Larson Davis SoundTrack LxT, Руководство пользователя

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LxT Manual Glossary and Formulas
C
-
1
A P P E N D I X
C
Glossary and Formulas
This appendix contains technical definitions of key
acoustical and vibration terms and formulas commonly used
with Larson Davis instruments. Refer to American National
Standards Institute document S1.1-1994 for additional
definitions. Specific use of the terms defined are in the main
body of the text.
Allowed Exposure Time (T
i
)
The allowed time of exposure to sound of a constant level
given a Criterion Level, Criterion Duration, and Exchange
Rate.
where L
c
is the Criterion Sound Level, T
c
is the Criterion
Duration, Q is the Exchange Rate, K is the Exchange Rate
Factor and L
avg
is the Average Sound Level.
E xample : If L
c
= 90, T
c
= 8, Q = 3 and L
avg
= 95 then
This means that if a person is exposed for 5 hours and 39
minutes he will have accumulated a Noise Dose of 100%.
Standard : ANSI S12.19
Ti
Tc
Lavg Lc –
 
Q

2
-----------------------------------------
Tc
Lavg
L
c
–
 
q

10
-----------------------------------------
= =
T
i
8
10
95 90 –
 
10

-------------------------------
8
2
95 90 –
 
3

--------------------------
5.656 = 5 hours and 39 minutes = = =