9/29/09 B-3
though, by placing the weighting designation following the
“dB” units indication associated with the numerical output.
The actual measurement time is also provided for each TWA
value to fulfil the time interval description requirements.
For example, the System 824’s Logging SLM Overall-a dis-
play shows the current SPL (Sound Pressure Level) in 1/
10
th
decibel (dB) resolution. The actual real-time resolution
is 1/32
nd
dB. The displayed SPL is followed by the text
“dB” and then the frequency weighting in effect—set to A in
this example.
The System 824’s Logging SLM Overall-e display shows
the overall measurement period and TWA. In this case the
measurement is L
eq
(because of the 3dB exchange rate).
The quantity is A-weighted and has a measurement elapsed
time of 11:43.1 (11 hours, 43 minutes, and 1 second).
Elapsed measurement time, shown as mm:ss.ss,
hh:mm:ss or hhhhh:mm
Scrolling SPL history
Current SPL while running or at the time a stop
occurred
The currently-selected frequency weighting for
SPL
The currently-selected detector
Elapsed measurement time, shown as mm:ss.ss,
hh:mm:ss or hhhhh:mm
Overall time weighted average (L
eq
in this case)
Time-weighted average (TWA) descriptor for
the overall measurement
Overall sound exposure level (SEL)
Overall exchange rate
To Next Page
Loading...
