LxT Manual
Glossary and Formulas
C
-
11
Eight Hour Time-Weighted
Average Sound Level (L
TWA(8)
)
The constant sound level that would expose a person to the
same Noise Dose as the actual (unsteady) sound levels. The
equation for it is
Lc = Criterion Sound Level
q = Exchange Rate Factor
D = Noise dose in percent
NOTE: This definition applies only for a Criterion Duration
of 8 hours.
Standard
: ANSI S12.19
Equivalent Continuous
Sound Level
The Larson Davis SoundTrack
LxT
calculates equivalent
continuous sound levels based on equations from IEC
standard 61672-1, Section 3.9 which defines Leq as follows:
The LxT displays the equivalent con-
tinuous A-weighted sound pressure
level as
L
Aeq
.
Equivalent continuous A-weighted sound pressure level
(also average A-weighted sound pressure level) is defined as
follows:
where:
L
Aeq
T
is the equivalent continuous A-weighted sound
pressure level re 20 µPa, determined over a time interval T
is a dummy variable of time integration over the averaging
time interval ending at the time of observation t
T is the averaging time interval
L
TWA
8
L
c
qLog
10
D
100
---------
+
=
dB
P
d
P
T
L
L
T
t
A
0
2
/
1
2
AeqT
AT
/
1
lg
20
Summary of Contents for SoundExpert LxT
Page 1: ...LxT Manual for SoundTrack LxT SoundExpert LxT TM...
Page 55: ...4 18 Measurement Settings Tabs LxT Manual...
Page 81: ...5 26 View Spectrum Normalized Optional LxT Manual...
Page 93: ...6 12 Data Storage After Improper Shutdown LxT Manual...
Page 110: ...LxT Manual Certification 7 17...
Page 143: ...11 6 Control Panel Data Explorer LxT Manual...
Page 167: ...12 24 Options LxT Manual...
Page 179: ...14 4 User LxT Manual FIGURE 14 5 shows the User tab FIGURE 14 5 User Tab...
Page 185: ...15 6 File System LxT Manual...
Page 191: ...16 6 Miscellaneous Parameters LxT Manual...
Page 206: ...LxT Manual Technical Specifications A 9 Typical Z Weight Frequency Response...