Larson Davis 831 - Page 520

Model 831 Manual Basic Integrated Level Calculations C-7
where the log(n) is the actual time factor, n being the total
number of samples taken.
FIGURE C-3 DOSE and Projected DOSE
Sound Exposure Calculations
Sound exposure and sound exposure level are calculated as
specified in IEC 61672-1.
Note that the 831 displays Sound
Exposure as E
X
, where X is the
frequency weighting (X=A, C or Z).
Sound Exposure
See FIGURE C-2 “Sound Exposure
Level and Sound Exposure"
The A-weighted sound exposure E
A
of a specified event is
represented by
where P
A
2
(t) is the square of the A-weighted instantaneous
sound pressure during an integration time starting at t
1
and
ending at t
2
.
The unit of A-weighted sound exposure is pascal-squared
seconds if A-weighted sound pressure is in pascals and
running time is in seconds. However it is sometimes
The currently selected Frequency Weighting (A)
and Detector Response (Slow) for SPL
The currently selected Exchange Rate
Criterion Time and Level
Elapsed measurement time shown as h:mm:ss.s
DOSE
Projected DOSE
dttpE
t
t
A
A
)(
2
1
2

