NTi Audio Acoustilyzer AL1 - Manual (Page 30)

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TWTD - Time Weighting
Applicable for the actual sound pressure
level measurement. The available response
times, corresponding to IEC 61672, are
• SLOW (long attack and release time)
• FAST (short attack and release time)
The time weighting for the broad band
values ( ) and the RTA view ( ) are
always the same.
HOLD - Cursor Hold
The cursor indicates the band of highest
sound pressure level. For simple readout
and traceability the cursor can remain for
1 - 9 seconds at the frequency band with
the highest level. This may e.g. support
finding of feedback frequencies.
Cursor Readout: Actual level result in the indicated frequency band.
The cursor readout displays the center frequency and the level of the
band pointed to by the arrow. The cursor automatically jumps to the
highest level band in the spectrum.
Alternatively the cursor readout may be controlled manually:
• Select the readout data field and press the enter key.
• A frame flashes around the data readout.
• Move the cursor and read the corresponding test results.
Pause / Reset / Input Range Indicator / TWTD - Time Weighting :
These controls are exactly the same as found on the sound level
meter screen and also effect both, the RTA and the sound level meter
measurement (e.g. pressing PAUSE in the RTA screen also pauses the
broad band Leq, LCpeak and MAX/MIN SPL measurements).
.