Svantek SVAN 979, Руководство пользователя

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359
SVAN 979 User Manual - Appendixes
Le Le is calculated for: T
d
= 0, T
e
≠ 0,
T
n
= 0.
( )
( )








+ =

e
T
2
0 W
e
dt p t r
T
1
log 0 1 dB 5 Le
Ln Ln is calculated for: T
d
= 0, T
e
= 0, T
n
≠ 0.
( )
( )








+ =

n
T
2
0 W
n
dt p t r
T
1
log 0 1 dB 10 Ln
Lde Lde is calculated for: T
d
≠ 0,
T
e
≠ 0,
T
n
= 0.
( )




 + 
+
=
10 Le 10 Ld
10 4 10 12
4 12
1
log 10 Lde
Len Len is calculated for: T
d
= 0, T
e
≠ 0,
T
n
≠ 0.
( )




 + 
+
=
10 Ln 10 Le
10 8 10 4
8 4
1
log 10 Len
Lnd Lnd is calculated for: T
d
≠ 0,
T
e
= 0, T
n
≠ 0. ( )




 + 
+
=
10 Ld 10 Ln
10 12 10 8
12 8
1
log 10 Lnd
Lden Lden is calculated for: T
d
≠ 0,
T
e
≠ 0,
T
n
≠ 0. ( )




 +  + 
+ +
=
10 Ln 10 Le 10 Ld
10 8 10 4 10 12
4 8 12
1
log 10 Lden
EX Expected value. Calculated on the basis of
100ms RMS results.
SD Standard deviation. Calculated on the basis of
100ms RMS results.
NR
Noise Rating, measured noise level that takes
into account the frequency content of the noise.
NR is calculated if 1/1 Octave function is active.
To calculate the NR value, the noise level in
each 1/1 octave band (from 31.5Hz to 8kHz)
is compared to the “NR curves” for each
corresponding band. The NR curve number
which applies to each frequency band is the
highest numerical value that is not exceeded
in that band. The overall NR value is the
highest of the individual NR values for the
frequency bands.
NC
Noise Criterion, measured noise level that takes
into account the frequency content of the noise.
NC is calculated if 1/1 Octave function is active.
To calculate the NC value, the noise level in
each 1/1 octave band (from 63Hz to 8kHz) is
compared to the “NC curves” for each
corresponding band. The NC curve number
which applies to each frequency band is the
lowest numerical value that is not exceeded
by
each individual frequency band. The
overall NC value is the highest of the
individual NC values for the frequency
bands.