Norsonic nor1216, Instruction Manual

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6 Chapter 4
Technical description
The lower part consists of the base, the microphone
cartridge and the preamplifier Nor1209A. A normal
microphone cable supplied with Norsonic sound level
meters, like Nor1408A, should be used for connec-
tion to the sound level meter instrument. An adaptor
for mounting the outdoor microphone on a tripod is
included.
The base is made of black polyacetal (POM). The
material is durable and insulating, thus preventing
electric noise from ground loops through the mast.
Drops of water from rain are kept away from the
microphone diaphragm by the combined act of the
tubular windscreen, the rain hood and the dust mesh.
The upper part of the microphone cartridge is air- and
water tight, and the backside is vented to the air through
the preamplifier. The electrical power consumption is
increased in the Nor1209A preamplifier compared to
an ordinary Nor1209 preamplifier. This increases the
temperature of the microphone some degrees Celsius
above the ambient temperature and prevents conden-
sation and humidity problems.
The Ingress Protection Category for the assembled
microphone is IP55 according to IEC 60529.
Consider the assembly of microphone,
and preamplifier as a single unit when operated in the
field. If disassembled in the field, the performance
may be reduced due to contamination from dust and
humidity.
When Nor1216 substitute a normal measurement
microphone on a sound level meter, a correction of the
frequency response is normally needed to retain the
class of accuracy for the sound level meter, see Speci-
fications. Based on the correction, the reference direc-
tion may be selected to be either horizontal or verti-
cal. Horizontal reference direction is usually selected
for sound approaching the microphone mainly along
a horizontal axis like noise from industry or vehicles.
A vertical reference axis is usually used for measuring
the noise from aircraft.
The sound analyser Nor140 and Nor150 have cor-
rection network where the reference axis for the out-
door microphone Nor 1216 may be selected to be hori-
zontal or vertical
See separate description in this manual on how to
configure the Nor140 or Nor150.
Electrical description
The power to the Nor1216 will normally be supplied
from a Norsonic sound analyser Nor140 or Nor150
instrument and the user does not need detailed
knowledge of the interconnection. Alternatively, the
microphone unit may be supplied either from a single
supply in the range 28 V to 32 V or a symmetric sup-
ply in the range ±14 V to ±16 V. The latter alternative
is recommended. The connection is shown on the
adjacent figure. (Outside view for the connector).
Rain hood
Microphone
cartridge
Dust mesh
Wind screen