SV 977D User Manual - Appendixes
D.1.2 Definitions and formulas of SLM results
The instrument calculates the sound measurement results for three profiles. The calculation flow diagram for
one profile is presented below:
Percentage of the overloaded input signal, which occurred during the current time period of
the measurement (T)
Peak sound level is calculated for the
given T
(
)
=
2
0
2
W
p
tp
maxlog10Peak
T
Maximal value of the frequency and time-
weighted sound pressure level for the last
second of the measurement
(
)
=
2
0
2
W
1
p
tp
maxlog10Spl
T
Maximal value of the time-weighted
sound pressure level for current time
period of the measurement (T). The Max
result for the 1 second period is equal to
the value of the Spl result
(
)
=
2
0
2
W
p
tp
maxlog10Max
T
Minimal value of the time-weighted sound
pressure level for current time period of
the measurement (T)
( )
=
2
0
2
W
p
tp
minlog10Min
T
Equivalent sound level - time-averaged
sound level for the current time period of
the measurement (T)
( )
( )
=
T
0
2
0
dtptr
T
1
log10Leq
Lmax,
Lmin, Spl,
Ltm3,
Ltm5