with the weighting filters (A, C,
Z) without taking into account the settings of the level meters for profiles. The spectra are always linearly
averaged. Thus, the TOTAL values from 1/1 octave band analysis can be different from those obtained for
the profiles (if the LEQ Integration was set as Exponential).
The results of 1/1 Octave analysis (so-called spectrum) can be examined by the user on a display
in Spectrum VIEW presentation mode. 1/1 Octave spectra for all 9 centre frequencies of pass-band filters
together with the 3 TOTAL overall values measured with the user selected frequency weighting filters
are presented in the Spectrum mode if enabled in configuration setup. Spectrum cursor can be moved left
and right with
<SCROLL>
,
<PROFILE>
keys respectively.
Figure 3-13
Octave analysis spectrum graph LEQ view mode screens
Figure 3-14
Octave analysis spectrum graph MAX view mode screens
current
centre
frequency
current
Total LEQ
weighting filter
value of the
spectrum
at cursor
position
weighting
filter
cursor
current
centre
frequency
current
Total Lmax
weighting filter
value of the
spectrum
at cursor
position
weighting
filter
cursor