Larson Davis System 824, Справочное руководство

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9/12/00 A -9
13.29 for an exchange rate of 4dB (L
DOD
, or = 4dB/log(2))
16.61 for an exchange rate of 5dB (L
OSHA
, or = 5 dB/log(2))
20.00 for an exchange rate of 6dB (L
Avg
, or Ý 6 dB/log(2)),
n is the total number of samples taken in the measurement;
the sample rate is 32 samples per second,
T
C
is the criterion sound duration as set by the System 824’s
“Criterion Time Hours” setting which by default is set to 8
hours (since the time base for the instrument is 1/32nd sam-
ples per second, the number of hours is multiplied by
115200 to make samples per hour—60 minutes/hour times
60 seconds/minute times 32 samples/sec equals 115200 sam-
ples/second)
L
C
is the criterion sound level as set by the System 824’s
“Overall Criterion” or “Current Criterion” settings
Addition of the term “log(100)” was used to implement the
100 multiplier of the ANSI equation that creates the percent-
age. Subtracting the log of the Criterion Time was used to
implement the division of Criterion Time of the ANSI equa-
tion.
Projected Dose in the analyzers is obtained with an equation
similar to that of Dose except that the actual duration (time)
of the measurement is used rather than a Criterion Time, as
thus:
where the log(n) is the actual time factor, n being the total
number of samples taken.
PROJDOSE 10
log 10
L
s
( )
k
----------
s 1 =
n
∑
 
 
 
 
 
L
C
k
------
n
( )
log 100
( )
log + – –
% =