Nor265 User Guide
6
Norsonic AS
2 Main
application
2.1 Microphone
boom
A number of applications
require measurement of the
spatial average of the sound
pressure level in a room. The
average level may be
obtained by measuring the
level in different positions
and then calculation of the
average level.
N o r 2 6 5
may be used for
moving the microphone from
position to position or the
average may be obtained by
moving the microphone
continuously while
measuring the average sound
level.
Normally the energetic
average is required. This
may be obtained directly by
use of an integrating-
averaging sound level meter
set to indicate the time-
average sound level
L
eq
.
N o r 2 6 5
is normally set up
to produce an oscillating
angular movement
backwards and forwards. The
time for a complete period
may be specified. The
integration time for the
measurement is normally set
to one or a whole number of oscillations.
When delivered, the switch for manual operation is pre-programmed
to default sweeps of ±90° and ±180°, respectively. If
N o r 2 6 5
is
equipped for remote operation (option), the user interface may be used
to re-programme these settings to obtain other sweeps or to obtain
specified positions. The reprogramming of the user interface is most
easily done with the MS Windows program
N o r 1 0 2 9
accompany-
ing the remote operation option. Up to eight positions may be selected
by the switch on the front. The positions may be programmed by use
of the serial interface and will be stored in the internal memory of the
device. Alternatively, the switch may be programmed to contain a
start angle and a fixed step angle. By the use of remote commands and
the accompanying MS Windows program, full control of movements
and positions are obtained.
Average sound level
If
L
i
is the sound pressure level in
microphone position
i =
1...
N
, the
average sound level is calculated
by:
∑
=
=
N
i
N
i
L
L
1
1
10
10
~
Summary of Contents for Nor265
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