SV 971A User Manual – Appendixes
Peak sound level expressed in dB, for
frequency weightings A, C, Z, symbols
are LApeak, LCpeak and LZpeak. Peak
sound level is calculated for the given T.
( )
=
2
0
2
W
p
tp
maxlog10Peak
T
The highest time weighted sound level
(Max) expressed in dB, within a stated
time interval, for frequency weightings A,
C, Z and time weightings F, S, I symbols
are LAFmax, LASmax, LCFmax,
LCSmax etc.
( )
=
2
0
2
W
p
tp
maxlog10Max
T
The lowest time weighted sound level
(Min) expressed in dB, within a stated
time interval, for frequency weightings A,
C, Z and time weightings F, S, I symbols
are LAFmin, LASmin, LCFmin, LCSmin
etc.
( )
=
2
0
2
W
p
tp
minlog10Min
T
Time weighted sound level expressed at
observation time, expressed in dB, for
frequency weightings A, C, Z and time
weightings F, S, I symbols are LAF, LAS,
LCF, LCS etc.
( )
=
2
0
2
W
p
tp
log10L
Time averaged equivalent continuous
sound level (Leq) expressed in dB, for
frequency weightings A, C, Z symbols are
LAeq, LCeq and LZeq. In principle time
weighting is not involved in a
determination of time averaged sound
level. Time-averaged sound level is
calculated for current time period of the
measurement (T).
( )
( )
=
T
0
2
0
dtptr
T
1
log10Leq
Sound Exposure Level (SEL) expressed
in dB, for frequency weightings A, C, Z,
symbols are LAE, LCE and LZE. SEL is
essentially the subset of the Leq result.
Its value is equal to the Leq result
referred to the integration time equal to
one second (so, for the Integration time
equal to 1 s, SEL is always equal to Leq).
( )
( )
s1
T
log10Leqdtptrlog10SEL
T
0
2
0
+=
=
Only one result from: Lday, Leve, Lnight, Lde, Len, Lnd, and Lden is available in the
instrument. It depends on the day and night time in which the measurement was
performed. Day and night time depend on the <Day Time Limits> option (6h-18h or 7h-
19h).