Larson Davis SoundExpert LxT, Руководство пользователя

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LxT Manual Glossary and Formulas
C
-
3
Criterion Duration (T
c
)
The time required for a constant sound level equal to the
Criterion Level to produce a Noise Dose of 100%. Criterion
Duration is typically 8 hours.
Example : If the Criterion Level = 90 dB and the Criterion
Duration is 8 hours, then a sound level of 90 dB for 8 hours,
will produce a 100% Noise Dose. See Noise Dose.
Standard : ANSI S12.19
Criterion Sound Exposure
(CSE)
The product of the Criterion Duration and the mean square
sound pressure associated with the Criterion Sound Level
when adjusted for the Exchange Rate. It is expressed in
Pascal-squared seconds when the exchange rate is 3 dB.
where q is the Exchange Rate Factor. See Exchange Rate.
L
C
is the Criterion Sound Level.
Standard : ANSI S1.25
Criterion Sound Level (L
c
)
The sound level which if continually applied for the
Criterion Duration will produce a Noise Dose of 100%. The
current OSHA Criterion Sound Level is 90 dB.
Standard : ANSI S12.19
Daily Personal Noise Expo-
sure (
LEP,d
)
It is the level of a constant sound for which exposure over
the Criterion Duration contains the same sound energy as the
actual, unsteady sound over a specific period.
Example : If the Criterion Duration = 8 hours and the specific
period is 4 hours and the average level during the 4 hours is
86 dB, then the L
EP,d
= 83 dB.
Day, Evening, Night Level
(L
den
)
A rating of community noise that differentiates between daytime, evening and nighttime noise
exposure. The equation for day-night level
L
DEN
is:
CSE T
c
10
L
c
q

=