Percentile Levels - CESVA SC310 User Manual

p(t):
p :
0
T:
T :
0
Its relation with the equivalent continuous level is the following one:

6.2.6 Percentile levels

L , L , L , L
99 95 90 50
L , L and L These are the levels that were exceeded during 99%, 95%, 90%, 50%, 10%,
10 5 1
5% and 1% of the analysis time, in decibels.
In Sound Level Meter mode they are calculated with classes of 0.1 dB using
the function L
classes of 0.5 dB and using the function L
In some English speaking countries, the percentile levels are known as the
exceedence levels, or the statistical levels, or simply as L
number from 0.1 to 99.9.
⎛
T
2
1 p (t)
⎜ ∫
= ⋅
L 10 log
⎜
E
T
p
⎝
0
0 0
instantaneous sound pressure
reference sound pressure (20 µPa)
duration of the measurement
1 second
= − ⋅
L L 10 log
t E
. In the 1/1 spectrum analyser mode they are calculated with
AF
⎞
⎟
dt
⎟
2
⎠
⎛ ⎞
t
⎜ ⎜ ⎟ ⎟
T
⎝ ⎠
0
.
AT
76
values, where 'n' is a
n