Noise Excitation Equipment for Building Acoustics Measurements

Noise Excitation Equipment for Building Acoustics Measurements
Product Data
Noise Excitation Equipment
for Building Acoustics Measurements
Loudspeaker Systems Nor275 and Nor276
Power Amplifier Nor280
Tapping Machine Nor277
Norsonic is a leading supplier of noise excitation
equipment as well as sound measuring systems
for building acoustics. With more than 40 years
of experience and by carefully listening to our
customer’s requirements we have developed a
complete range of noise excitation equipment.
Besides, fulfilling the technical requirements
set in the ISO140 and ISO3382 standards, our
products is featuring a unique combination of
small dimensions, low weight but yet robust and
easy to use.
A field assessment often requires the equipment to
be carried up several floors. It is therefore important
that the equipment is as small and light weighted as
possible. However, new building constructions often
have a much better sound insulation than previous
constructions. It is therefore important that the emitted
sound power is as high as possible in order to get
a good signal to noise ratio in the receiving room.
These are contrary requirements not easy to achieve
with standard commercial equipment. Norsonic has
therefore designed extremely powerful and lightweighted loudspeakers and a power amplifier with
equalization, ensuring that the power is distributed to
the frequencies that are
The Tapping Machine Nor277 follows the same design philosophy; light weighted, small and robust, with
a weight of only 10 kg including the battery option. It
is the first tapping machine with a build in self calibration test for hammer fall speed and rotational speed.
Innovative sound instrumentation
Noise Excitation Equipment
Features Nor276
• Conforms to ISO 140-3 Annex C standard for airborne laboratory insulation
• Conforms to ISO 3382-2 Annex A 3.1 standard for
reverberation time.
• Conforms to DIN 52210
• Powerful - 120 dB Lw
• Lightweight, portable and rugged design for field
Physical design
Sound power
Using the Nor280 with pink noise, and
120 dB (Lin)
200 WRMS
Peak 1000 W
Dodecahedron Loudspeaker Nor276
A multitude of applications within the field of building
acoustics requires the use of isotropic sound fields. The loudspeaker Nor276 has been designed to comply with these
requirements and satisfies the ISO 140-3 Annex C (Laboratory measurements), ISO 140-4 Annex A (Field measurements) and the ISO 3382-2 Annex A (Reverberation Time
measurements). The output power level is up to 120 dB re. 1pW
for a pink noise signal.
The speaker comes with a tripod ensuring correct
placement so that unwanted reflections and structural
transmissions are kept at a minimum. The rugged cabinet is
made of fibre glass and the speaker elements themselves
are protected by grids to further enhance the concept.
The low weight of less than 9 kg has been obtained by
the use of specially designed loudspeaker elements with
neodyme magnets.
The Nor276 has been designed for continuous operation
for more than one hour at full power. It is designed to
be used with Nor280 Power Amplifier only. Using other
amplifiers may damage the speaker and will void the
355 mm (14”)
<9 kg (19,8 lb)
Tripod mounting
Accessories incl.:
1” diameter
- Speakon NL4FC plug
replaced by a 5m assembled
cable, if ordered with Nor280
- Tripod
The speaker input socket accepts
Speakon NL4FC connectors. A
mounting rod (Ø=1”) makes tripod
mounting easy and safe.
The Nor280 Power Amplifier has
an equalization circuitry matched
to the loudspeakers Nor275
and Nor276, designed to boost
the high and low frequencies to
improve the system performance
when used for building acoustics.
The sound power graph below
includes the sound power
spectrum with the effects of the
equalization circuitry.
Noise Excitation Equipment
Dodecahedron Loudspeaker Nor276 and Power Amplifier Nor276 in situ with a Sound Analyser Nor140 fitted with wireless
Bluetooth module for data transmission between sender and receivers room.
Typical sound power level vs. frequency of the Dodecahedron Loudspeaker Nor276 when used with the pink noise source and
equalizer included in the Power Amplifier Nor280.
Noise Excitation Equipment
100 Hz
315 Hz
1 kHz
3,15 kHz
Sound power in different directions for Nor276. The measurement is done in a horizontal plane through the centre of the loudspeaker. The graph shows the respons for a sinusoidal signal at 100 Hz, 315 Hz, 1 kHz and 3,15 kHz.
Maximum and minimum directivity indices in different directions according to the requirements in ISO 140-3 and ISO
140-4 compared to the tolerance limits.
Maximum and minimum directivity indices in different directions according to the requirements in ISO 3382-1 compared
to the tolerance limits.
Noise Excitation Equipment
Features Nor275
• Nor275 fulfill ISO 140-4 Annex A standard for
airborne insulation measurements in field.
• Powerful - 120 dB Lw
• Lightweight, portable and rugged design for field
Physical design
Hemi-dodecahedron Loudspeaker Nor275
A powerful sound source designed for building acoustics
measurements per ISO-140/4 Annex A (Field measurements).The source provides uniform sound radiation. When
used with the power amplifier Nor280, the high sound
power level ensures accurate descriptors in measurement
conditions that include high background levels, high sound
insulation properties and large room volumes.
Nor275 is designed for placement on the floor and
uses the floor as a mirror for emitted sound.
The loudspeaker is designed to operate at full power
for more than one hour continuously.
The Nor275 is designed to be used with the Nor280
power amplifier only. Using other amplifiers may damage
the speaker and will void the warranty.
Sound power
Using the Nor280 with pink noise,
and equalisation:
120 dB (Lin)
100 WRMS (max)
Peak 500 W
5.3 Ω
355 mm (14”)
195 mm (7.6”)
6 kg (13.2 lb)
Accessories incl.:
- Speakon NL4FC plug replaced
by a 5m assembled cable, if
ordered with Nor280
Typical sound power level vs. frequency of the Hemi-dodecahedron Loudspeaker Nor275 when used with the pink noise
source and equalizer included in the Power Amplifier Nor280.
Noise Excitation Equipment
Power Amplifier Nor280
Our aim is to take the latest technology available to help our
customers complete their measurements faster but without loss of precision. With the Nor280 we have again met
this objective. This power amplifier is the 4th generation of
specially designed units for building acoustic measurements from Norsonic. It is less than half the size and weight,
but twice as powerful as its predecessors; it replaces the
Nor260 as the preferred amplifier to drive the Norsonic
range of full and hemi dodecahedron instrumentation
Unique design
The ISO 140 Building Acoustics Standards place heavy
demands on loudspeakers and as such many may be
destroyed if traditional PA power amplifiers are used to
drive them. These amplifiers are normally very powerful and
designed to give a flat frequency response covering a much
wider frequency range that the speaker system can handle.
Feeding these systems with broadband pink or red/white
noise may destroy the speaker; the low frequency content
of the noise causes the speaker cone to move with much
higher amplitude than its design limits. Hence, the speaker
coil or the cone itself may be destroyed. In addition a lot of
energy is wasted in the low frequency area below 15Hz.
To overcome this problem, and to optimise the power where it is needed, a unique built in equalization network compensates for the falling frequency response of
the speaker system in both the low and high frequency
areas. This also ensures that the 5 dB requirement between
neighbour frequency bands are met when used in combination with the Nor275 or Nor276 loudspeakers. A part of the
equalization network is a high pass filter that removes low
frequency signals that lie below the required frequency range for building acoustic measurements and a low
pass filter that removes all frequencies above 12kHz. This
feature protects the speakers from distortion and concentrates power into the frequency bands where it is needed.
The class D amplifier construction ensures low weight, high
power output and low heat dissipation. The amplifier delivers
up to 500 WRMS into a 4 ohm load and an output current of up
to 35 Amp!
Protection circuits
Both the input and output of the amplifier are short circuit
protected and an automatic system will guard against overheating and too high signal voltage on the input. The built
in cooling fan is normally not running. Only at high room
temperatures or prolonged use of the amplifier at full power
Features Nor280:
• Specially designed for Building Acoustic measurements
• Lightweight and rugged construction
• Self contained noise generator
• 500 Wrms output power
• Emits 120 dB sound power level in the 50—5000
Hz frequency range when used with Norsonic dodecahedron loudspeakers types Nor275 or Nor276
• Wireless remote control of noise generator (optional)
• Equalization network to optimise acoustic output
from speaker
• Balanced signal input for low noise and limited
cross talk problems
• Sound insulation measurements
• Reverberation time measurements
• Absorption coefficient measurements
will the fan switch on. It will however, immediately switch off
when the input signal goes off; this feature makes the unit
well suited to reverberation measurements in areas of low
background noise.
Noise generation
The internal noise generator features both Pink, White
and Red/White noise excitation signals. The noise or line
signal can be attenuated in 5 dB steps to –35dB . By adding
option 1, you may switch on/off the signal remotely and
wireless from another room. The balanced line input
ensures minimum cross talk and induced noise when using
long signal cables.
Noise Excitation Equipment
Short-circuit and over-temperature protected
Output connector:
Speakon NL4MP
Output power:
500 WRMS into 4ohm
250 WRMS into 8ohm
THD+N < 0.1%
The built-in LP and HP filters ensure that the output power matches the Norsonic Nor275 and
Nor276 series of dodecahedron loudspeakers
Peak power:
>1 kWPEAK into 4ohm
Output current:
Maximum 35 A
Balanced input to avoid ground loops and cross talk to signal cables
Input connector:
Input sensitivity:
1.0 VRMS
Input impedance:
10 kΩ//220 pF
(D x W x H)
275 × 110 × 246 [mm]
11 x 4,3 x 9,7 [inch]
3,5 kg
–20 to +35 °C
Rel. Humidity:
Enclosure class:
220 VAC (±10%) or 110 VAC (±10%)
T 3,15A (220 V), T 6A (110 V)
EMC and Safety Standards:
EN55103-1, EN55103-2, IEC61340-5 part 1&2, IEC61010, FCC part 15b part 1&2
Accessories incl.:
Mains cable, Output connector
Ordering info:
Option 1: Wireless on/off remote control (must be specified when ordering)
CE conformity:
EMC compliance according to EN50081-1 and EN50082-1, Safety according to EN61010-11993 and Machine directive 89/392
Optional accessories:
Nor1494/5: Cable (5m) for connecting Nor275 or Nor276 to Power Amplifier Nor280.
Nor1494/01: Opt. 1 : Special length; add/subtract per metre (maximum
length is 25m).
Rugged flight case Nor1327B with room for the Dodecahedron Loudspeaker Nor276, tripod, Power Amplifier Nor280, Sound
Analyser Nor140 and miscellaneous accessories.
Noise Excitation Equipment
Features Nor277:
• Remote operation from hand switch or PC
• Mains or battery operation
• Low weight
• Compact
• Rugged construction
• Built in self check of hammer fall speed, and tapping sequence.
• Retractable feet
Tapping Machine Nor277
The tapping machine Nor277 is the third generation of
tapping machines from Norsonic for performing standardised impact noise tests (foot fall noise). It incorporates all the experience from the former generations into a
compact, light, yet a rugged unit with the construction
based on an extruded aluminium chassis. The hammers
are made of harden stainless steel, ensuring non deformation of the hammer shape even after years in use. The unit
weight is only 10 kg including the optional battery. Retractable feet ensure easy transportation and storage
The unit has the required five hammers each weighting
500g, with a fall height of 40 mm and 100 ms between each
hammer impact. A crystal controlled servo system ensures
the correct tapping frequency is maintained at all times and
temperatures. A level gauge mounted on the top helps the
user to align the unit when adjusting the fall height.
An electronic self calibration test system monitors the
speed of the falling hammers as well as the frequency of
impacts. Errors are indicated on the front by a LED for each
hammer. A gauge is included to facilitate verification of the
fall height. Fall height adjustments are carried out by adjustments of the tapping machine’s three feet.
In its standard version the Nor277 is operated off mains,
but battery operation off an internal battery is available as
an optional extension (Option 1). This optional extension
must be specified on ordering.
Nor277 is equipped with RS232 serial interface for controlling the operation. As an option the unit may be equipped
with a wireless hand-switch for remote start and stop
(Option 2). In this way, the hammer operation can be
switched on and off from the receiving room where the
measuring instrumentation normally is located.
The Tapping Machine Nor277 is a rugged and lightweight construction – the weight is not more than 10 kg –
designed with field applications in mind.
• Impact sound transmission testing according to
ISO140, part VI, VII and VIII, ASTM E-492 and
ASTM E-1007.
5 hammers @ 500 g. Effective falling height
40 mm (adjustable)
10 impacts per second, rpm controlled via
servo feedback loop.
84 – 264 V, 47 – 63 Hz
Optional built-in Li-Ion rechargeable battery.
Battery capacity: Typical 1 hour with intermittent use and 45 minutes of continues
Battery de-rating: <5% loss in capacity per
100 discharge/charge cycles.
Battery charging time: 2 hours
Less than 30 W
H x L x W:
230 x 495 x 165 (265 feet
extended) mm. Add 50 mm to the height
for handle.
10 kg (22 lb) including battery and wireless
remote option
Ordering info:
Option 1: Battery operation, must be specified when ordering
Option 2: Wireless remote control, must be
specified when ordering
Acc. incl.:
Instruction manual, mains cable, small rod
used for the verification of the fall height.
Optional acc.:
Carrying case/Shipping case Nor1336
CE conformity:
EMC compliance according to EN500811 and EN50082-1, Safety according to
EN61010-1-1993 and Machine directive
(Separate Product Data sheet is available)
P.O.Box 24, N-3421 Lierskogen, Norway
Tel.: +47 3285 8900
Fax.: +47 3285 2208
PD NoiseExcit Ed6Rev0 Eng 0713
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