Introduction:
NA70 is a multichannel noise measurement and analytical instrument discretionarily combining noise and vibration measurement。It can achieve the real-time measurement of noise and acceleration and other physical quantities..High-speed computing by PC, high-capacity storage capacity, analyse and calculate the time domain and frequency domain of the collected signal.It has much advantages such as multiusage,high precision,etc. Can be widely used in environmental noise measurement, ambient vibration measurement, the spectrum analysis of 1 / 1, 1 / 3 noise source, real-time FFT analysis, architectural acoustic measurement.
NA70Multichannel noise / vibration analyzer is composed of computer, package, high speed A / D board, measuring amplification board, charge amplification board, accelerometers, preamplifier, measuring microphone
Technical Parameters:
1、 Noise measurement channels
（1）Measurement microphone: Φ12.7mm polarization condenser microphone, sensitivity: about 30mV/Pa
（2）Frequency range: 20Hz-20kHz
（3）Background noise: direct input short circuit, A weighted less than 5μV
（4）Frequency weighting: A, C, Z (linear), can meet the requirement of IEC61672-1: 1
(5) Anti-mixed filter: built-in, cut-off frequency of 40kHz, 2.5kHz, 630Hz, 200Hz, attenuation -48dB/oct
(6) Range: 20dB、40dB、60dB、80dB
(7) AC output: 7V maximum RMS
(8) Range: 25 ~ 140dB with the 30mV/Pa microphone
2、Vibration measurement channels
（1）Sensors: Piezoelectric Accelerometer, Charge Sensitivity: ≈ 10mv / m • s-2
（2）Frequency range: 20Hz-20kHz
（3）Measuring Range: 0.1-5×102m/s2
3、High-speed and high precise A / D board
（1）Sampling Frequency: Up to 200kHz
（2）Sample Level: 16 bit
（3）FIFO: 32k byte
（4）Interface:USB
Main Software:1)FFT analysing and testing
(1) You can set the type and sensitivity of the sensor in the setting window
(2) A / D sampling rate can be randomly set
(3) Can separately adjust measuring range of every channel and maximum frequency of anti-aliasing filter
(4) Can automatically generate longitudinal coordinates according to the type and range of sensor
(5) Can store and print the measuring result
(6) Can display both the FFT analytical result and the time domain waveform
(7) The same software can be used to measure both the noise and the vibration, the user can randomly select testing peak or effective value
2)OCT analysing and testing
(1) Sampling rate: 50kHz / channel
（2）Dynamic range: 80dB
（3）Center frequency：20Hz,25Hz,31.5Hz,40Hz,50Hz,63Hz, 80Hz,100Hz,125Hz,160Hz,200Hz,250Hz,315Hz,
400Hz,500Hz,630Hz,800Hz,1000Hz,1250Hz1600Hz,20000Hz,2500Hz,3150Hz,4000Hz,5000Hz,6300Hz,8000Hz,10kHz、12.5kHz、16kHz
（4）Parallel 1/3OCT analysis
(5) Can store and print the measuring result
3) Architectural acoustics measurement
According to the GBJ75-84”The Construction Noise Regulation”, it can measure laboratory measurement of airborne sound insulation of building components, measure on-the-spot airborne sound insulation between the two rooms inside the buildings, measure on-the-spot airborne sound insulation of the outer wall and the outer wall components,measure airborne sound insulation of impact sound of floors and measure on-the-spot airborne sound insulation of impact sound of floors,etc.It can automatically transform sound insulation result to evaluation quantity of single-valued according to the GBJ121-88”The Evaluation Criteria of Construction Noise ”,and can do reverberation time measurement according to the GBJ76-84”The Reverberation Time Measurement Regulation of Living Room”.
4) Sound absorption coefficient measurement
(1)It can do the laboratory measurement of sound absorption coefficient according to the GBJ47-83” The Sound absorption coefficient measurement Regulation of Reverberation Room”
(2) It can do the reverberation time measurement according to the GBJ76-84” The Reverberation Time Measurement Regulation of Living Room”
(3)You can select the repetitive measuring time from 1 to 18 times when measure the reverberation time. Measuring with 1 / 3 octave,center frequency are 50Hz、63Hz、80Hz、100Hz、125Hz、160Hz、200Hz、250Hz、315Hz、400Hz、500Hz、630Hz、800Hz、1000Hz、1250Hz、1600Hz、2000Hz、2500Hz、3150Hz、4000Hz、5000Hz、6300Hz、8000Hz、10000Hz.
4) Measuring lower limit frequency can be randomly selected by user among 50Hz, 63Hz, 80Hz, 100Hz
5) The maximum frequency can be randomly selected by user among 5000Hz,6300Hz,8000Hz,10000Hz
6)It can automatically print the measuring report according to the request of GBJ47-83” The Sound absorption coefficient measurement Regulation of Reverberation Room”
7) Measurement range of reverberation time is from 0.2s to 10s
8) Can simultaneously calculate T60，T50，T40，T30，T25，The user can define slope of decay curve to calculate the T60
9) All measurement results can combine with EXCEL, WORD and other software
10)Can display,store and print the time-domain waveform
11) Can display,store and print the various time-changing graphics as frequency component changes
12) Can display,store and print the frequency characteristic graphics of reverberation time
