User manual

49
Sound Level Meter
Events (optional)
The event function is available with the XL2 Extended Acoustic
Pack Option. The XL2 Analyzer may be configured to record
wav-files and additional noise levels only when triggered, in-
stead of the complete measurement duration.
Advantages
Reduces the data volume acquired, thereby
Simplifying data post-processing•
Saving memory for long-term measurement applications.•
Events
Events are triggered either automatically by sound levels above/
below a preset value or manually by external key press using
the XL2 Input Keypad.
Data Logging
The XL2 Analyzer logs the data specified in the
LOG setting for the complete measurement du-
ration into a log file. The markers and triggered
events results are added to the same log file.
The XL2 Input Keypad is available as an acces-
sory. Please see chapter Options and Accesso-
ries for details.
Recommendation
With the large storage capacity of the XL2, NTi Audio recom-
mends logging at a 1 second or faster interval. This allows the
accurate collection of event data; one event will be stored with-
in a logged interval. If results for reporting are required at lon-
ger intervals, e.g. one hour, the XL2 Data Explorer software is
recommended. It easily combines logged data into longer audit
intervals. An additional advantage of a faster logging interval is
that only an entire logged interval can be excluded from the
average. This is useful when a qualified noise consultant judges
that a sound is not caused by the object under test or is not a
normal sound for a measurement location.
Functions
The XL2 event feature offers the following functionalities:
Automated event triggered at noise levels above/below a •
preset value including setting markers for specific noise cat-
egories. Application example: Recording the noise level for
L
AF
> 80 dB.
Event triggered by external key press of the XL2 Input Key-•
pad. You can utilize four keys (1-4) to categorize any noise of
interest or noise to be later excluded in the post-processing.
A typical application is categorizing any annoying industrial
noise by persons living in the neighborhood.