Larson Davis 831, User Manual

Page: 519 / 548

C-6 Basic Integrated Level Calculations Model 831 Manual
L
(s)
is the current SPL at sample s ; for measurements that
include a threshold L(s) is set to × if L(s) is less than the
Threshold Level Lt
k is the exchange rate constant. See the explanation for “q”
on the previous page.
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 831’s
“Criterion Time Hours” setting which by default is set to 8
hours L
c
is the criterion sound level as set by the 831’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
percentage. Subtracting the log of the Criterion Time was
used to implement the division of Criterion Time of the
ANSI equation.
Projected Dose in the analyzer 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:
DOSE 10
10
L
s
 
k
----------
s 1 =
n











L
c
k
-----
T
c
115200
 
100
 
log + log – – log
% =
PROJDOSE 10
log 10
L
s
 
k
----------
s 1 =
n

 
 
 
 
 
L
C
k
------
n
 
log 100
 
log + – –
% =