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Equivalent Noise Levels

The Leq analysis window calculates the Leq values as the analyzer runs.

Leq(t) - the equivalent noise level converted to the user specified "reference time period".  For example, selecting a 3.6 second time segment of 90 dBA noise and specifying a reference time period of 1 hr (3600 sec) produces an equivalent noise level of 60 dBA.  

Leq - the equivalent noise level for the selected time segment.  

Lsel - the equivalent noise level converted to a 1 second period. 

Lpk - the peak level for the selected time segment.  No averaging is used for this parameter.

Lmax - the maximum level for the selected data.  

Lmin - the minimum level for the selected data.  

L10 - the level exceeded 10% of the time.  

L50 - the level exceeded 50% of the time.  

L90 - the level exceeded 90% of the time.  

Click the "Options" button to set the options for these calculations.  You can select the averaging and weighting as needed.  

Calculation Interval:  determines the time period for recomputing the noise values.

Specific Intervals: Leq values will be recalculated at the specified interval

When the Analyzer Stops: Leq values will only be recalculated when the analyzer "Stop" button is pressed.  All data contributes to the Leq values from when the analyzer starts to when it stops. (no values will be available until the analyzer stops).

Channel: Each channel can have different Leq settings.  Use the "Copy settings to all channels" to synchronize the settings for all channels. 

Notes:
The Leq and LeqT values match if the same time sample is used (as well as averaging and weighting).  The LeqT reference time period is set directly in the Leq options dialog box.  The Leq time period equals the time period from when you press the analyzer's Run button to when you press the Stop button.   For example if you set the LeqT reference time to 60 seconds and run the analyzer in the realtime mode for 60 seconds the Leq and LeqT values will be the same (or very close).  The calculation interval allows you to set the time at which the values are calculated and displayed but does not change the Leq time period itself.  As in the above example if you set the calculation interval to 4 seconds you will see the LeqT and Leq values slowly converge as you reach 60 seconds.

The current Calibration settings and Transducer Compensation settings (if enabled) are used for these calculations.

See Also:   Averaging Types,