Soft dB I-Track User Manual

Soft dB Inc.
1040,
Quebec (Quebec) Canada G1S 3G3
Toll
E-mail: [e-mail]

I-Track

Real-Time Sound Mapping System &
Automatic Sound Power Measurement

User guide – V4.02

Belvedere Avenue, Suite 215

free: 1-866-686-0993 (USA and Canada)

Contents

1 Introduction ............................................................................................................................. 1

2 Components ............................................................................................................................ 1

3 Warranty .................................................................................................................................. 2

4 Quick Start ............................................................................................................................... 3

4.1 Sound Mapping Measurement ............................................................................................................... 3

5 Main Interface ........................................................................................................................ 10

5.1 Menu Bar ....................................................................................................................................................... 10

5.2 Map Scale ...................................................................................................................................................... 11

5.3 Map Tools ...................................................................................................................................................... 11

5.4 Spectrum ....................................................................................................................................................... 11

5.5 Number of Points ....................................................................................................................................... 11

5.6 Measure Indicators .................................................................................................................................... 11

5.6.1 Input Ranges ................................................................................................................................. 11

5.6.2 Signal Buffer .................................................................................................................................. 11

5.7 Measure Controls ....................................................................................................................................... 12

5.8 Comments .................................................................................................................................................... 12

5.9 File Controls ................................................................................................................................................. 12

6 Configuration Setup .............................................................................................................. 13

6.1 Measure Setup (next) vs File Setup (current) ................................................................................... 13

6.2 Setup Interface ............................................................................................................................................ 13

6.2.1 Info .................................................................................................................................................... 13

6.2.2 Input ................................................................................................................................................. 14

6.2.3 Output ............................................................................................................................................. 18

6.2.4 Advanced ....................................................................................................................................... 19

6.2.5 Display ............................................................................................................................................. 22

6.2.6 Configuration File ....................................................................................................................... 23

6.3 Record Setup................................................................................................................................................ 23

i

Conductor

Alto 6i

1 Introduction

Congratulation on your purchase of the I-Track Sound Mapping System.

I-Track is a powerful tool for easy and accurate sound intensity cartography. It combines machine
vision with high performance DSP acquisition to produce sound intensity maps. The result is a low
cost, accurate, easy to use tool appropriate for both field and laboratory measurements. Sound
Intensity maps are the ultimate noise source analysis tool.

2 Components

I-Track system with

rugged laptop with embedded DSP

I-Track system with

External USB DSP analyzer

(Probe and camera not shown)

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3 Warranty

SOFT DB INC. warrants this instrument to be free of defects in parts and workmanship for one year
from date of shipment (a six-month limited warranty applies on sensors and cables). Should it be
necessary to return the instrument for service during or beyond the warranty period, please
contact us at [phone] for authorization or visit our website at
Contact for more information). A return authorization (RMA) must be issued before any product is
returned to Soft dB. The sender is responsible for shipping charges, freight, insurance and proper
packaging to prevent damage in transit. This warranty does not apply to defects caused by the user
such as misuse, improper wiring, operation outside of specification, improper maintenance or
repair, or unauthorized modifications. Soft dB specifically disclaims any implied warranties or
merchantability or fitness for a specific purpose and will not be liable for any direct, indirect,
incidental or consequential damages. Soft dB’s total liability is limited to repair or replacement of
the product. The warranty set forth is inclusive and no other warranty, whether written or oral, is
expressed or implied.

www.softdb.com (Click on

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4 Quick Start

4.1 Sound Mapping Measurement

Step 1 Launch Software

Start the I-Track SMP software:

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Step 2 Take Background Picture

Before performing a sound mapping measurement, a background picture must be taken. In order
to do this, plug the digital camera on a USB port and click the “New Measure” button on the
software interface or on the intensity probe:

This will launch the background picture interface:

This interface allows adjusting the camera parameters, such as focus, luminosity and contrast. It
also allows checking for appropriate probe detection: place the probe with the visual tracking
device in the field of view of the camera and a green polygon should be drawn on the detected
probe. When satisfied with the image, click OK to accept and return to the main interface.

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Step 3 Run a Measurement

When returned form the background picture interface to the main interface, the recently acquired
background image should be displayed in the map indicator. Click the “Run” button on the
interface or press the equivalent button on the intensity probe to run the measurement.

When the measurement starts, scan the virtual measurement plane. The sound map will be painted
in real-time. When the probe displays red buttons, it means that the camera doesn’t detect the
probe, when it displays green buttons; it means that the probe is detected and that points are
acquired.

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Step 4 Stop the Measurement

When the measurement is done, click the “Stop” button on the software interface or press the
corresponding button on the probe:

If the “AutoSave” mode is enabled, the measurement is automatically saved in the record directory
when the user stops the measurement:

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Step 5 Post-processing

When the measurement is recorded, the map computation process is launched. This computation
process performs advanced operations on the acquired data to display a highly accurate result.
These advanced functions require working on the whole dataset and therefore cannot be
performed during the acquisition process.

At any time the user can cancel this process to perform another measurement right away.

At the end of this computing process, the resulting map and spectrum are displayed:

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You can select the displayed band by clicking on the corresponding band on the spectrum.

Step 6 Exporting Data

The exported data consists of map images (.png) and spectrum data (Excel compatible .txt file). A
simple image export can be performed by sending the current map to the clipboard and pasting it
in the target document.

Image sent to clipboard

To export the current dataset, select “Export Current” in the “File” menu. This function will export
all the maps as *.png files and the data in an Excel compatible .txt file.

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5 Main Interface

Menu Bar

Map Scale

Map Tools

Spectrum

5.1 Menu Bar

The Menu bar allows access to different functions, interfaces and tools.

Nb Points
Meas Indic.

Meas Ctrls

Comments

File Ctrls

• File;

• Open;

• Save;

• Save as;

• Export current;

• Export multiple;

• Quit.

• Setup;

• File setup (current);

• Measure Setup (next);

• Tools

• Field Check;

• Field Indicators;

• Playback;

• Power-process;

• 3D view.

• Help

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• About;

• Shortcuts;

• User Guide.

• New Measure.

5.2 Map Scale

This area displays the color scale of the sound map and also displays the title of the dataset
displayed in the map, such as global sound intensity or 1 kHz Sound Pressure.

5.3 Map Tools

• Display setup: Access to the current display setup.

• Zoom map: Allows zooming the map.

• Copy map to clipboard: Copies the map image to the clipboard to paste in a target

document.

• Draw Map Boundaries: Allows the user to draw a contour on the map. This contour defines

the boundaries for power computation and average sound intensity and sound pressure.

5.4 Spectrum

This indicator displays the spatially averaged spectrum of the map.

5.5 Number of Points

This indicator displays the number of data points in the map.

5.6 Measure Indicators

5.6.1 Input Ranges

The two top horizontal slides display the microphones A and B input ranges respectively. The fill
scales represent the current and maximum reached value. When input saturation occurs, the slide
becomes yellow and the maximum value becomes red.

5.6.2 Signal Buffer

The bottom horizontal slide displays the input buffer. This buffer ensures a real-time processing of
the time signal and ensures that every sample is processed. If the computer on which the software
is executing is not powerful enough to perform the process or that another task is

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5.7 Measure Controls

These controls are used to control the measurement. These controls can be accessed either form
the remote control probe or directly on the software interface.

• Run / Pause: Starts, pauses and resumes a measurement;

• Stop / Save: Stops and saves a measurement;

• New Measure: Launches the background picture interface.

5.8 Comments

These text controls allows the user to add comments to a measurement.

• Measure Comment (Next): This comment will be applied to the next measurement when it

starts.

• File Comment (Current): This comment is the comment of the currently loaded data

whether from a recently performed measurement or from a loaded measurement file.

5.9 File Controls

The path indicator displays the currently loaded measurement file and the Next and Previous
buttons are used to navigate to the next and previous files of the current directory.

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6 Configuration Setup

The configuration setup is an aggregate of different information which relates to a measurement
such as:

• File information;

• Software version;

• Start time-stamp;

• Comment;

• Etc.

• Input setup;

• Microphone calibration;

• Phase mismatch compensation;

• Microphone spacer;

• Etc.

• Etc.

This information is recorded with the measurement file, dictates how the data is interpreted and
provides useful information to the user when post-processing the files.

6.1 Measure Setup (next) vs File Setup (current)

The I-Track software is used for both the acquisition and the post-processing of sound maps.
Therefore, separate configuration setups are used, the first applies to the next measurement and
the other applies to the current data, either a loaded file or a recently performed measurement.

The Measure Setup (next) allows defining parameters that will be used for the upcoming
measurements, such as the microphone calibration to use for the next measurement whereas the
File Setup (current) incudes parameters that were used for the measurement of a particular file or
recently performed measurement.

6.2 Setup Interface

The Setup Interface allows the user to define or view the parameters included in the configuration
setup. This interface is accessible in the “Setup” menu. Select “Measure Setup” to modify the next
measurement configuration or “File Setup” to modify the current file configuration.

6.2.1 Info

This Interface shows information on the measurement such as the hardware used to perform the
measurement, the measurement date and time, user comment, etc.

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6.2.2 Input

This interface shows the inputs configuration. This is where the user can perform microphone
calibration.

Microphone A

Microphone B

Phase

PI Residual

Microphone Spacer

Sensor Info

The sensor info contains information such as manufacturer, model and serial number of
microphones in use. It also allows defining the input channel, the range and the sensitivity of each
microphone.

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Amplitude Calibration

The amplitude calibration interface allows calibrating the sensitivity of each microphone using a
single-tone calibrator.

To perform a calibration:

1) Place the calibrator on the selected microphone and turn the signal ON;

2) Set the appropriate frequency and amplitude of the calibration signal on the interface;

3) Enter the calibrator info (optional);

4) Click the “Start Calibration” button to launch the calibration process.

It is strongly recommended to perform a calibration of each microphone before each
measurement.

Phase Compensation

The phase compensation allows compensating for phase mismatch of a microphone set to
increase the dynamic capability of the intensity probe. This phase compensation calibration tool is
intended to work with the GRAS 51AB Residual PI Calibrator connected to the Alto or Conductor
output, but could also be used with another residual PI calibration device.

To perform a calibration:

1) Connect the PI residual calibrator to output 1 of the Conductor or Alto;

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2) Insert both microphones in the calibration chamber;

3) Enter the calibrator info (optional);

4) Click the “Start Calibration” button to launch the calibration process.

It is recommended to perform a phase mismatch compensation calibration before each
measurement campaign.

Some PI Residual calibrators require a certain time to equilibrate the pressure in the calibration
chamber after the insertion of the microphones.

PI Residual and Dynamic Capability

The Pressure-Residual Intensity (PI Residual) of the instrument (IEC 1043:1993) is used to define the
dynamic capability of the instrument (ISO 9614-1, 2 and 3). This PI Residual measurement tool is
intended to work with the GRAS 51AB Residual PI Calibrator connected to the Alto or Conductor
output, but could also be used with another residual PI calibration device.

To perform a PI Residual measurement:

1) Connect the PI residual calibrator to output 1 of the Conductor or Alto;

2) Insert both microphones in the calibration chamber;

3) Enter the calibrator info (optional);

4) Click the “Start Measure” button to launch the measure process.

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It is strongly recommended to perform an amplitude calibration and a phase mismatch
compensation calibration prior to the measurement of the PI residual. Enabling phase mismatch
compensation increases the PI residual and the dynamic capability of the instrument.

Some PI Residual calibrators require a certain time to equilibrate the pressure in the calibration
chamber after the insertion of the microphones.

Microphone Spacer

The microphone separation is an important parameter in the sound intensity evaluation from the
pressure gradient. In order to provide precision measurement of sound intensity, the microphone
separation distance must be carefully selected in function of frequency range.

The input configuration allows defining the selected microphone spacer. It also provides a
reminder tool to select the appropriate spacer. If a single spacer doesn’t provide a bandwidth
which is large enough to appropriately evaluate the sound intensity over the whole frequency
range, the measurement must be repeated using different spacers and combined afterwards.

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Recommended frequency range for most common microphone spacers (mm)

6.2.3 Output

This interface shows the output configuration. The outputs of the Conductor or the Alto can be
used to generate different signals during the measurement. Two outputs can be used and several
signal types can be combined.

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6.2.4 Advanced

The advanced parameters can be adjusted in this interface.

Delta t

The Delta t value sets the time interval between each acquired point. Therefore, the time signal
equivalent for this measurement point will be averaged over this time interval. As an example, a
0,125 s time interval means that 8 points per seconds will be acquired and each of them will
integrate the time signal on a 1/8 s duration.

When FFT is selected, an overlap of 66.6% is applied as a result of the Hanning windowing.
Therefore, a time interval of 0,125 s means that 24 points per second will be acquired and each of
them will integrate the time signal on a 1/8 s duration. Each point averaging period will overlap the
previous and next averaging period by 33.3%.

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Temperature, Pressure and Humidity

The temperature, pressure and humidity parameters allow the user to define the atmospheric
conditions prevailing during the measurement. The software will compensate the intensity results
to provide standardised results at 20°C, 101.325kPa and 50% Humidity (ISO 5011).

Grid Precision

The grid precision defines de precision of the computing grid. Typically, the grid precision must be
about 1/100 the source size to provide a good precision over computation speed ratio. As an
example, when measuring a laundry machine, measuring about 1 m wide, a 1 cm grid precision
would be appropriate, when measuring a mining truck measuring about 8 m long, a grid precision
of about 5 to 10 cm would be sufficient.

Max Distance and Max Angle

The maximum distance and maximum angle refer to the measurement plane definition. The result
of a sound mapping measurement is a cloud of points in space. These points are roughly
distributed on a virtual measurement plane. The I-Track software will automatically compute the
optimal plane position which minimises the distance of each measurement point to the
measurement plane. Points that are located too fare from the measurement plane and that are not
perpendicular to the measurement plane will be rejected. These maximum distances and angle are
defined by the Max Distance and Max Angle parameters.

Pattern Size and Microphone Offset

The pattern size and microphone offset refer to the dimension of the probe and the visual tracking
device. These dimensions are used by the software to provide accurate positioning of the probe in
space.

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Microphone Offset

Pattern Size

Maximum Time and Maximum Speed

The maximum time and speed refer to the tracking parameters. The maximum time specifies the
maximum elapsed time between two acquired positions to validate the path between these two
positions. Typically, 1 s maximum elapsed time is appropriate.

The maximum speed specifies the maximum speed for a segment path to be valid. A maximum
scanning speed of 0.5 m/s is required by ISO 9614-2.

Averaging Distance and Maximum Interpolation Distance

The averaging distance sets the averaging radius for Gaussian averaging of the sound map. Set to
zero to disable averaging. The maximum interpolation distance defines the maximum distance
between two measurement points to interpolate data between these points.

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6.2.5 Display

The display interface allows setting several display parameters.

These parameters are:

• Spectrum: 1/1 Octave, 1/3 Octave or FFT;

• Weight: A, C or Z (no weight);

• Bandwidth: Low and high frequency range to consider. The global level is computed on this

frequency range;

• Displayed Value:

• Pressure, Intensity or PI index;

• Global level or single frequency;

• Color Scale:

• Manual Range: the user sets the maximum and minimum values of the color range;

• All Data: the maximum and minimum values in the map are used to define the

maximum and minimum values of the color range;

• 10, 5 and 3 dB MS: Sets the color range to the most significant dB of the map. As an

example, if the maximum value of the map is 93.8 dB and the 5 dB (MS) setting is
selected, the color scale will range from 88.8 to 93.8 dB.

• Display Sign: Allows the user to select the displayed intensity sign :

• Positive Only;

• Negative Only;

• Both Signs (Absolute).

• Transparency: Sets the transparency of the sound map over the background image;

• View Grid: Displays the computing grid on the map;

• View Points: Displays the measurement points on the map;

• View Tracks: Displays the scanning tracks on the map;

• View Triangles: Displays the triangular interpolation structure on the map.

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Grid Points

Tracks Triangles

6.2.6 Configuration File

The configuration file allows saving all the settings in a single file to be recalled later or to transfer
settings from an I-Track system to another.

6.3 Record Setup

The Record Setup allows defining the record directory and the file prefix to use when auto-saving.

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