Manufacturers' Specifications

Norsonic 840

Analogue Inputs :   dual channel analyser
Microphone inputs (2) : 7-pin LEMO connectors are standard
• preamplifier voltage : 120 V, 3 mA to each preamplifier
• polarisation voltage : 0, 28 or 200 V selectable, ± 1%
Direct inputs (2) : BNC connectors
Charge inputs (2) : TNC connectors
Intensity Input : 18-pin LEMO connector
Maximum input signals : 120 V PEAK, Line and Mic. inputs
Input impedance : 1 MΩ / 120pF, all inputs

Input Amplifiers :
Amplifier gain : -40 dB to +70 dB in 5 dB steps
• additional gain : 0 to 10 dB with accuracy and resolution < 0.1 dB for calibration purposes
Measurement range : 0.03 µV - 31.6 Vrms.
• corresponds to SPL values from -20 dB to +150 dB with a microphone sensitivity of 50 mV/Pa
Amplification error : Better than 0.2 dB : 20 Hz - 12.5 kHz

Frequency range - AC output :
• 0.1 Hz to 100 kHz with ± 0.5 dB
• 0.05 Hz to 200 kHz with ± 3 dB
High-Pass filters : 3-pole Butterworth selectable at 0.63 Hz or 20 Hz, all inputs
Low-Pass filter : 3-pole Butterworth selectable at 2 kHz, charge inputs only
Hum and Noise :
• Mic. Input : 10 dBA : 15 dB Lin
• Line input : 0 dBA : 3 dB Lin, measured with preamp. and dummy microphone

Analogue Outputs :
Wideband outputs - 2 : BNC connectors. The output signal comes directly from the input amplifiers
Output impedance : Max. 10 Ω
Output level : ± 10 V peak, 3.16 V RMS corresponds to full scale on display. Outputs are short circuit proof to ground and output current are in excess of 10 mA

Analogue to Digital Converter :
Converter type :   16 bits linear
Sampling rate :   64 kHz, 15.625 µsec

Filters and Networks :
Anti-aliasing filter : 10-pole Chebychev low-pass filters
Frequency range : DC to 27.6 kHz
Passband ripple : < 0.1 dB
Stopband attenuation : > 75 dB above 1.3 × cut-off frequency
Phase matching : < 0.1 ° for 10 Hz - 5 kHz., <1.0 ° for 0.1 Hz - 10 kHz

Digital filters : 6-pole llR filters for 1/1- and 1/3-octave bands. The 1/3-octave centre frequencies are set with the factor 10^n/3
Frequency range : 0.125 Hz to 16 kHz for 1/1-octave bands or 0.1 Hz to 20 kHz for 1/3-octave bands
Filter response : The 1/1 and 1/3-octave filters meet the requirements from IEC 61260 class 1
Weighting networks : The true A and Lin-networks fulfill the requirements to BS EN 60651 Type 0 for precision sound level meters
Lin network : 25 Hz to 16 kHz, - 0.3 dB and 17.8 Hz to 22.3 kHz, - 3.0 dB
Calculated networks : A, B, C and Lin-networks as well as up to 4 user defined networks may be calculated as a sum of the frequency band within the set frequency limitations.

Level Detector :
Detector Type : Digital true RMS
Resolution : 0.1 dB in accordance with BS EN 60651 and BS EN 60804 Type 0
Linearity Range : 75 dB, BS EN 60804 type 0
Pulse range : 78 dB, BS EN 60804 type 0
Accuracy : 20 Hz to 12.5 kHz
• +5 dB above to 60 dB below FS : < 0.2 dB
• 60 dB to 70 dB below FS : < 0.4 dB
• 70 dB to 80 dB below FS : < 1.0 dB
Time constants : Selectable in a binary sequence from 1/16 s to 8 s. plus Impulse.
• The 1/8 s (Fast), the 1 s (Slow) and the Impulse are in accordance with BS EN 60651 Type 1
Integration period : 4 ms to 100 hours with 1 ms resolution.
Crest factor capability : 10 dB crest factor margin at FS increasing to 90 dB at 80 dB below FS

Display :
Display type : 10.4” bright, back-lit, TFT, VGA colour LCD screen.
Picture resolution : 640 (horizontal) × 480 (vertical) pixels - VGA standard
Display formats : one or two windows, with or without added information. Each window may individually present data from selectable channel and selectable parameter(s), as a numeric table, as a level vs. frequency graph, or as a level vs. time graph.
Displayed range : selectable to 20 : 40 : or 80 dB
Graphical resolution : 0.1 dB to 0.8 dB depending on selected format
Numerical resolution : 0.1 dB
Numerical range : -99.9 dB to +199.9 dB

Measurement Storage :
Internal storage : up 32.000 full frequency single channel spectra.
• Actual usable number will vary, based on used channels, used registers, used parameters and used frequency range.
Floppy-disk : 1.44 Mbyte 3-1/2” floppy-drive DOS compatible format gives approximately 250 single mode measurements
• or 100 multi-spectrum measurements each having 1000 periods.
Hard-disk : Minimum 2.1 Gbyte hard disk MS-DOS compatible format gives approx. 262,500 single mode measurements
• or 105,000 multi-spectra measurements each having 1000 periods.

Digital Interfaces :
Control : Almost any setting or any data readout may be done using the digital interfaces
IEEE-488 :Meets the IEEE Standard 488-1978.
RS-232C : Meets the RS-232C Standard for normal serial interfaces with handshakes.
Printer : Graphic screen-dumps or numeric tables may be printed out using the Centronics parallel interface.

Signal Generator :
Output : BNC connector
Output impedance : <10 ohm, ±10 mA
Signal types : Random or Pseudo-Random noise.
Spectra : White, Pink, 1/1-octave or 1/3-octave noise.
Repetition rate : approx. 28 minutes corresponding to 0.00006 Hz spectral line separation
Filters : the 1/1- and 1/3-octave filters meets the requirements from IEC 61260 class 1
Output level : selectable in 1 dB steps in the range 0 to 60 dB relative to 1 Vrms

General :
Power requirements : 30 W : 11-15 VDC.
Dimensions : 34 × 21 × 35 cm (W×H×D) without battery case
Weight : 9.7 kg without battery (12.3 kg with Battery Case type 330A)

Overall Performance :
The overall performance of the Nor-840 with a suitable microphone and preamplifier, such as the Norsonic 1220 and 1201, corresponds to the Sound Meter Level Standards BS EN 60651 Type 1, BS EN 60804 Type 1
The filter characteristics are designed after the most stringent criteria of the Filter Standard IEC 61260 class 1 for analogue and digital filters as well as the ANSI S 1.11 - 1986 Type 1D. The filter also meets the older IEC 225 Filter Standard.