CESVA SC-30, Руководство пользователя, Страница: 56 / 76

54
•
Be sure that the noise emission of the sound pressure source is stopped.
•
Press to start the measurement process. First it will measure the sound pressure
level corresponding to the background noise L
N
. At the screen it will appear this level for
all octave band (Equivalent level of 1 second in dB).
•
Press to validate this measurement. You will see that these values will stop
oscillating. These values will be taken as the background noise level to calculate the RT.
At the screen it will appear a new column of values that concern to the increase of the
sound pressure level respect the background noise
∆
(in dB).
•
Increase progressively the sound pressure level until you obtain a sound pressure level of
35 dB upper to the background noise for calculating the T
20
and 45 dB upper to the
background noise for calculating the T
30
.
•
When the source is emitting the necessary sound pressure level, you should wait some
seconds to make the acoustic field reach the stationary state.
•
Press to validate this level. You will see that these values will stop oscillating. The
initial maximum levels to calculate the RT will be obtained from these values.
•
From this instant, the SC-30 will wait until you interrupt the noise emission.
•
Stop the noise emission.
•
After a few seconds from the noise emission stop, it will appear at the screen the values of
T
30
and T
20
and the measurement will finish automatically showing up ( ) on the screen.