Larson Davis SoundTrack LxT, Руководство пользователя

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LxT Manual Measurement Settings Tabs
4-9
Ln Tab
Figure 4-8 shows the Ln tab.
FIGURE 4-8 Ln Tab
The Ln value is the measured sound level that exceeds n% of
the measurement time. For example, a value of L
90
= 35 dB
means that the measured sound level is above 35 dB for 90%
of the measurement period. These statistical values are
commonly used to describe the characteristics of non-steady
sound such as environmental noise.
The LxT can calculate six different Ln values based on user-
defined values of n, which can be in the range 00.01 to
99.99%.