ONO SOKKI - DS-0223 Real-time Octave Analysis Software

1/1.1/3 Real-time Octave Analysis Software DS-0223

Real-time 1/1, 1/3 Octave Analysis Software
DS-0223

	To DS-2000 Multi-Channel Data Station
	To CF-3600 Portable FFT Analyzer
	Basic Terms for FFT Analysis

Example of noise measurement of arterial highway Blue: Equivalent Continuous Sound Pressure Level (Leq) Green: Single-shot Sound Exposure Level (Lae)	This software can perform 1/1 or 1/3 real-time octave band analysis from 2 to 32 channels at the frequency range of 0.5 to 20kHz. DS-0223V is available for 2-ch, DS-0223W is for 4 to 8-ch, and DS-0223X is for 10 to 32-ch. Sound filter conforms to IEC, JIS and ANSI. By setting the measurement time, Equivalent Continuous Sound Pressure Level and Single-shot Sound Exposure Level can be calculated simultaneously. Also, it can be recorded level fluctuation of each band (time-series) at maximum 2,000 points. Using those data, Percentile Sound Pressure Level for each band can be calculated. Operating system is Windows2000 / XP / VISTA. Based on this software, the function can be expanded with optional software DS-0224, 1/6, 1/12, 1/24 real-time octave analysis and DS-0243, rotation-tracking analysis by real-time octave band. Equivalent Continuous Sound Pressure Level: An average value which is obtained by dividing t-hour (s) of total level by t. Single-shot Sound Exposure Level: A value as converted t-hour (s) of level to one-minute of level.


<What is Real-time octave analysis> When noise control countermeasure is taken, frequency analysis is required. Octave analysis has been used as one of the way for noise analysis. Octave represents the ratio of frequency is 1 to 2, that means 2 times of frequency. Feeling of human hearing has characteristics in equal ratio which respects to the frequency. In view of this feature, octave-band series is standardized based on the frequency at 1kHz. The sound pressure of each band is obtained through the standardized band-pass filter. The octave-band based on the frequency at 1kHz is called 1/1 octave-band, and then further division to three of 1/1 octave-band is called 1/3 octave-band.


Data example
Example of sound level trend (time history level) of excavator Red：All pass (total level) Blue：2kHz Green：4kHz Yellow：8kHz
Example of level trend by 3D mapping display
Example of Percentile Sound Pressure Level at arterial highway (L_x) Display for L₅ to L₉₅, L_max, L_min, L_avg of each 1/3 octave-band with 2D graph ※Percentile Sound Pressure Level: It indicates the percentage of level in t-time. L₅₀ is called central value, which is the middle value counted from maximum level.

Specifications

（１）Input section

Number of channels	32 channels at maximum (simultaneous processing)
Input impedance	1MΩ / approx. 120pF
Input voltage range	Applied every 10dB, in 6 steps
Input connector	BNC voltage input, Applicable to CCLD 2mA, 4mA
Frequency weighting	A, B, C, FLAT (conforming to IEC 651 Type 0), analog filter
Sensitivity setting	Settable for each channel （calibration function)

（２）Filter and detection section

Calculation method	All digital calculation method （Digital filter and Digital RMS)
A/D conversion	24bit, 64kHz sampling
Dynamic range	85dB or more
Filter type	6th Butterworth
Conforming standards （Filter)	JIS C 1514-2002 Class 1 IEC 61260 Ed.1.0 (1995) Class 1 ANSI S1.11-2004 Class 1
Frequency range	0.5Hz to 20kHz (1/3 OCT) 1.0Hz to 16kHz (1/1 OCT)
Time constant	10ms, 35ms, FAST (125ms), 630ms, SLOW (1s), 8s, IMPULSE

（３）Measurement section

Measurable physical characteristics of sound	Sound pressure level for each band Sound pressure level of band composition （OVERALL) Sound pressure level of FLAT (ALLPASS)
Basic measurement	INST (Instantaneous value), MAX (Maximum value for each second) MAX.H （Band maximum value within the measurement time for power operation data) MIN.H （Band minimum value within the measurement time for power operation data) P AVG (Average value of instantaneous values within the measurement time for power operation data, which is equivalent to the equivalent sound level) P SUM (Value obtained by converting the sum of instantaneous values within the specified measurement time for power operation data into the average power level for each second. Equivalent to the single-shot sound exposure level.)
Second processing	L_x (L₁, L₅, L₁₀, L₅₀, L₉₀, L₉₅, L₉₉) Differential function（Difference of dB value, difference of antilog value (background noise correction) Level trend function（Plotting the graph showing level changing in arbitrary band, second processing after memorized）

（4）Display section

Display format

Bar graph display (Allband+Allpass+Overall）
Monitor display （Time trend monitor display）
List display （Allband+Allpass+Overall）
Level trend display （from continuous recording band data）
3D/2D level trend display (color)

（5）Memory section

Memory capacity	2000 blocks/ch, Continuous recording of INST data (level trend function)
Recording interval	1ms to 10s (valiable)
Number of saving data	Up to 500 data items can be saved
Address for storing data	Can be stored to arbitrary folder with arbitrary file name.

（６）Data input/output function

Analysis condition file	Open/save of arbitrary measurement condition file
Print function of data	Print function by installing of printer driver
Copy function of data	Pasting data on clipboard at text or bitmap format

Applications for real-time octave analysis

Applications
	Analysis for noise characteristic in automobile cabin Analysis for sound pressure characteristic of acoustic product Testing for noise from compressor Testing for noise from exterior unit for air conditioner Analysis for low-frequency sound Measurement for environmental noise and vibration Measurement for traffic noise Measurement for vibration of handheld tool

Revised: 2009/01/30