Larson Davis System 824, Руководство по обучению

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2-18 824 Training Manual 3/22/01
Hourly Leq
The Hourly Leq is the equivalent sound level calculated over
an hour period for each hour during the day.
Background Leq
Background Leq can be considered
the Leq expected if the exceedances
had not occurred. The Background Leq is the total hourly energy (hourly Leq)
minus the total energy (event Leq) of any valid event during
that hour.
Hourly Excd Leq
The Hourly Excd Leq is the total energy for all exceedances
that occurred during that one hour period.
Hint:
What happens if there is an exceedance at the change of the hour?
Since most events are rather short in duration, the hour is extended
until the exceedance ends (up to 30 seconds). If after 30 seconds the
exceedance has not ended, the exceedance is split and the new hour
begins. This slight deviation in timing creates no noticeable errors in
data and facilitates the proper calculation of Hourly Background Leq.
Metrics
The Metrics display provides comparative information for
DNL, CNEL, Excd Leq, Bkgd Leq and Leq for the elapsed
time or run time of the instrument.
The data in the Metrics display is
always recorded and saved with the
broadband data. The Metrics display differs from the Daily History in that
the values are integrated over the run time of the instrument
instead of a 24-hour period.