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Contents
1 Introduction ............................................................................................................................. 1
2 Hardware Description ............................................................................................................. 1
2.1 Computer Requirements ........................................................................................................................... 1
2.2 Mezzo Precision Microphone Specifications ...................................................................................... 1
2.3 Accessories ..................................................................................................................................................... 2
3 Mezzo Noise Analyzer Measurement Module ....................................................................... 3
3.1 Ribbon Pane ................................................................................................................................................... 4
3.1.1 File Menu .......................................................................................................................................... 4
3.1.2 Display Menu .................................................................................................................................. 5
3.1.3 Setup Menu ..................................................................................................................................... 6
Input Setup ........................................................................................................................................7
Microphone Calibration Interface ....................................................................................................................... 8
Data Setup .........................................................................................................................................9
Record Setup .................................................................................................................................. 10
3.2 Control Pane ................................................................................................................................................ 11
3.3 Display Pane ................................................................................................................................................. 12
3.3.1 Time Bar .......................................................................................................................................... 12
3.3.2 Data Display .................................................................................................................................. 12
Time History Graph....................................................................................................................... 13
Spectrum Graph ............................................................................................................................ 14
Table Display .................................................................................................................................. 16
Event Viewer Interface ................................................................................................................. 17
1
1 Introduction
Congratulations on your purchase of the Mezzo Precision Microphone. This instrument provides an
innovative and cost effective solution for professional grade acoustical measurement. More than
just a DAQ, the DSP embedded in each Mezzo Precision Microphone ensures real-time signal
processing. Moreover, the Mezzo uses a proprietary driver ensuring signal integrity.
Designed to be used with a tablet PC or any other Windows based PC, the Mezzo Precision
Microphone takes profit of the versatility and flexibility provided by computers. This approach also
allows offering the Mezzo Precision Microphone along with a measurement module from the
Mezzo Software Suite at a very competitive price. Used along with the Mezzo Noise Analyzer
measurement module, the Mezzo Precision Microphone complies with IEC 61672 (2013) Class 1
standard.
The Mezzo Precision Microphone is compatible with the following modules of the Mezzo Software
Suite:
• Noise Analyzer: SLM, RTA, FFT & advanced post analysis.
• Noise Monitor: SLM, RTA, FFT & advanced monitoring functionalities.
• Building Acoustics: room noise, reverberation time, airborne sound insulation, impact
sound level & more.
• Waveform Recorder: signal recording & advanced post-processing tools.
The current user’s manual describes the Mezzo Precision Microphone hardware and its use through
the Mezzo Noise Analyzer module.
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2 Hardware Description
The full measurement system mainly consists of a host computer that is connected to the Mezzo
Precision Microphone through USB cable. The computer is the responsibility of the owner since
Soft dB does not sell it. Section 2.1 describes the requirements that should give guidelines in its
selection.
2.1 Computer Requirements
Computer Requirements
Item Minimum Requirements
Operating System Windows XP SP3, Vista, 7, 8 or 10
CPU Dual-Core at1.2 GHz
1
Memory 2 GB RAM
Hard drive 300 MB free hard disk space
Port USB 2.0
Display resolution 800 x 600
2.2 Mezzo Precision Microphone Specifications
Mezzo Precision Microphone Specifications
Item Specifications
Microphone
BSWA MPA221 (Class 1)
2
or BSWA MPA225 (Class 2)
3
Connector SMB
Peak Maximum Level
4
Low Range: 112 dB
pk
High Range: 126 dB
pk
Noise Level
5
Low Range: 22 dBA, 20 dBC, 25 dBZ
High Range: 32 dBA, 30 dBC, 35 dBZ
Under-Range Limit Level
6
Low Range: 32 dBA, 30 dBC, 35 dBZ
High Range: 39 dBA, 37 dBC, 42 dBZ
Input Range
Low Range: 0.42 V
pk
High Range: 2.1 V
pk
Maximum Sampling Rate 48 kHz
Signal Conditioning IEPE
Communication USB 2.0 (Mini B connector)
Dimensions 230 x 32 x 23 mm
Power Supply USB Powered (Max 0.35W)
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If using the 1/24 octave spectrum, the CPU requirement is Dual-Core at 2.4 GHz.
2
½” MP201 Mic with MA221 Preamp – 50 mV/Pa, IEC 61672 (2002) Class 1, SMB Connector.
3
½” MP215 Mic with MA221 Preamp – 40 mV/Pa, IEC 61672 (2002) Class 2, SMB Connector.
4,5,6
Evaluated according to IEC 61672 (2013) Class 1, using 50m V/Pa sensitivity.
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2.3 Accessories
Included Accessories
Component Description
Mezzo Unit
The Mezzo Precision Microphone without the actual microphone.
Dimension (with microphone): 228x31x22mm (9x1.22x0.86”)
ICP Microphone
BSWA MPA221: ½” MP201 Mic with MA221 Preamp – 50 mV/Pa, IEC 61672 (2002) Class 1
or
BSWA MPA225: ½” MP215 Mic with MA221 Preamp – 40 mV/Pa, IEC 61672 (2002) Class 2
USB Cable 1 m USB 2.0 cable with Mini B connector
Windscreen 50 mm diameter windscreen
Case Plastic transport case Dimension: 268x240x57mm (10.5x9.5x2.25”)
Optional Accessories
Component Description
Extension Adapter Plugs a wire into the Mezzo unit in order to deport the microphone. Coming soon…
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3 Mezzo Noise Analyzer Measurement Module
The Mezzo Noise Analyzer measurement module is part of the Mezzo Software Suite and is
included with the Mezzo Precision Microphone. It offers a professional sound level meter with a
real-time spectrum analyzer and advanced post analysis functionalities.
Main interface of the Noise Analyzer Module
General Module Specifications
Parameter Value
Available Data
Time weighting: Slow, Fast or Impulse.
Frequency weighting: A, C and Z.
Global levels, octave spectrum (1/1, 1/3, 1/24) and FFT spectrum.
Live data: SPL, Peak, live Leq.
Periodic Average and Overall Average data: SPL Stats (Lmin, Lmax and selected LN%), Peak max, Leq.
Taktmax.
Bandwidth
1/1 octave: 16 Hz to 16 kHz
1/3 octave: 12.5 Hz to 20 kHz
1/24 octave: 11.4 Hz to 22.1 kHz
FFT: 0 to 22 kHz
Audio Events Periodically and on trigger. Wave or MP3 format.
Data save
Levels data and audio events are added to the measurement file as they become available during the
measurement.
Three save modes are available:
• Single Period: Save the overall average data at the end of the measurement. It is simple and
creates small files but it does not allow any post analysis (post periods and masks).
Ribbon
Pane
Display
Pane
Control Pane
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• Multiple Periods: saves the raw periodic average data at each period end. The time resolution
in post analysis directly depends of the selected Average Duration and it produces files with
reasonable sizes.
• Instant Data: saves the raw instant data (live) at the instant rate. It allows the best time
resolution in post analysis but the files are heavier.
Display
All measured data (both live and overall) can be displayed during the acquisition.
In post analysis, the available data depends on the record mode.
The main panel is scalable (smaller is 660 x 430 pixel)
Post Analysis
Available on files that used the Multiple Periods or Instant Data as record mode.
Evaluation of the average level on post intervals from the raw data (either instant data or periodic
average).
The bounds of the post intervals can be set manually or automatically.
Masks can also be applied to filter unwanted events.
Possibility to use several scenarios of different intervals and masks.
Miscellaneous
Export the overall data to Excel.
Automatically reconnect and restart a measurement if an error occurs.
3.1 Ribbon Pane
3.1.1 File Menu
File Menu
File Menu
Icon Description
The Open button prompts the user to open data files (.mspa).
Several files can be loaded all at
once given that they are part of the same measurement.
These two buttons open the previous/next data file in the Record Directory.
This button exports the loaded data into a tab delimited file (.txt). The Export interface sets the
data to be exported. The exported file can be easily opened with any spreadsheet application such
as Microsoft Excel.
This button prompts the user to select several files to be exported in a batch process. The same
Export interface al
so sets the data to be exported according to the setup of the first selected file.
Each source file is exported into its own export file.
This button opens the File Info interface (figure below).
It contains the information on the measurement over several tabs:
• General information (including Comment)
• Input setup
• Data setup
• Audio setup
• Record Setup
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They are all indicators except for the comment, which can be modified either while measuring or
once the measurement is completed.
In the bottom left of the panel, the record rate and the remaining record duration are estimated.
File Info Interface
3.1.2 Display Menu
Display Menu
Display Menu
Icon Description
The Live mode displays the current level during the measurement (Live SPL, Leq or Peak).
The Overall mode displays the overall level (SPL Max, Min and LN%, Leq or Peak Max).
While acquiring the display can be toggled between Live and Overall mode.
Only Overall is available when displaying data from a previous measurement.
Toggles between the SPL, Peak, Leq or Taktmax data.
If the Data Setup is set to FFT, only the Leq button is available.
Toggles between the SPL Max, Min or Stat data. These controls are only available when
displaying the SPL data type in Average mode (periodic or overall).
While measuring :
Post Analysis :
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Sets the statistic to be displayed when the Overall SPL Stats data are selected.
Selects the applied frequency weighting: A, C or Z (no weighting). The A-
weighting is the
most common. The three wei
ghtings are evaluated in parallel in the time domain except
for the spectrums, for which the dBA and dBC are obtained by applying the frequency
weighting on dBZ spectrum.
Sets the frequency of the selected spectrum (octave or FFT) to be display in the time
history graph. For an octave spectrum, the left/right arrows can be used to shift to the next
band.
3.1.3 Setup Menu
Setup Menu
Setup Menu
Icon Description
The Input button calls the Input Setup interface.
It mainly sets the sensitivity and range of the sensor.
The Data button calls the Data Setup interface.
It mainly sets the data to be evaluated and recorded.
The Audio button calls the Audio Setup interface.
It mainly sets when to record audio events.
The Record button calls the Record Setup interface.
It mainly sets the record destination and the file management.
The Import Setup button prompts the user to load a measurement setup from a file. The source file
can be previously exported configuration (.cfg) or measurement file (.mspa).
The Export Setup button prompts the user to save the current measurement setup into a file (.cfg).
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Input Setup
Input Setup interface
The left part of the Input Setup interface is related to the Mezzo Analyzer (without the sensor) and
the right part is related to the microphone.
Input Setup Interface – Mezzo Analyzer Parameters
Control / Indicator Description
Model of the detected hardware.
Serial Number of the detected hardware.
Selects the input channel to be measured if several channels are available on
the detected hardware. The Mezzo Precision Microphone is single channel.
Selects the Low or High input range be used during the measurement.
The indicators show the
amplitude range of operation. Those values change
according to the sensitivity and the selected gain.
Input Setup interface – Microphone
Control / Indicator Description
The Manufacturer, Model and Serial Number of the microphone
Sets the Sensitivity of the microphone.
To set the sensitivity, a level calibration is usually done using the Microphone
Calibration interface. It can also
be set by manually overwriting the Sensitivity
field.
Loads the microphone information from the Mezzo memory (factory defined)
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Microphone Calibration Interface
The microphone can be calibrated using the Microphone Calibration interface and a sound
pressure calibrator.
Microphone Calibration interface
1) Adjust the Calibrator Level and Calibrator Frequency according the sound calibrator used.
Most calibrators generate 94 dB at 1 kHz.
2) Install the sound calibrator on the microphone and start the calibration signal.
3) Press Run to start the calibration measurement.
4) Wait a few seconds until the measured level stabilizes. 10 seconds should be enough.
5) Press Stop. The sensitivity is updated according to the calibration measurement.
6) If the new Sensitivity value is acceptable, press OK
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Data Setup
Data Setup interface
The Data Setup varies slightly according to the Record Mode used in the Record Setup.
Data Setup interface
Control / Indicator Description
The Duration field indicates the period duration.
The Align button allows aligning the
periods with the clock. If set to False, the periods
will be aligned with the starting time.
In Instant Data record mode, the Instant Rate directly impacts the file size of the
measurement. Otherwise, it only set the reading rate of the SPL values
used to
evaluate the average data.
The minimum and default value of 50 ms is appropriate to measure Fast (and Slow)
SPL in respect of the CEI 61672 requirements. However,
a higher instant rate can be
useful when the host PC is struggling to run the software in real-time.
Selects the SPL time weighting that will be use during the measurement.
The check boxes let the user selects that data to be evaluated, displayable and
recorded. Some data have a check without the box to show that the it cannot be
disabled.
The FFT spectrum bandwidth is user defined: 20k, 10k, 5k, 3.33k, 2k or 1kHz.
It corresponds to the frequency resolution: 20, 10, 5, 3.33, 2, and 1Hz.
Average Data Setup
Single Period
or Mutltiple Periods)
Instant Data Setup
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Record Setup
Record Setup interface
Record Setup interface
Control or Indicator Description
Selects the save mode:
• Single Period: only saves the measurement overall average at the end
of the measurement
• Multiple Periods:
saves several average periods (Average Duration) as
each period ends.
• Instant Data: saves the instant data at each sample time (Instant Rate).
Select the directory where are the measurements are saved.
The default directory is User Documents\Mezzo\SPA.
This list-box allows selecting the file name format. Choices are:
• YYYYMMDD_hhmmss
• MMDD_hhmmss
• DD_hhmmss
This list-
box allows selecting the automatic file increment behavior. Choices are:
• On Start Only (no periodic file increment)
• Every Hour
• Every Day
• Every Week
No matter how the File Increment is set, a file reaching the size of 1 gigabytes
(1 GB) will also be incremented.
Afterwards, several files of the same
measurement can be opened all at once.
This list-box allows selecting the automatic stop mode. Choices are:
• User Stop (no automatic stop)
• Duration (stops after a specified duration)
• Stop time (stops at a specific moment)
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3.2 Control Pane
Control Pane
It should be noticed that most of the controls and indicators found in the Control Pane are
duplicated on the Mezzo Presicion Microphone. Therefore, the Status, Sat, Run/Pause, Stop/Save
and Fn (when applicable) have the save functionalities on the probe and in the software.
Controls & Indicators
Control / Indicator Description
The duration of the measurement in format HH:MM:SS.
The Run/Pause button starts or pauses the measurement.
The pause is only
available when the Save Mode is set in Single Period.
The Stop button stops the measurement.
The Comment button directly accesses the comment for viewing or editing.
The comment is also available in the General tab of the File Info (File Info)
The Status color indicates what is the acquisition state:
• Grey: acquisition off
• Yellow: acquisition paused
• Green: acquisition running
The Sat color indicates if an
overload occurred since the beginning of the
measurement:
• Grey: no overload detected
• Red: overload detected
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3.3 Display Pane
Display Pane
3.3.1 Time Bar
Time Bar
Control / Indicator Description
This time
slider gives time information about the measurement and the display
data.
•
The leftmost and rightmost values: measurement start and stop time
respectively.
•
The grey cursors that enclose the blue span: the time span on the Time
History graph.
• The yellow cur
sor: the time cursor on the Time History graph and the time
used to display a value on the Spectrum graph or Stats Table.
The cursor can be moved directly from the slider control.
The magnifier buttons zoom in and out the span of the Time History.
The arrow buttons shift left or right the span of the Time History.
This control displays the current value of the time cursor on the slider (also the
cursor on the Time History graph). The exact time value should be set here.
3.3.2 Data Display
The Data Display area can displayed either a time history graph, a spectrum graph (1/3 octave or
FFT) and a table (SPL statistics or weather).
Time
Bar
Data
Display
Display
Menu
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Time History Graph
Time History Graph
The Time History displays the selected data selected in the Display Menu. The time span of the
graph is set from the Time Bar.
Time History Graph
Control / Indicator Description
This legend gives the main information on the data being displayed:
• The display type.
• The period (instant or average).
• The time span of the data.
• The data name and the value of the cursor on the graph.
The arrow buttons shift left or right the cursor on the graph.
If the OL indicator is red, it indicates that an overload occurred. During
measurement, the overload stays red as soon as an overload is detected u
ntil a new
average period starts. In post-
process, the overload is red if an overload occurred
during the displayed average data.
If the UR indicator is blue, it indicates that an under range occurred. During
measurement, the under range stays blue only wh
ile the under range is detected.
In post-
process, the under range is blue if an under range occurred during the
displayed average data.
This event graph shows when events occurred. The cursor and time span match
those on the main graph below. The audio records appear as blue lines.
In post process, clicking on an event opens the Event Viewer interface.
This button opens the Y Axis Format interface from which the vertical scale of the
graph can be modified. The Minimum and Maximum fields can be set
manually or
automatically using the Auto-Scale Now button.
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Spectrum Graph
Octave Graph display (1/3 octave)
FFT Graph display
The spectrum graph displays the data selected in the Display Menu. The time of the data can be set
by moving the yellow cursor in the Time Bar.
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Spectrum Graph
Control / Indicator Description
This legend gives the main information on the data being displayed:
• The display type.
• The period (instant or average)).
• The time span of the data.
• The data name and the value of the cursor on the graph.
The arrow buttons shift left or right the cursor on the spectrum and global graphs.
If the OL indicator is red, it indicates that an overload occurred. During
measurement, the overload stays red as soon as an overload is detect
ed until a new
average period starts. In post-
process, the overload is red if an overload occurred
during the displayed average data.
If the UR indicator is blue, it indicates that an under range occurred. During
measurement, the under range stays blue onl
y while the under range is detected.
In post-
process, the under range is blue if an under range occurred during the
displayed average data.
This small graph displays the global level of the requested data in the three
frequency weightings (A, C and Z).
This event graph shows when events occurred.
The Level span matches the one on the main graph beside.
This button opens the Y Axis Format interface from which the vertical scale of the
graph can be modified. The Minimum and Maximum fields can be set
manually or
automatically using the Auto-Scale Now button.
This button opens the X Axis Format interface from which the horizontal scale of
the graph can be modified. The Minimum and Maximum fields can be set manually
or automatically using the Auto-Scale Now button.
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Table Display
Table display – SPL Statistics
The Table display is usually used to display the SPL.
Table Graph
Control / Indicator Description
This legend gives the main information on the data being displayed:
• The display type.
• The period (average period or overall)
• The time span of the data.
• The data name
If the OL indicator is red, it indicates that an overload occurred. During
measurement, the overload stays red as soon as an overload is detected until a new
average period starts. In post-
process, the overload is red if an overload occurred
during the displayed average data.
If the UR indicator is blue, it indicates that an under range occurred. During
measurement, the under range stays blue only while the under range
is detected.
In post-
process, the under range is blue if an under range occurred during the
displayed average data.
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Event Viewer Interface
Event Viewer Interface
The Event Viewer allows listening to recorded events. To launch the Event viewer interface, click on
the event history on top of the time history graph to view the selected event. The Event Viewer
interface also allows to view the event type (trigger vs periodic), as well as its start and end time.
Also, the button can be used to export the audio event into standard files.
