Larson Davis SoundAdvisor 831C Reference Manual page 155

FIGURE 18-14 Display Elements On the Live Tonality Tab- ISO1996-2
1.
Tone indicator (green vertical bar); Critical
bandwidth (green horizontal bar)
2.
To navigate from one record to another, press
the left and right buttons (
navigating tones in the graph, press Enter
then press the left and right buttons (
3.
Lpt: Tone Level, Lpn: Noise Level, Lta: Tone
Audibility Level, Kt: Suggested Adjustment Level
4.
To Zoom in or out of the graph use the up and
82
down buttons (
5.
Quality Indicator icons that apply to the
selected tone display here in the bottom left.
When the percent indicator displays, the
graph shows narrow bands of noise that do
not meet the bandwidth requirements in the
Tonality Standard. You can navigate and view
information on these bands just as if they
were "valid" tones.
See Table 18.1 for details on each indicator
including a suggested remedy.
TABLE 18.1 ISO 1996-2: Quality Indicators for Tonality Deficiencies
Icon
The measurement has not been
averaged for at least 1 minute. See ISO
1996-2, section C.2.2
The weighting is set to C. See ISO
1996-2, section C.2.2
The weighting is set to Z. See ISO
1996-2, section C.2.2
The Window is not Hanning. See ISO
1996-2, Note 1
The tone bandwidth is not less than
10 percent of the critical bandwidth.
SoundAdvisor Model 831C
just like the other tabs. The cursor begins on the first valid tone (or the tone at the lowest
frequency). With the cursor over the area, the following details display for each valid tone:
Lpt, Lpn, Lta, Kt, Count. For details on each term, refer to the applicable ISO standard.
46
). To switch to
5
46
).
Deficiency
1.
).
2.
3.
4.
5.
Run the measurement for at least 1 minute.
Change to A-weighting to perform a standard
measurement.
Change to A-weighting to perform a standard
measurement.
Change the Windowing setting to "Hanning"
in the measurement Setup.
Increase the resolution of the measurement
by increasing the number of Lines, or by
decreasing the Frequency Span in the Setup
(FFT tab).
If this icon displays even when the Hanning
window is selected in the Setup, the bands of
noise do not qualify as "tones" in the ISO
1996-2 standard.
Making the FFT Measurement
Remedy
150