Svantek SVAN 979, Руководство пользователя

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121
SVAN 979 User Manual
•
Noise Mar.: 10.0 dB
•
Level: 100 dB
2. Place the microphone in one of the selected measurement points (for the
measurement points location see the reverberation time measurement ISO
standard).
Note: The default measurement time of the decay curve registering (Recording Time) is 7 seconds.
It can be insufficient in some applications. It is recommended to set this value to be at least two times
longer than expected reverberation time. For details see Appendix E.
Note: The proper value of the sound level trigger threshold should be set well above the background
noise and significantly below the maximum sound level emitted by the impulse source.
1. Start the measurement process with
the
<Start/Stop> key. The display
indicates that the instrument is waiting
for the trigger condition fulfilment.
2. Fire the impulse sound power source.
If the trigger condition is fulfilled the
instrument starts to collect data.
3. After the data recording process ends,
the instrument starts the calculation of
the reverberation time results. During
this
process, the messages
“Reading Logger…” and
„Calculations…” appear.
4. To save results press the <Save> key
or use the File menu option.
Note: During the data collections in the tested room all other sources of sound should be suppressed
to not affect the measurements.
12.5 V
IEWING OF
RT60
RESULTS
The RT60 measurement results for all 1/1 or 1/3-octave bands and three Total values can be viewed in three
different view modes:
1. Table of EDT , RT20 , RT30 and User results;
2. Bar plot of EDT , RT20 , RT30 and User results;
3. Plot of sound pressure level decay curves.
You may switch between the view modes with the <Alt> and
◄ / ► key pressed together.
Table of RT60 results
The table presents the results of
reverberation time for different RT60 results:
- EDT - early decay time;
- RT20 - reverberation time calculated
with 20 dB dynamics;
►
..
- RT30 - reverberation time calculated with 30 dB dynamics;
-
User - reverberation time, calculated with the user defined dynamics.
Note:
If “- - -” text appears in the RT indicator field, it means that for this band with the selected
parameters (Noise Mar.) the required measurement conditions were not fulfilled to obtain the results
(for more details see Appendix E).