SCS 8400 series: Advanced andMultiplatforms Software Packages for

Acoustic Power Determination accordingto Internationl Standards

Application Note

The SCS 8400 series software calculate SoundPower level according to all relevant standards ISOand EU by taking measurements from a wide rangeof hardware and software platforms manufacturedfrom major trade-mark on the market. Some peculiarand rather unique features are:

the Wizards to guide step by step the user thorugh all pro-cedures up to the final results, the menu driven characteristics without many windows toopen and close, the Windows Explorer database navigator, the MS-Office Access standard database, the support of Wireless Lan for data transmissionear driver Lp measurement

WizardBy using wizards the user isguided through all steps.

Standard selection to selectthe standard to be applied.

Hardware selection:Select the hardware availa-ble. If you select the2000/14/CE directive only,than any supported SLM/RTAw/out MUX10A hardware canbe used. WIthin 01dB pro-ducts range is not evennecessary to chose the hard-ware since all of them areautomatically supported asthe interface is directly to the01dB dBTrig software.

Frequency range: some frequency band can beexcluded from data acquisition and Sound Power cal-culation.

Measurement surface typecan be selected and the posi-tion of the machine inside themeasurement surface.Measurement surface coordi-nates (X,Y,Z can be insertedand the software will calculateautomatically the measure-ment surface area S. Than, ithas to be select the numberof microphones (measure-ment points).

Sound field selection if themeasurement zone is in afree field or not. In a free fieldis not necessary to calculatethe K2 factor (environmentalfactor). The K2 table can bedefined manually or can becalculated using reverbera-tion time data (MESA DSPlusfeature).

Time history (raw signal) canbe saved for further proces-sing as wav files or other for-mat supported. "Total measu-rement time…" is the maxi-

mum measure time forevery channel. Machine property. Theuser can define the valuesof each property (machinename, type, engine type,…). The LWA limit value willbe used to validate or not each LWA measurements.

After completion of the "new file wizard" there will betwo new window in the main window : "General infor-mation" window realted to file properties, and"Microphones" where it's possible to configure everymicrophone. To change the position of one micropho-ne jsut have to right click on the microphone numberand move the mouse pointer to new position, thanchange its status (Green = enabled, Red = disabled,Yellow = enabled only for operator ear noise measu-rement)

CalibrationInside SCS 8400 SoundPower Software it's possibleto perform a "Standard cali-bration" or an "Automaticcalibration". Depending from the hard-ware selected theaspect/features of the calibration window will vary.To run the Standard calibration a calibrator is fitted oneach microphone in turn and correction factors can“Accepted” to store the new correction factor or“Cancel” to abort the procedure.In Automatic calibration the software sense all availa-ble channels to detect where the calibrator is actual-ly fitted and switched “On”, and than it calculatesautomatically the new correction factor.

"Discrete tone search" measurement (ISO 7779)To run the discrete tone search procedure it is neces-sary to have build a new data file (or open an existingone) and the selected ISO reference must be ISO7779 or "engineering test mode". It is recommendedto conduct the following listening tests in addition tothe measurement procedure.1. Conduct a general listening test without any comparison tothe reference tones. If the equipment under test sounds tonal,the measurement procedure should be performed for anysuch tones and those identified as prominent according to thecriteria "Prominent discrete tones".2. Perform the measurement procedure on all tones thatappear to be prominent in the narrow-band analysis. For anytones exceeding the tone-to-noise criteria ("Prominent discre-te tones"), play a sine-wave (having the same frequency asthe tone in question) over a headset or loudspeaker and com-pare it to the sound from the product, noting whether or not atone at the sine-wave frequency is audible in the productsound emission.In case where there is a doubtas to whether audible tonesare present or not, other,more objective, evidenceshould be sought (such a nar-row-band analysis of the

Noise and VibrationMeasurement and Analysis Systems Consult and Services for EnvironmentConsult and Services for IndustryWEB & Information technologies

G.Amadasi

DIRECT SUPPORTOF ALL 01dB APPLICA-TION SOFTWARES AND

HARDWARE PLATFORMS

Solo: single chan-nel Sound LevelMeter and RealTime Analyzer

Symphonie:dual-channelsPC based SoundLevel Meter andReal TimeAnalyzer

Harmonie-01dB:quad-channelsPC based SoundLevel Meter andReal TimeAnalyzer

Orchestra: multi-channels (4-200)PC based multi-purpose RealTime Analyzer

OPTIONAL SUPPORTOF OTHER HARDWAREPLATFORMS FROM PRI-MARY TRADE-MARKS

Major Trade-marks supported:Rion NL& SA series (w/out Multiplexer)B&K 2250-2260 (w/out Multiplexer)Norsonic SA 118 and 121National Instruments: Sound andVibration products as PCI card, PXIframe, CRio series

DIRECT SUPPORTOF SCS-MESAPLATFORMS

MESA DSPlus:12 channels SoundLevel Meter and RealTime Analyzer

MESA MUX 10A:10 channels Multiplexerwith Instrumented Inputsand ICP support

MESA S4 Plus:4 channels - 24 bits - PCcard Instrumented Inputsand ICP support

Standards supported:ISO 3741, 2, 3, 4, 5, 6, 7 - ISO 6393, 4, 5, 6 - ISO 11094 - ISO 7779 - EU 2000/14/CE

noise). In this case to be sure ifone or more discrete tones arepresent or not it is necessary torun the "Discrete tone search"procedure. A specific wizardhas been prepared and oncethe hardware is ready the inco-ming signal is displayed on thescreen.

"Auto range" button perform anautorange for all the configu-red channels and than recor-ding can be started. A progressbar will show on the screen the recording status.

When the recording is com-pleted a page appears onthe screen with stored data.On each data recording anFFT can be applied byselecting the correspondingrow and FFT lines resolu-tion. A new row with FFTdata result will become availa-ble and displayed.

Autospectrum (FFTresult) of the selectedrecord appears on thescreen; cursors positioncan be set and thanapply "Search tone"option.

Cursors position can be setusing mouse left and right but-tons, by press and drag opera-tion. Once the cursor range isdefined than it can be pressed"Calculate".

The program perform the following calculation :F0 : Central frequency of the tone (between F1 and F2)F1 : Left cursor positionF2 : Right cursor positionDeltaF : Frequency range from cursor F1 to cursor F2Lt : Sound pressure level (dB) of the discrete toneF1c : Left cursor that define the critical bandwidth areaF2c : Right cursor that define the critical bandwidth areaDeltaFc : Size of the critical bandwidthLn : Sound pressure level (dB) of the masking noise, exclusive

of the tone, contained within the critical band (F1c-F2-c) centered at the frequency of the tone (F0)

Lt-Ln : Tone-to-noise ratio (dB)

The level Lt is taken as the sound pressure levelcontained in the narrow band that just delineates thetone. The Lt value is determined by bracketing thedata points that define the tone with the analyzer'sband cursors, and then computing the power in thisband. If the width of the frequency band selected tobracket the tone is greater than 15% of the width ofthe critical band, the measurement should be repeatwith a different resolution bandwidth. If it continues toproduce a signal for witch the bracketed tone's band-width is greater than 15% of the critical bands, thenthe tone is bracketed by a band centered on the fre-

quency of the tone whose width is 15% of the criticalband. When this condition is detected a message boxappear on the screen.

In this example select the"Cancel" button to set thesize of the DeltaF to the15% of the DeltaF critical band. Select the "Cancel"button only if you have already tried to use a greaterFFT resolution but the result are still the same.

Calculation are completed andthe result is show in the"Calculation result" frame.

A discrete tone is identified asprominent if, and only if, thecondition is detected: ( Lt - Ln ) >= 6.0 dB

At any moment during the wizard press the button"Cancel" to abort the "Discretetone search" procedure. Tosave data result select the"Next" button. The wizard iscompleted, data will be storedin the current openSoundPower data file and adata summary will be displayon the screen.

"Reverberation time" measurementThis option is enabled only if selected measurementarea is indoor. Reverberation time measurementprocedure varies depending ofthe hardware selected, somedevices wil directly measure theRT, alternatively the softwarecan record the audio signal andperform directly the calculation;a new window appear on thescreen.

Option "Use two channels" is available (depending ofthe hardware) for reverberation measurement usingtwo channels at the same time. Option "Noise gene-rator" is also available in case of some 01dB devicesand Mesa DSPlus.

Once the measurement recording has been comple-ted, data are automatically stored into the currentopen data file and a windowappear on the screen (reverbe-ration time edit window) sho-wing a decay curve for each fre-quency band. Using the option"Lock cursors" all set of RTvalue will be calculated accor-ding to the cursor positions onany of them.

Sound Power measurementwindowUpon completion of wizard, cali-bration and RT optional measu-rements, the determination of

Sound Power becomes an easy task with few mouseclicks.

Data acquisitionBy starting data acquisition adynamic window shows thespectra in Real Time of a cer-tain number of channels,depending of the hardwaredevices connected.

Background noise measurentBackground noise measure-ment can be taken at any timeby selecting Data acquisition.

Miscellaneous table allows toidentify each single item under-going the LWA test, connect ameteo data station, associte tothe file other information andnotes.

Results Data Measurements taken and stored into the databasegives the LW result simply by pressing a button, morethan one measurementcan be stored in thesame file. A gray characters set ona measurement columnmeans that data will notbe used in the LW calcu-lation, a red font colorfor a single numbermeans a calculationerror. Data can be viewed astables or graph.

Export menu offer several choicesfor exporting data, current selec-tion, to text file or other format.

Post processingAll dataset might consist of wav files (raw signal), MSAccess files, txt, etc. and any kind of post processingcan actually be applied, like: audio analysis (FFT, 1/noctaves, filtering), measurements statistics, etc.

ReportingThe easiest way for professional reporting it is to useMS Office automation to include data files within anMS Word template or MS Excel table.

SecurityThe access to the program can be restricted to usersand one administrator, the restriction applies mainlyto the internal data base, only the administrator canactually modify acquired or calculated data in the MSAccess environment.Users can perform measure-ment and consult (read only)the internal database.

Application Note

Sedi operative in: EU, USA, ASIASedi principali:

Rappresentante - Sede locale:

www.scs-controlsys.com info@scs-controlsys.com

10051 Avigliana (TO)Via Gandhi, 13Tel.:+39.011.9348705Fax:+39.011.9348703

35011 Campodarsego (PD)Via Antoniana, 278Tel.: +39.049.9200975Fax: +39.049.9201239

SCS 8400 Software series has applications for almost every kind ofmachinery subjected to Noise certification and Sound Power labeling.Some common examples are:ISO 639x for earth moving machines (CNH, Hyunday, Daewoo, JohnDeer, Backhoe Loaders Mini Excavators, Samsung, Fiore, ......); ISO 11094 for gardening machines (Castelgarden, .....)ISO 374x and 7779 for Office machines (Seagate, Panasonic, .....); ISO 374x for Air conditioners (Apen group, Galletti, ....); ISO 374x for Household appliances (Electrolux, Whirlpool, .....).