Sound and Vibration Instrument Hire and Calibration

Norsonic 121 Specifications

The Nor 121 has been withdrawn, most customers prefer the Nor 118+ or Nor 140 or B&K 2250 Real Time Analysers. The following information has been retained for reference purposes.

Nor 121   Dual Channel Multi-function Analyser with one microphone

Nor 121   Dual Channel Multi-function Analyser with two microphones

Overall Accuracy :

IEC 60651 Type 1, IEC 60804 Type 1 - Type 0 with suitable microphones
IEC 61260 class 1 for analogue and digital filters

Analogue Inputs :

No. of channels : 1 or 2 in the building acoustics mode
Microphone input : 7-pin Lemo connectors
Preamplifier voltage : ± 20 V, 3 mA
Polarisation voltage : 0 or 200 V selectable, ± 1%
Maximum input signals: ± 11 V peak
Input impedance : > 1 Mohm // < 200 pF.

Measurement Ranges :

with a microphone. sensitivity of 50 mV/Pa
-10 dB to +137 dB, 140 dB Peak or
0.3 µV to 7 V rms ± 11 V peak

Input Amplifier :

Amplifier gain : 40 dB in 5 dB steps. < 0.2 dB gain error
Additional gain : 0 to 5 dB with an accuracy and resolution of ±0.1 dB for calibration purposes
High pass filters : -3 dB at 0.03 Hz or -3 dB at 16 Hz, Butterworth filter

Self-Noise - Line input :

90 dB FSD
A-weighted : 10 dB
C-weighted : 35 dB
Flat with HP filter on : 37 dB

Self-Noise - Microphone input :

90 dB FSD
A-weighted : 13 dB
C-weighted : 16 dB
Flat with HP filter on : 19 dB

Self-Noise - Line and Mic :

120 dB FSD
A-weighted : 32 dB
C-weighted : 35 dB
Flat with HP filter on : 37 dB

Self-Noise - High dynamic mode :

A-weighted : 14 dB
C-weighted : 17 dB
Flat with HP filter on : 20 dB
Line = noise measured with s/c microphone input connector
Mic. = noise measured with preamplifier and a Nor-1448-18pF microphone equivalent

Analogue Outputs :

AC outputs : 2 x 2.5 mm mono mini-jack connectors.
The output is generated by the DSP. One channel is normally used for AC output, the other channel is normally used for playback of the recorded signal or for voice notes.

optionally it may also be used for generator output

Output level : ± 10 V peak, 1 Vrms corresponds to full scale deflection on display
Output impedance : Max: 10 Ω
Frequency range, AC output : 1 to 20,000 Hz ± 0.5 dB.

Analogue to Digital Converter :

Converter type : Sigma delta with 64 x over-sampling
Sampling rate : 48 kHz
Passband ripple : < 0.1 dB
Stopband attenuation : > 75 dB above 1.3 x cut-off frequency

Digital filters :

6-pole IIR filters for octave and third-octave bands.
The third-octave centre frequencies are set with the factor 10^n/3
Frequency range :

0.125 Hz to 16 kHz for octave bands, centre frequencies

0.1 Hz to 20 kHz for third-octave bands, centre frequencies

Filter response : The octave and third-octave filters meet the requirements of IEC 61260 class 1 and IEC 225 Spectral weighting networks : A : C and Flat.

the Flat spectral weighting network response has a 1st order digital HP filter with fc selectable as 0.1 Hz : 1 Hz : 6.3 Hz or 20 Hz.

Level Detector :

Digital true RMS
Resolution : 0.1 dB
Linearity range : 85 dB or 115 dB with the high dynamic option
Pulse range : 88 dB or 115 dB with the high dynamic option
Level detector accuracy - dual channel :

+5 dB above to 70 dB below FSD : < 0.2 dB

70 dB to 80 dB below FSD : < 0.4 dB

Level detector accuracy - high dynamic option :

+5 dB above, to 90 dB below FSD : < 0.2 dB

90 dB to 110 dB below FSD : < 0.4 dB

Time constants : Fast : Slow : Impulse
Integration period : 5 msec to 200 hours with 5 msec resolution
Crest factor capability : 10 dB crest factor margin at FSD increasing to 90 dB at 80 dB below FSD or 120 dB with the high dynamic option
Overload detector : Latched as well as instantaneous.

Display :

133 x 101 mm STN monochrome, transflective display with switchable back light
Picture resolution : 320 x 240 pixels [h x v] - VGA standard
Displayed range : selectable  20 : 40 : 60 : 80 : 100 dB
Graphical resolution : 0.1 to 0.8 dB depends on selected format
Numeric resolution : 0.1 dB
Numerical range : -99.9 dB to +199.99 dB.

Measurement Storage :

Memory card : PCMCIA type 1 or 2 flash card (4 to 400 MB)
Hard disk : 6 Gbyte.

I/O Digital Interfaces :

RS-232C : 2
Centronics Parallel interface : 1
General I/O Digital Socket : 8 configurable outputs, 4 configurable inputs and external trigger

Signal Generator :

Pseudo-random noise or sine wave
Spectrum types : Pink, octave or third octave noise
Repetition rate : approx. 46 minutes corresponding to 0.00041 Hz spectral line separation
Filters : the octave and third octave filters meet the requirements of IEC 61260 class 1
Noise generator output level : 0 to -40 dB re 1 Vrms in 0.1 dB steps

Power requirements :

11 to 15 VDC, 4 to 10 W depending on measurement task. 40 W peak when charging internal batteries
Batteries : 4 x D-cell type NiMh rechargeable batteries 7.5 Ah
Charger : built-in microprocessor controlled battery monitor and charger.
Charging time 2.5 hours with instrument switched off and 12-14 hours if charging takes place when instrument is switched on
Operating time : typically 12 hours
Warm-up time : <30 sec. for 0.1 dB accuracy

Environmental :

Temperature Range : -10 to +50 °C, gradient 15 °C/hour.
at low temperatures the hard disk requires a warm-up period
Humidity Range : 5 to 95% RH, no condensation
Vibration with HDD running : 5 ms-2, 5-500 Hz sine wave
Vibration with HDD not running : 50 ms-2, 5 to 500 Hz sine wave
Shock with HDD running : 100 G
Shock with HDD not running : 200 G
EMC : in accordance with the EN 50081-1 and EN 50082-1
Safety : in accordance with IEC 61010.
Enclosure class : Ip20.

Dimensions :

with feet
Width : 36 cm
Height : 6.5 cm
Depth : 20 cm
Weight : 2.9 kg with battery
E&OE - specifications subject to change without notice.
* Our standard hire charges are based on a 4-day minimum period, details other options.