NTi Audio Acoustilyzer AL1 - Manual (Page 32)

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SPL/RTA - Memory Functions
The SPL/RTA mode includes special memory features, such as
SPL/RTA - Sound Level Meter
• LOGGING: records the measured parameters to the internal device
memory every time the log interval ∆t expires (in table form).
SPL/RTA - Real Time Analyzer RTA
• LOAD: loads stored test results into the active AL1 display for
review.
• MATH: completes mathematical averaging of various stored
measurements selected from the memory.
Logging
The Acoustilyzer can record various levels over time into the instrument
memory. e.g. for monitoring sound levels during an event for many hours,.
Every time the recording interval ∆t elapses, the results are stored and
values marked with “_dt” are reset. The logging may stop automatically
after the preset measurement time has elapsed. The results can then
be loaded to a PC and visualized as a level diagram using, for example,
Microsoft Excel.
Note: The stored results remain within the AL1 memory even in the
event of a battery failure during the recording session.
The following parameters are recorded during the logging:
Leq Leq over the whole measurement period. The measurement
period is indicated and controlled by the measurement timer.
PreLeq Leq of the previous measurement timer period (in timer repeat
mode only).
Leq_dt Short time Leq of the actual log interval ∆t . Leq_dt values may
be combined to derive the Leq of any desired period: