XL3 Instruction manual
Version: V 1.26.0 Rev. 2024-01-15
Firmware: V 1.26

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Table ofContents
1 Overview / Interfaces
1.1 Interfaces
1.2 Onboarding

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2 Operation
2.1 Operation via the keypad
2.2 Operation via the display
2.2.1 The status bar
2.3 Quick settings
2.4 Data access and remote control via web browser

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3 Commissioning
3.1 Power supply
3.1.1 Li-Ion battery
3.1.2 Operation with mains adapter
3.1.3 Supply via USB cable
3.2 Attach hand strap / Kensington lock3.3 Fold-out stand3.4 Acoustic measurements
3.5 On / Off
3.6 System settings
3.6.1 General
3.6.1.1 Language
3.6.1.2 Time zone
3.6.1.3 Decimal separator
3.6.1.4 Save
3.6.1.5 Color scheme
3.6.1.6 Display timeout
3.6.2 Connections
3.6.3 Installed options
3.6.4 Rechargeable battery
3.6.5 About this device
3.7 Selection of the measurement function

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4 Measurement Functions
4.1 Sound level meter4.1.1 Page selection by means of page key
4.1.2 Page selection via the display
4.1.3 Numerical level display
4.1.4 Level-time history
4.1.5 Spectral display
4.1.5.1 Zoom and scroll of the axes
4.1.6 Settings
4.1.6.1 Report & Logging

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Spectra32

Logging interval

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Audio recording

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Audio format

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Sampling rate

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Memory consumption of WAV files

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Levels to be recorded

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4.1.6.2 Gliding Leq level
4.1.6.3 Level statistics
4.1.6.4 Define K-values
4.1.6.5 Display layout
4.1.7 Carrying out a sound level measurement
4.1.7.1 Test preparations
4.1.7.2 Start measurement
4.1.7.3 Stop measurement
4.2 Reverberation time
4.2.1 Page selection by means of page key
4.2.2 Page selection via the display
4.2.2.1 Spectral display
4.2.2.2 Reverberation time graph4.2.2.3 Reverberation time table
4.2.3 Perform reverberation time measurement
4.2.3.1 Select project folder
4.2.3.2 Configure reverberation time measurement
4.2.3.3 Perform reverberation time measurement

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Single measurement

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Measurement series

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4.2.3.4 Measurement file
4.3 Sound insulation
4.3.1 Measurement sequence & page selection

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5 Data transfer
5.1 MTP (Media Transfer Protocol) over USB-C
5.2 Remote access via XL3 website
5.3 SFTP access

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6 How to connect a router or gateway
7 Remote control via web server
7.1 Activate the web server
7.2 Response of the device in the internal network
7.3 Addressing the device from an external network
7.4 Access to NTi Connect service
7.4.1 XL3 web server
7.4.2 Remote control via the web user interface
7.4.3 Fair Use Principle for NTi Connect
7.4.3.1 Free Data Volume
7.4.3.2 Throttling upon Exceeding
7.4.3.3 Effects of Throttling
7.4.3.4 Recommended Option

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7.4.3.5 File Push Service
7.4.3.6 Reserved Rights

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8 Options and accessories
8.1 Weather station
8.2 GPS Mouse

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9 Calibration
9.1 Calibration of the measuring device
9.2 Microphone sensitivity calibration
9.3 Environmental conditions
9.4 Ambient noise
9.5 Calibration screen
9.5.1 Calibration menu with ASD measuring microphone connected
9.5.2 Calibration menu without sensor connected
9.6 Custom calibration
9.6.1 Customer calibration - Manual sensitivity adjustment
9.7 Free-field correction
9.7.1 Application example
9.8 Class 1 sound calibrator
9.8.1 Technical details
9.8.1.1 Calibration details
9.8.2 Accessories
9.8.2.1 Complainant key

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10 Technical data XL3
11 Technical data measurement microphones
11.1 Calibrateable measuring microphones
11.2 Non-calibratable measuring microphones

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12 Technical data microphone preamplifier
12.1 Free-field correction
12.1.1 Application example
12.2 Diffuse field correction
12.2.1 M4261 1/4" microphone
12.2.2 M2340 1/2" microphone
12.3 Windscreen corrections
12.3.1 Windscreen 50 mm correction (1/2")
12.3.2 Windscreen 90 mm (1/2")
12.4 Correction weather protection WP30-90/-150
12.4.1 Horizontal sound incidence (ambient noise)
12.4.2 Vertical sound incidence (e.g aircraft noise)
12.5 Frequency weighting filter

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13 Safety instructions5

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1 Overview / Interfaces

1 Overview / Interfaces
Thank you for purchasing the XL3 Acoustic Analyzer. The XL3 is a very powerful class 1 acoustics analyzer with network access. It bases on the latest developments of processors, converters and display technologies ensuring easy and comfortable operation of the system.
The broad set of functionality is optimized for the following applications:Sound level measurements & unattended noise monitoring:
Environmental noise analysis;
Workplace noise measurements;
Car and traffic noise.
Room & Building acoustics:
Reverberation time;
Airborne noise isolation;
Structure-borne noise isolation;
Facade isolation.

1.1 Interfaces
These here are the interfaces and controls of the XL3.

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1 Overview / Interfaces
Balanced XLR microphone or audio input. The XLR input has an automatic sensor
detection ASD, i.e. as soon as an NTi Audio microphone is connected, the XL3 automatically switches on the 48 V Phantom power and reads the calibration data of themeasurement microphone.
Programmable digital input/output interface for controlling external devices (e.gweather station) or detecting external input signals (e.g. via the complainant key,etc.).
Connection for the supplied XL3 power supply. For specifications, see chapter
Power supply.
Indicates the battery charge status by means of an LED:
No charger / power supply unit is connected;
The charger is connected and the battery is fully charged;
The power supply unit supplies the device with power and charges the battery;(flashing) power supply not sufficient.
USB-C socket for connecting external devices such as 600 000 535 USB-C to LAN
Adapter, as well as for charging the device.
Device for attaching the wrist strap and mounting an anti-theft device (Kensington
Lock).

Internal voice microphone for recording comments.

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1 Overview / Interfaces
Micro SD-card for saving measurement results, or display graphics, WAV files.
USB-A socket for connection of external devices.
Keypad for operating the XL3.
High-resolution,color touchscreen for the device control and for displaying measurement results, etc.
Headphone output to listen to the input signal.

¼" thread for mechanical mounting of the XL3 (e.g. on a photo-tripod).
Replaceable Li-Ion battery.
Fold-out stand for convenient operation on a table.
Built-in speaker to listen to the input signal or recorded comments. The internal
speaker is automatically disabled when headphones are connected.

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1 Overview / Interfaces

The nameplate can be found underneath the battery and contains all information
about the hardware version, serial number and device configuration.
This push-button contact is used to reboot the device from the inserted SD-card.
Do NOT press this button unless instructed by the NTi Audio support.

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1 Overview / Interfaces
The built-in light sensor will allow the XL3 to automatically adjust the brightness ofthe display and LEDs to the ambient conditions if desired (planned).
(dark) no network connection;(yellow) Network detected, but no connection established yet;(white) Connection to the internet established;(blue) connected to connect.nti-audio.com.
This LED indicates, whether the instrument is in TA-mode (Type Approval):
Whenever this LED is lit, only the certified modules of the sound level meter are active, i.e. the measurement results can be used in court.

1.2 Onboarding
The XL3 will automatically guide you through the onboarding procedure:a. When you switch the instrument ON the for the first time;b. After a factory reset (switch the XL3 OFF, then press+

simultaneously).

Step 1This is the welcome screen of the onboarding procedure – please wait.

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1 Overview / Interfaces
Step 2
Tap on the corresponding dropdown menu toselect the preferred
Language (e.g. Deutsch / English / Français/ ...)
Time Zone (UTC = Coordinated Universal
Time)
Decimal Separator ("." or ",").
You may also edit any of these settings at a later time (see General).

Tap on "NEXT" to proceed.

Step 3
Select the preferred Wi-Fi network from the listand enter the applicable password.
Tap on "Advanced" if you want to add a networkthat is actually not shown in the list, or to delete all
passwords that have been saved so far on the
XL3.

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1 Overview / Interfaces
Alternatively, you may also connect the XL3 to a
wired LAN network by plugging an Ethernet cablevia adapter to the USB-C connector.

Tap on "<" to return to the previous step or on"NEXT" to proceed.

Step 4
Optionally enter a password and an individual
Device Name for your XL3.
The web server functionality
becomes available only when you
enter a password (see Data transfer).

Tap on "<" to return to the previous step or on"NEXT" to proceed.

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1 Overview / Interfaces
Step 5The onboarding procedure is now finished.

Tap on "<" to return to the previous step or on"START" to proceed to the Sound Level Meter
mode.

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2 Operation

2 Operation
The XL3 offers the latest technologies with a large color touchscreen and an additional keypad
for safe and intuitive operation. In addition, you can also control the entire XL3 remotely via a
web browser.

2.1 Operation via the keypadWith the keypad you control the basic functions of the instrument, such as starting or stopping ameasurement, switching between different displays or pages, or moving the cursor within achart view (e.g sound level spectrum).

Keypad of the XL3

The device keys
Switches between the result views. Press and hold the button to lock the touchscreen.

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2 Operation
Press the On/Off key for approx. 2 seconds to switch ON the XL3.
During operation, press the On/Off key briefly to switch the display ON or OFF(but not the meter).
When the display is switched OFF, the key shows the state of the instrument:
Pulsing slowly – XL3 is ON;
Flashing – Measurement is running;
Panic blinking – User interaction required.
To switch OFF or to restart the XL3, press the On/Off key for approx. 3 seconds.
Moves the cursor horizontally (left / right) within a chart view (e.g spectral display).

The ESC key terminates any selection and closes the open window. The cursor
returns to the main menu.
By pressing the OK button you confirm the current cursor selection, as for
instance the measurement function or the parameters.
Starts a measurement.
Stops the current measurement.

2.2 Operation via the display
You can operate the XL3 easily and silently via the touchscreen. In addition to simple inputs,
the touchscreen also supports swipe gestures to change the displayed page.
A long press on the

key locks (or unlocks) the touchscreen to prevent accidental oper-

ation.
The display of the XL3 is divided into the following function segments:

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2 Operation
The status bar displays general information such as the time of day, network
status, microphone connection and battery
status. Swipe down to expand this area.
Tap on the Main Menu to select therequired measurement function (available
measurement functions depend on the
installed options).
Display area of the measurement results.
The preferred display can be selected byswiping left/right on the touchscreen, or via
the
key.

Current status (e.g. "READY","LOGGING" or "PAUSE"), together withelapsed time of the ongoing measurement.

2.2.1 The status bar

Always shows the current time of the device on the left. The time is automatically synchronizedwith the internet via the NTP protocol when there is a network connection.
The microphone symbol indicates that an ASD-compatible NTi Audio microphone is connected, and the calibration data has been read.
Valid Wi-Fi connection; the number of segments represents the signal
strength.
Network connection created via 600 000 535 USB-C to LAN Adapter.
The File Push service is active and the XL3 is uploading the files from its
internal memory to the cloud drive.
The XL3 has pushed (i.e uploaded) all the files from its internal memory
to the cloud drive.
An error has occurred during the uploading process, or the service isincorrectly configured; check the log file for more information.

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2 Operation
Icon

Animation

Meaning

StaticCurrent charge status of the Li-Ion
battery (100% = full); an animatedicon indicates that the battery is charging.

StaticStandard discharge

StaticLow battery level

Blinking

Critical battery level

Slow charge levelanimation (every 1s)

Slow charge (Could happen if useda 5V USB connection)

Fast charge levelanimation (every 0.5s)

Fast charge (With a USB-PD charger or through the DC jack)Slow charge levelanimation (every 1s)

Connected to power supply but
unable to charge

Blinking

Temperature error while charging ordischarging

StaticBattery error (e.g battery has been
removed during operation)

StaticNo battery detected

Blinking

Critical error

Static(red) WARNING – Battery failure!
Observe the error message (seechapter Commissioning) or contact
the NTi Audio support.

A Weather station is connected to the XL3.
The connection to the weather station has been interrupted.
A GPS Mouse is connected and working.
The signal is too weak to get the GPS location.

2.3 Quick settings
Swipe down across the display to get access to the quick settings.

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2 Operation
Record screenshot – tap this icon to recorda PNG picture of the current screen; alternatively, you may also press the two arrow
keys+
simultaneously. The
recorded picture will be saved on the SDcard.
System settings
Calibration screen
Connections
Rechargeable battery
Display brightness – move the slide controller to the left (darker) or right (brighter)to adjust the brightness of the LCD.

2.4 Data access and remote control via web browser
For detailed instructions on how to set up and use the web browser for data access, pleaserefer to chapter Data transfer.

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3 Commissioning

3 Commissioning
3.1 Power supply
You can power the XL3 in several ways:
Replaceable, rechargeable Li-Ion battery (supplied with the XL3);
Mains voltage adapter (supplied with the instrument);
USB-C cable.
The battery is approximately half charged when delivered and should be fully
charged before using the XL3 for the first time.
3.1.1 Li-Ion battery
The protected and certified Lithium-Ion battery must only be used in the XL3. No other use ispermitted. To insert the battery into the instrument, insert it into the battery compartment withthe plastic tab first and let it snap into place.
In order to minimize the battery charging time it is recommended to leave the
XL3 switched OFF during charging.
Safety information when handling the Li-Ion battery pack:
In order to avoid electrostatic discharges, switch OFF the XL3 before
removing the battery pack;
Never short-circuit the contacts of the battery;
The permissible operating temperature of the battery is between 0 to +45°C (+32 to +113 °F);
Never heat the battery above +60 °C;
Do not solder on the battery;
The battery must not be opened;
The battery must not be operated with reversed polarity;
Dispose of the used battery properly according to the instructions in thismanual.
3.1.2 Operation with mains adapter
The supplied power supply is able to completely power the XL3 in all functions. In this configuration, you may leave the battery in the instrument. The power manager of the XL3 prevents from overcharging the battery. When switched off, the charging time for full charge isapp. 3 hours. It prolongs when the XL3 is in use during charging.

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3 Commissioning
Switched power supply with 9 VDC / 2 A with international adapters for EU, UK,
US, AU.
CAUTION: Non-original mains voltage adapters may affect the measurement
results. Damages caused by the use of a non-original power supply is excluded
from warranty.
External DC power supply
Voltage: 5.8 – 17.0 VDCPower: minimum 6 W
Connection: 2.1 x 5.5 x 9.5 mm
Polarity: Positive pole on inner contact
3.1.3 Supply via USB cable
Fundamentally, a USB connection supplies sufficient power to operate the XL3. Should the battery charged in parallel during operation, it is recommend to use an USB-C connection with 3 A
rating, allowing to fully charge the battery in less than 3 hours. When using a USB-C 1.5 A
rated supply, the charging time is extended to about 6 hours, while with a USB-2 connection
with a rated power of 500 mA, the battery is only charged slowly when the device is turned off –no charging is possible during operation of the instrument in this configuration.

3.2 Attach hand strap / Kensington lockA hand strap is included to secure it during work. This puts the XL3 firmly in your hand.
Pull the thin cord of the hand strap throughthe opening;
Slip the end of the thin string over the loop;
Tighten the hand strap.

3.3 Fold-out standThe practical device stand is located on the back of the XL3. Unfold the wire stand to place themeter in a convenient reading position on a table.

3.4 Acoustic measurements
For acoustic measurements, connect an NTi Audio measuring microphone to the XLR input
in Overview / Interfaces. The microphone is connected directly with the XLR consocket
nector, or via an XLR ASD cable to the XL3.

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3.5 On / Off
Press thekey for approx. 2 seconds to switch on the device; after start-up, the XL3 isready for operation. Pressing the On/Off key again briefly during operation switches the display
ON or OFF, respectively. To switch OFF the XL3, you must press and hold the On/Off key for
approx. 3 seconds.

3.6 System settings
You can open the system settings in two ways:
a. Swipe the touchscreen from top to bottom...
b. Or tap the menu icon in the upper left corner...

... and then select the settings icon.

This opens the System Settings, which includes
all global settings such as storage method, network connections, color scheme, language, time,
options and device-specific information. Tap on
the respective menu item to open the corresponding setting.

3.6.1 General
3.6.1.1 Language
Select your preferred language in this sub menu. The language setting changes all menus (ifavailable – otherwise English appears).
3.6.1.2 Time zone
The date and time of the XL3 are synchronized – as soon as available – with the internet time
via the NTP protocol. Therefore, there is no possibility to change the date or time manually.
However, you can select the time zone (e.g. Europe/Berlin) so that the device time matches
your local time.
3.6.1.3 Decimal separator
For numerical display and storage, make the selection between "." (period) or "," (comma).

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3 Commissioning
3.6.1.4 Save
After completing a measurement, you can save the obtained results in three different ways on
the XL3.
manually

Here, the user is responsible for saving the recorded measurement results. As soon as the measurement has been finished, the Save Result
dialog will open. Therein, you may edit the Folder, Name andComment. After that, tap on CANCEL to abandon or on OK to save areport.
Manual saving is useful, for example, if you are performing trial measurements and do not always want to save all the results.
Measured values that are not saved yet, are retained evenwhen the XL3 is switched OFF. You can still save them bytapping on

promptautomatic

In this mode, after the measurement is finished, the Save Result dialog
appears with the Folder (save location) and the file Name. Before you
confirm with "OK", you can add a note (Comment) or cancel the savingwith CANCEL.
Select this mode if you want to decide situational, whether the measurement results should be saved or if you want to add a comment to yourmeasurement data in each case.
In this mode, the measurement results are written automatically – i.e.
without user interaction – to the SD-card in the predefined project
Folder. The file Name has the format yyyy-mm-dd_SLM_nnn, where
nnn is a sequential number that increases automatically with each subsequent save operation.
Select this mode if you want to be sure that all measurement data arealways stored.

3.6.1.5 Color scheme
Select the color scheme that suits you:
1. "dark" – white font on dark gray background;
2. "blue" – white writing on blue background;
3. "light" – black font on white background.
3.6.1.6 Display timeout
Select the duration after which the display automatically switches OFF when not in use. Six
time-limited increments are available from 5" (five seconds) to 60' (one hour) and "never" (notimeout).
As soon as you touch the switched-off display, it becomes active again.

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3 Commissioning
3.6.2 Connections
You can connect the XL3 to the internet in three ways:
a. Directly via the built-in Wi-Fi transmitter / receiver;b. Via a LAN network using a USB Ethernet adapter or a PC;
c. Via a mobile data connection; for this, the XL3 requires an external gateway connectedto the USB connector and connected using the NDIS protocol.
Regardless of the type of connection, the network LED
status of the connection.

provides information about the(dark) No network connection(yellow) Network detected, but no connection established yet(white) Connection to the internet established(blue) Connected to connect.nti-audio.com

This setup shows the current status of the Wi-Fi
connection and the assigned IP address of thedevice. The IP address is important for the connection with the web server. Under NTi Connect
you may see the URL of the connection server
and the unique connection key of your XL3. This
key and the to be defined password are therequired elements for a connection to the instrument via NTi Connect.
In an internal LAN you may also use theIP address to connect instead.
Shows how much data was usedon the NTi connect server for thecurrent month. The monthly data
rate is limited to 2GB, unless a valid“NTi Connect Open Data 365”
option is installed. See Fair Use
Principle for NTi Connect for further details.

Web ServerLAN

In this menu you can define the password. The web server is automatically enabled when a password is defined – otherwise, it is disabled
As soon as an Ethernet connection has been established via LAN on theUSB port, the network icon in the top line of the display changes toand the IPv4 address is displayed. This address must be known in order
to be able to address the XL3 via the web server.

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3.6.3 Installed options
You can see here a list of all options that are
installed & enabled in this XL3. Active options are
displayed in black font – grayed out options are
not active.
All available options for the XL3 can be installed
on your device via the my.nti-audio.com portal online or through your NTi Audio distributor.

3.6.4 Rechargeable battery
This menu shows you the current battery status and – if connected – the type of the external
power supply (USB or Power Adapter).
In case of a Battery failure, the related error message is shown as well.
3.6.5 About this device
Under this menu item you will find:The serial number of the device;
The selectable device name (factory setting: "My XL3");
The installed firmware version and the indication if this version is up-to-date, or if anewer version is available for download (XL3 must be online).

3.7 Selection of the measurement function
Tap theselection menu at the top left of the display.

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You will then see a list of all available measurement functions. Tap on the desired function sothat it is loaded. Detailed descriptions of therespective measuring functions can be found in
the corresponding chapters.
Measurement functions depend on
the installed options.

For a general functional check and for ensuring best possible measurement
accuracy, we are recommending to check the sound level meter together withthe microphone, using a sound calibrator before executing measurements.
Instructions for this can be found under Calibration.

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4 Measurement Functions

4 Measurement Functions
4.1 Sound level meter
The XL3 together with the measuring microphone forms a precise sound level meter for ambient noise, room & building acoustics, and workplace & industrial noise.
With the M2230 or M2340 measuring microphone and the ASD cable, the XL3 forms a class 1
sound level meter that can be calibrated in accordance with the standards DIN EN 61672-1,
DIN 45657:2005 and DIN EN 61260 (see Options and accessories).
To activate the sound level meter mode, tap the menu icon
tap "Sound Level Meter".

in the upper left corner and then

The XL3 continuously displays the current sound level (i.e. even without a measurement having been started). All averaged levels (e.g. LAeq) refer either to the current measurement
period or – if no measurement is currently running – to the previous measurement period. If
there is no current or previous data, "--.-" appear.
Numerical measured values are updated every 500 ms, regardless of the measurement duration or the selected logging interval. The maximum time span between an averaging and thedisplay is therefore 500 ms. Spectra are updated every 50 ms.
During a sound level measurement with the XL3, all results are available simultaneously, suchas the current sound level, Lmin, Lmax, Leq with the frequency weightings A, C, Z and the timeweightings F and S. The device stores the determined measurement results including all realtime information on the removable SD card. In addition to broadband levels, the XL3 also measures the real-time spectrum in third-octave or octave band resolution according to IEC 61260
Class 1.
For complete documentation of the measured sound levels, you may also record a WAV file inparallel. This helps, for example, to acoustically verify sound events with high level values afterwards, or - if recorded uncompressed - to perform further calculations and analysis.
For live events, the XL3 determines the correction values between the loudest location and themeasurement location, and automatically takes these into account for the level measurement .
By activating the Advanced Noise Measurement option, the following additional functions areavailable in the sound level meter:
Sound exposure level LAE;
Time weighting pulse (I);
Differential level LAIeq – LAeq;
Percentile level Lxy (x = A, C or Z / y = F, S or EQ1"): 0.1 – 99.9%;
Fast data recording in 100 ms intervals for broadband as well as spectral levels;
Audio recording with 24-bit or 32-bit resolution and a sampling frequency of 12, 24, 48 or
96 kHz;27

4 Measurement Functions
Backward delete function (planned);
Pre-trigger (planned).
The sound level measurement function offers a numerical display, a level-time graph and aspectral display, which you can select via the keypad as well as the touchscreen.
4.1.1 Page selection by means of page key

to toggle between the numerical and spectral display. This change
Press the page key
is possible without restriction even during a running measurement.
4.1.2 Page selection via the display
You can also select the desired display with a swiping motion, or by tapping the corresponding
icons.

The Numerical level display shows the selected broadband values. You canchange the font size of the displayed measured values under Display layout to display either one, three or five measured values simultaneously. For each of the displayed measured values you can individually select the frequency and timeweighting, the current live value, maximum, minimum as well as correction values.
The Level-Time graph.
Switches to the spectral display of the measured values and displays the thirdoctave or octave band spectrum with the selected frequency weighting. The frequency scale is selectable. In addition to the spectral values, the A- and Zweighted broadband levels are displayed as a bar graph on the right.
In this menu the sound level meter is configured and the layout of the numerical display can be adjusted. These settings are detailed under Settings.
4.1.3 Numerical level display
This page shows a freely configurable selection of sound levels. You can adjust the page layout
under Display layout.

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4 Measurement Functions
To display or change a specific level, tap on thislevel designation. This opens a menu where you
can select the frequency weighting, the timeweighting and any offset values for this level.
Spectral values as well as percentile values canbe found at More.
If only "--.-" is displayed for a measured value, this is due to the factthat an averaged result is behind it,which is calculated and displayed
only after the START of the measurement.

Under "Limit" you can activate and define a maximum limit ("Red") and an alert limit ("Amber") for
each individual level. As soon as the sound levelexceeds the maximum limit value, the display of themeasured value changes to red. If the sound levelis between the alert limit and the maximum limit,
the display changes to amber (warning). Lower
levels are displayed in normal black. Confirm thelevel input with "OK" on the on-screen keyboard.

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4 Measurement Functions
4.1.4 Level-time history
In level-time history display, two selectable level values are plotted over time, while the measurement
is running. Tap on the red (or blue) curve icon
to open the pop-up panel where you can select thecorresponding levels. If you amend a level during ameasurement, the corresponding curve will re-startat this point.
The level-time graph shows 390 data points,
whereby the Logging interval is defined under Settings.
Tapping on the X-axis scaling toggles
between the full data point view, and twozoom ranges (refer to the table below);
Tap on the Y-axis scaling to adjust its range(zoom) and position (scroll).

Logging Interval
1 sec
100 ms30

History duration
06 min 30 sec
39 secZoom 1
03 min 15 sec
19.5 sec

Zoom 201 min 05 sec
6.5 sec

4 Measurement Functions
4.1.5 Spectral display
In the spectral display up to 2 spectra as well as
the A- and Z-weighted broadband levels are displayed simultaneously.
In the dark area below the spectrum, you canswitch the spectral resolution between 1/3rdOctave and octave resolution on the right and the
cursor mode between Manual and Automatic. In"automatic" mode, the frequency band that has
the highest level is highlighted in orange, while in"manual" mode you can select and highlight a frequency band yourself using theandarrow keys.
If you tap on either of the two level-icons to the leftor
, you will get access to the Frequency
and Time Weighting of the spectral display, as
well as:the Reading of the dashed curve;
the Reading of the bar graph.
4.1.5.1 Zoom and scroll of the axes
By long tapping on the X or Y axis, you canchange the corresponding scale.
For the Y-axis, use the slider on the left to movethe scale up or down, and tap the corresponding
box to select the sensitivity in dB/div. To finish, tap
in the middle of the display next to these fields.
You select the area of the X-axis to be displayedusing the two end points of the slider. To finish, tap
the center of the display again.

The set sensitivities of both axes
have no influence on the measurement or the data recording.

31

4 Measurement Functions
4.1.6 Settings
This page provides access to the following settings:
Selection of sound levels and measurement
parameters to be recorded;
Averaging duration (length of time windows) of the moving Leq levels;the parameters of the percentile statistics;
Input of correction values for offset levelmeasurements;
the layout of the numeric display;(De)activation of measurement series.

4.1.6.1 Report & Logging
At the end of the measurement, the XL3 then automatically generates the measurement reportas a TXT file, if active. In the process, individual sound level measurement values previously
selected by the customer or all sound level measurement values are stored.
Spectraoff
eq
eq, max, min
all

There is no recording of spectral data.
The mean values of the spectrum are recorded.
Average values, minimum and maximum levels are recorded.
The XL3 records all spectra.

Logging intervaloff
1s
100 ms

The selected measurements are saved only when the measurement is finished,i.e. as final results.
The XL3 saves the current measurement data every second.
The XL3 saves the measurement data every 100 ms (i.e. 10 times per second).

Audio recording

off
on

32

The audio recording is switched off.
Parallel to the ongoing sound level measurement, the XL3 records an audio file in
WAV format. This file is available after the end of the measurement for analysis, documentation or further calculations. When audio recording is enabled, the Audioformat and Sampling rate (sampling frequency) parameters can be configured.

4 Measurement Functions
Audio format

The device can record the audio data as uncompressed or compressed WAV files.
Uncompressed (linear PCM), recordings are suitable for making further measurements or calculations later. Be aware that they are occupying a lot of memory.
The compressed ADPCM format, on the other hand, uses only 4-bit per sample, and is therefore very memory efficient. Compressed audio data can be listened to without restriction, e.g.
to identify specific events. However, they are not suitable for downstream calculations.
All WAV files recorded by XL3 can be played back with a common media player.
However, it is important to note that the uncompressed recording formats covera wide dynamic range, and the content on a media player can therefore only bevery quiet / barely audible.
32-bit24-bitcompressed

Uncompressed audio recording is done with a resolution of 32-bit (floating
point), resulting in a dynamic range of 1'528 dB. The maximum level of the
WAV file is fixed to 200 dB.
Uncompressed audio with a resolution of 24-bit, a dynamic range of 144 dB
is available. The maximum level of the WAV file depends on the sensitivityof the microphone and is calculated as: 117.5 dB – 20*log10(mic_sensitivity_in_V/Pa). The maximum level in dB is also encoded in the file name.
This format compresses the audio content with the ADPCM algorithm in 4bit in such a way that the memory consumption is minimized with good audibility. The level of the WAV file is automatically controlled and optimized forgood audibility.

Sampling rate

Audio recording can be done with different sampling frequencies. The higher the sampling frequency, the higher maximum frequencies can be recorded. The highest recordable frequency
corresponds to half of the sampling frequency.
96 kHz48 kHz24 kHz
12 kHzUltrasonic signals up to 48 kHz can be recorded, provided that the cut-off frequency of the measuring microphone supports this.
This sampling rate covers the entire audible audio range up to 24 kHz.
A memory-saving format to record audio signals up to max. 12 kHz.
A memory-saving format to record audio signals up to max. 6 kHz.

Memory consumption of WAV files

The following table shows the memory consumption of all possible combinations.
fs
96 kHz48 kHz24 kHz
12 kHz32-bit31 GB/day – 1.3 GB/h
15 GB/day – 0.64 GB/h
8 GB/day – 0.32 GB/h
4 GB/day – 0.16 GB/h24-bit23 GB/day – 1 GB/h
12 GB/day – 0.5 GB/h
6 GB/day – 0.25 GB/h
3 GB/day – 0.12 GB/hCompressed––
989 MB/day – 41 MB/h
494 MB/day – 21 MB/h33

4 Measurement Functions
Levels to be recorded

Here you can choose between All and Selected. With All, all levels calculated in the soundlevel meter are recorded and are then available for post-processing. In the Selected list you
can enter up to 10 freely selectable levels that will end up in the log file. The level selection is
analog to the level selection in the sound level meter.
4.1.6.2 Gliding Leq level
In addition to the mean value (Leq), which represents the entire measurement period fromSTART to the observation time STOP, there arealso gliding averages Leq_g, which calculate themean value for a defined measurement period up
to the observation time. The XL3 can calculate up
to four averages in parallel.
Example:10:00:00 Start of measurement
10:00: 05 Leq5" = Leq of this 5seconds
10:00:06 Leq5" = Leq of the time
window from 10:00:01 to 10:00:06
10:00:07 Leq5" = Leq of the time
window from 10:00:02 to 10:00:07
Applications:
Measurement of the averaged LAeq over 5 seconds
according to DIN15905;
Measurement of the gliding
LAeq over 60 minutes
according to V-NISSG;

34

4 Measurement Functions
4.1.6.3 Level statistics
The instrument calculates up to 7 different percentile levels for broadband and spectral measurements. These data represent the statisticalsound level distribution, and are typically used forenvironmental noise measurements. Here, forexample, LAFxx% corresponds to a noise levelexceeded during xx% of the measurement period.
The 10 percentile sound levels are flexibly
adjustable from 0.1% to 99.9%.
Specifications:
Broadband and spectral
measurements;
Fast/slow weighted levels
are sampled every 1.3 ms;
Broadband resolution: in 0.1
dB class width;
Octave and 1/3rd Octave
spectral resolution: in 1 dBclass width.

35

4 Measurement Functions
4.1.6.4 Define K-values
At live concerts, you often cannot place the meter
directly at the loudest measurement location(Audience), but must place it at an alternate location (Measurement Position). This leads to differences between the A- and C-weighted levels
measured at the substitute location and those prevailing at the measurement location. You candetermine or correct these differences by a simple
measurement with the XL3.
Procedure:
Temporarily place the instrument at the loudest measurement point, provide a constant sound level (e.g. pinknoise) and perform a measurement with "Audience" –>START;
Then place the instrument at
the replacement measuringlocation and perform a measurement again with "Measurement Position" –>START (while the soundlevel remains constant);
The level differences of the A
level are calculated as k1
value and the difference of
the C level as k2 value.

36

4 Measurement Functions
4.1.6.5 Display layout
Three layout templates are available for thenumeric level display:"Small" displays 5 levels of the same sizenext to each other.
"Medium" displays one level in large font,
and two other levels slightly smaller.
"Large" focuses on a single level that is displayed large.

The selection of displayed levels follows the order of the levels from the"Small" layout. That means, layout"Small" shows all 5 levels, while layout "Medium" shows only the top
three levels of layout "Small". Finally, Layout "Large" shows only the
top level of Layout "Small".
4.1.7 Carrying out a sound level measurement
4.1.7.1 Test preparations
The XL3 reads the electronic data sheet of a connected NTi Audio measuring microphone andautomatically activates the 48 V Phantom power for the measuring microphone.
Connect the measurement microphone to the XLR input;

Switch on the XL3 with the On/Off key;

The 48 V Phantom power display in the upper menu bar changes to ASD
The instrument is now ready for acoustic measurements.

.

Position the measuring instrument at the measurement location, e.g. mounted on a
microphone stand;Select the Sound Level Meter measurement function and press the side key to switch
between the sound level and spectral display;
Select the display of numerical levels select the levels you are interested in;
Define which levels you want to have recorded here: Report & Logging .
The displayed levels behave independently from the recorded levels.

37

4 Measurement Functions

4.1.7.2 Start measurement
A measurement cannot be started, unless a storage device (SD-card or USB
drive) is inserted.

When the XL3 is ready to measure the defined sound levels, press the

button.

The measurement status display switches first to STARTING, then to LOGGING (if logging is switched on, otherwise RUNNING is displayed);
Above the timer, the flashing status indicates the measurement in progress.
The measurement can be paused at any time using the Pause
function on
the screen. Logging continues in the background, but the recorded levels aremarked as invalid and excluded from the averages. As long as PAUSE is active,theicon flashes. Another tap on

will continue the measurement.

The measurement runs continuously until it is stopped. After 24 hours, a newmeasurement file is opened automatically, which follows the previous day's file
without any gaps.
4.1.7.3 Stop measurement

button. The measurement status display switches first to STOPPING, thenPress theSAVING and finally READY.
Depending on how the global SAVE configuration is set, the XL3 saves all levels that are
defined in the measurement, either automatically to the SD card, or with queries (for moredetails, refer to chapter Save).

4.2 Reverberation time
To activate the reverberation time measurement, tap the menu icon at the top left
select "Reverberation time".

and

In its basic version, the XL3 measures the reverberation time in octave bands from 63 Hz to 8
kHz. You can use an omnidirectional loudspeaker with gated pink noise or an impulse soundsource as the sound source. In this case, the broadband level LApk must be greater than 80 dB
to trigger the measurement and to avoid false measurements. The results are determined
either from a drop of 20 dB (T20) or 30 dB (T30).
The Advanced Room Acoustics option extends the range of functions for measuring thereverberation time by:38

4 Measurement Functions
1/3rd Octave band measurements from 5 Hz to 10 kHz,
Simultaneous measurement of T30, T20, T15 and EDT;
Adjustable trigger level;
Parallel audio recording of the decay spectrum;Calculation of the room mean value from a series of measurements;
Individual display and optimization of spectral decay curves (planned).
4.2.1 Page selection by means of page key

Use the page key
to toggle between the spectral display, the reverberation time curve
and the tabular values. This switching of the display can also be done during a running measurement.
4.2.2 Page selection via the display
Alternatively, you may slect the desired display (except settings) also with a horizontal swipe on
the touch screen or by typing to the respective icon.

Displays the current spectrum in octave or third octave band resolution. Below the
spectrum you will find the information about the measurement mode and the number of recorded measurement cycles.
Shows the averaged reverberation time spectrum of all measurements of the current measurement series.
Here you will find the tabular values of the current or the last measurement performed.
Tapping this icon takes you to the parameter page (not integrated in the page scrolllist). Here you can set all settings of the reverberation time measurement and activate a measurement series if required.

39

4 Measurement Functions
4.2.2.1 Spectral display
Here the spectrum of the current level is displayedin the selected resolution (octave or third octave
bands).
In the dark bar below the spectrum, the current,
unweighted level of the yellow colored band
appears, which you can select using the arrow

keys

and

.

The blue field at the very bottom shows the measurement status. By tapping theicon, you canpause the measurement in progress (Pause); in
this state, the icon flashes. By tapping again, theXL3 is ready for the next measurement.

4.2.2.2 Reverberation time graph
As soon as an initial measurement of the reverberation time has been performed, the device displays the spectral mean values. The single resultof the yellow marked band appears below - you
can select it with the arrow keys.
By tapping the DECAY field, another arrow menu
opens, with which the individual measurements
can be visualized.
Bands with measurement errors are marked withan X above the bar in the respective measurements.
In this FW version it is not yet possible to delete single measurements.

40

4 Measurement Functions
4.2.2.3 Reverberation time table
In this table, those measurement results appear
which you have selected during configuration.
By tapping on "Decay" you can call up the values
individually (e.g. 5/6) or averaged (AV).
If an error or impairment has occurred during ameasurement, a warning message appears
before the corresponding measurement result.
The respective explanation of these abbreviations
can be found below the measurement table.

4.2.3 Perform reverberation time measurement
Place the XL3 in the room according to the standards and install the source for the sound signal(e.g. DS3 dodecahedron loudspeaker). The measuring device must not be in the near field of
the source, otherwise measurement errors will occur. Also note that measuring reverberation
time at low frequencies can be problematic because it is difficult to get enough energy into theroom in the lower bands. In addition, the decay spectra are subject to statistical fluctuations,which is why several measurements should always be recorded and averaged.
In larger rooms, the standards require that both the signal source and the measuring device beplaced successively in several locations in the room. Again, it is recommended to perform several measurements at each location and to average the results, which are then again includedin the averaging of several measurement positions. The XL3 supports this procedure with the"Measurement series" function. See Configure reverberation time measurement.
At the end of the measurement, the XL3 then automatically generates the measurement reportas a TXT file. All individual or all sound level measured values are stored.
4.2.3.1 Select project folder
Select the project folder in which all measurements of this room will be saved under the main
menu with.

41

4 Measurement Functions
Tap at the bottom left under Drive to select thedesired storage and then define the folder where
you want to store the results.
In the bar graph below you can see the occupied
space of the selected media.
4.2.3.2 Configure reverberation time measurement
Here you can set or adjust various parameters and settings for your reverberation time measurement.
If necessary, stop the current measurement to change the parameter(s).

Selectable parameters (base version):
Calculation basis: T30 or T20 (i.e. the reverberation time T is derived from the 30 dB or
20 dB values).
Fixed settings:
1/1 Octave spectral resolution;
80 dB trigger level (i.e. the minimum level
required to enable triggering).

42

4 Measurement Functions
Selectable parameters, available with the Sound
Insulation option:
Calculation basis: T30 or T20 (i.e. the reverberation time T is derived from the 30 dB or
20 dB values);
Spectral resolution: 1/1 Octave or 1/3rd
Octave.
Fixed setting:
80 dB trigger level (i.e. the minimum level
required to enable triggering).

Selectable parameters, available with theAdvanced Room Acoustics option:
Calculation basis: T30, T20, T15 and/or
EDT;
Spectral resolution: 1/1 Octave or 1/3rd
Octave;Min. trigger level: adjustable from 50 to 100
dB. This is the minimum signal level required
for triggering a reverberation time measurement;
Parallel audio recording (of the sound drop):
off or on;
Recording of a measurement series*: off oron.

*Please note that in a room you can measure the reverberation time in two ways:
a. In a Single measurement, both the sound source and the measuring device are each ata defined position in the room and are not moved during the measurement - which typically comprises several measurement cycles;43

4 Measurement Functions
b. A Measurement series links the results of several individual measurements together.
Between every two individual measurements, the sound source and/or the measuring
device are moved to a new position. The XL3 stores the respective results of the individual measurements performed and shows these results individually or as a total average value on the display at the end.
4.2.3.3 Perform reverberation time measurement
Place the sound signal source (e.g. DS3 dodecahedron loudspeaker) and the XL3 in the roomin accordance with the standards. Make sure that the measuring device is not in the near fieldof the sound source, otherwise measurement errors will occur. Also note that you usually needto record and average several measurement cycles per measurement position, since decay
spectra are subject to statistical fluctuations, especially at low frequencies.
For larger rooms, the standards require that both the sound source and the measuring device
be placed sequentially at different locations. Again, it is recommended to record several measurement cycles at each location. From the averaged results of these measurement positions,the overall result of the reverberation time of the room is finally obtained. The XL3 supports thisprocedure with the "Measurement series" function(see Configure reverberation time measurement).
At the end of a single measurement or a series of measurements, the XL3 automatically generates a measurement report as a TXT file with all individual or the total measured value.
Single measurement

key - the instrument is now ready for theStart a single measurement by pressing thefirst measurement cycle. Next, activate the noise source or actuate the impulse sound source
so that the generated sound level is above the trigger threshold.
As soon as the sound source is muted, the XL3 automatically detects the decay of the soundlevel and measures the decay curves in each frequency band. The XL3 indicates those frequency bands, in which a valid measurement has been completed, with a tick in the spectrum
display.
Each further switching on/off of the noise source or triggering of the pulse source automaticallytriggers another measurement cycle, the results of which are averaged with the previous ones.
You can switch between the different displays at any time during the measurement without affecting the measurement itself.

Presslast to complete the single measurement and save the averaged results in an
ASCII text file on the device.
Measurement series

The term "series of measurements" refers to a series of individual measurements at different
points in space that are combined to produce a common result. Thus, several individual meas-

44

4 Measurement Functions
urements are made at different locations in the room and their results are averaged to produce
an overall reverberation time result.
The measurement series must be activated in the Configure reverberation time measurement.
After that, the START Series icon appears in the measurement displays.
By tapping the START Series button, you start
the measurement series and select the storage
location.

Next, press thepress thebutton to begin the first individual measurement. Once you are done,

button and confirm saving the results. Now, move the sound source or the

analyzer, respectively, to the next position in the room and press thesecond measurement, or end it by pressing on

button to start the.

Continue in this manner until you have made therespective individual measurements at all soundsource / meter locations.
After completing the last individual measurement,
tap the END Series button to end the measurement
series and save the averaged overall result of therecorded individual measurements.
Now you can select and view the results of the individual measurements (e.g. "2/4") as well as the averaged total value ("AV") by tapping on "Pos #".

4.2.3.4 Measurement file
Below you can see another example of a file with the results of a reverberation time measurement series. The formatting of this file is such that it can also be imported into MS EXCEL.

45

4 Measurement Functions

4.3 Sound insulation
The XL3 supports the measurement of sound insulation, i.e.:
Airborne sound insulation;
Impact sound insulation (planned);
Facade sound insulation (planned).
Activate this measurement function by tapping the menu iconin the upper left corner andthen "Soundproofing". The instrument supports the continuous recording and display of thevarious individual measurements required to determine the desired sound attenuation.
4.3.1 Measurement sequence & page selection
To determine the sound attenuation, first place the noise source in the transmitting room, andthen measure in both the transmitting and receiving rooms those parameters that are necessary for calculating the result. For this purpose, the XL3 shows on the display either the necessary settings, or the sound level spectrum in the transmitting or receiving room, i.e.:
L1: Level in the transmitter room;
L2: Level in the receiving room;46

4 Measurement Functions
B2: Background level in the receiving room;
T2: Reverberation time in the reception room.
To select the desired page, tap the corresponding button at the top right of each page.
On the "Settings" page you can make the following
settings:
Standard: ISO16283;
Type: Airborne sound;
Speaker positions: 1, 2, 3 or 4;
Results of interest: D, Dn, DnT and/or R';
SLM measurement duration: 6, 15, 30 or 60
seconds;
RT Mode: T20 or T30;
RT min. Trigger level: 80 dB.
Select the appropriate settings
before starting the measuring procedure!

On the "Select measurement" page, you canselect the measurement to be performed next.
Transmitting room: L1-x = position of thenoise source in the transmitting room (number of available positions depends on theabove-mentioned Setting off);
Receiving Room:
L2-x = measuring position in the receiving room (number of available positions
depends on the above-mentioned setting off);
B2 = Background sound level in thereceiving room;
T2 = Reverberation time in the receiving room.
Results: D, Dn, DnT or R';
Settings: Return to the "Settings" page (seeabove).

47

4 Measurement Functions

If you now tap e.g. on, the page with thecurrent sound level spectrum in octave band resolution appears.
In the dark bar below the spectrum, the current,
unweighted level of the yellow colored band
appears, which can be selected using the arrow

keys

and

.

Furthermore, you can tap the button
atthe bottom right at any time to view the results
measured up to that point or their average value"AV".

Place the noise source in the transmitter room at
position #1 and tap the button
measurement cycle.

to start the

Put on suitable hearing protection
before switching on the soundsource!

48

4 Measurement Functions
Switch on the noise source (e.g. dodecahedron
loudspeaker DS3) and move to the desired measurement position. Now press the
key to start
the first measurement and wait until it is completed.
Move to the next measurement position and press
thekey again to start the second (or third,etc.) sound level measurement in the transmitterroom.
Once you have taken enough individual measurements for L1-1, press thekey.

Now go to the L2 receiving room and selecton the "Select measurement" page.
Turn on the sound source (still located at position#1 in the transmitting room) and press the

button to start the first sound level measurement in the receiving room.
Then carry out the other measurements in thereceiving room for data set L2-1 and finally press

the

key.

49

4 Measurement Functions

Selecton the Select Measurement page
and place the noise source in the transmitter roomat position #2.
Repeat the above Measurements in the transmit
and receive room for noise source position #2.
Continue in this manner until you have completed
all L1-x and L2-x measurements for the various positions of the noise source in the transmitter room.
Now place the dodecahedron loudspeaker in thereceiving room to determine the reverberation timeT2.
Selectpage.

on the "Select measurement"Press
to start the reverberation timemeasurement and switch the speaker On and Off
again several times.

Then press50.

4 Measurement Functions
Finally, measure the background sound level B2 inthe receiving room (i.e. with the noise source
switched off).
To do this, selecton the "Select meas-

urement" page and press thekey.

End the measurement series by first pressing the

key and then tapping.

Now you can view the measurement results D, Dn,
DnT or R' individually by tapping the corresponding
button under "Results".
NOTE: At any time during an ongoing measurement series, you can view how many individual
measurements have been performed in the transmitting or receiving room at the various positions of
the sound source on the "Select measurement"
page.

51

5 Data transfer

5 Data transfer
XL3 offers several ways to transfer the stored measurement data:

5.1 MTP (Media Transfer Protocol) over USB-C
The instrument is connected directly to the computer using a USB cable. The instrument thenacts like a thumbdrive and folders and files can be accessed directly with drag and drop.
Please note that software running on the computer cannot directly access the
instruments data via the MTP protocol. Therefore, copy the measurement data
to your computer prior accessing them by SW.
MTP is not supported by MacOS.

5.2 Remote access via XL3 website
You will find detailed instructions on how to activate the web server and how to transfer thedata of the XL3 in this mode to your PC at Remote control via web server.

5.3 SFTP accessFree choose any of the availble sFTP Client software like WinSCP, FileZilla or WatchFTP foraccessing the stored measurement data. The neccessary parameter are:Parameter
File Protocol
Target address
Port
User
Password

Value
SFTP
IP-addresse of the XL3
22
sftp
Password of the WebServers

If you are accessing the instrument via NTi Connect, the parameter are:Parameter
File Protocol
Target address
Port
User
Password

52

Value
SFTP
connect.nti-audio.com
22
Connect key (XXXXX-XXXXX)
Password of the WebServers

6 How to connect a router or gateway

6 How to connect a router or gateway
A router can be connected directly to any USB port of the XL3 if it supports the NDIS protocol.
The Teltonika router TRB140 suits this application very well.
Routers, like the Teltonika RUT240, not supporting NDIS protocol, shall be connected via an
Ethernet connection using a recommended USB to Ethernet adapter.
Please note that the Teltonika gateway TRB140 cannot be operated in USA,
Japan and China due to missing approvals. Alternatively you may then use theTeltonika RUT240 router as it has worldwide approvals.

53

7 Remote control via web server

7 Remote control via web serverOnce you have activated the internal web server, you can connect your XL3 to the Internet andboth remotely control the device and download measurement data during operation.

7.1 Activate the web server
Under System Settings and Connections (described under Commissioning), setting an individual password enables the web server.
To access the XL3 via a network, there must be an active network connection () and the web server must be active. The LED can be yellow, blue or
white.
After that, you can remotely control the XL3 from any HTML-enabled device.

7.2 Response of the device in the internal network
If the meter is connected in the same sub-net as the query computer, you may access themeter via the internal IP address, since in this case there is no firewall in between.
Select your preferred web browser (e.g. Chrome, FireFox or Edge) and type in the IP
address (e.g. 192.174.xxx.xxxx) of the network connection of the XL3. You will find it in
the current network settings of the XL3.

7.3 Addressing the device from an external network
If the device is connected to the Internet somewhere, the internal IP address of the measuring
device is usually not visible, because one or more firewalls are connected in between. In thisconfiguration you may establish connection via the connect.nti-audio.com service that is freeof costs for fair use.

54

7 Remote control via web server
Each XL3 has a unique key that can be used toaddress it from the Internet.
You will find this described under System Settings and Connections in the chapter Commissioning.
The Connect Key is the unique key
to access your XL3 in the cloud.

7.4 Access to NTi Connect service
The NTi Connect service connect.nti-audio.com provides worldwide and secure access to the
webpage, data files and APIs of XL3s.

55

7 Remote control via web server
Open a browser and type connect.nti-audio.com.
A web page opens

Now type in your Connect Key key and click connect.
XL3 uses port 22 to communicate to the NTi Connect Server.

The NTi Connect Server now creates the connection via the server and connects your
PC to the device. The XL3 will then automatically provide you with its web server page.
7.4.1 XL3 web server
The web page will prompt you to enter the password previously defined in XL3. After that the overview screen of the web server opens.

You now have direct access to all measurement
data stored in XL3 and can download each individual file.
In the top menu, you can access the live screen of
the meter via SCREEN.

The use of the NTi Connect service requires that all data traffic to and from XL3
is handled via the server. NTi Connect provides free usage for data volumes up
to 2 GB per month. For data consumption beyond this threshold, the download
speed will be reduced. Opting for the "NTi Connect Open Data 365" subscription ensures uninterrupted communication at full speed.

56

7 Remote control via web server
7.4.2 Remote control via the web user interface
You can now control the device remotely with themouse - just as if you were working directly on thedevice. If the screen of the web interface is touchsensitive, you can also use this touch screen forthe operation.
The website is responsive; i.e. it can be scaled as
desired. The
icon scales the device screen to
the maximum screen size. You can exit this modeat any time by pressing ESC on the PC keyboard.

7.4.3 Fair Use Principle for NTi Connect
7.4.3.1 Free Data Volume
Monthly, NTi Audio provides a free data volume of 2 GB to each XL3 device on the Connect
Server (connect.nti-audio.com). Within this data volume, the typical data transfer rate is 1 to 4
MBytes/s as long as any mobile connection does not limit the rate. The consumed data volume
can be found in Connections.
7.4.3.2 Throttling upon Exceeding
Once the data volume is exceeded, the transmission rate of the XL3 is throttled to about 40
KBytes/s. This throttling is lifted on the first day of each new month, and the data volume starts
counting anew.
7.4.3.3 Effects of Throttling
Despite throttling, remote control of the XL3 via the browser remains feasible. Additionally,
downloading reports and short log files continues to function. However, during a download, thebrowser user interface responds only with limitations. Significantly more pronounced limitations occur during the transmission of large log files and audio recordings, as well as whenusing the Streaming API. This may lead to longer waiting times or even timeouts.
7.4.3.4 Recommended Option
To circumvent these limitations, we recommend acquiring the “NTi Connect Open Data 365”
Option. This option removes the throttling of the transmission rate.

57

7 Remote control via web server
7.4.3.5 File Push Service
The File Push Service transfers files directly to the target server. Data usage isn't counted
towards NTi Connect, and there's no throttling applied.
7.4.3.6 Reserved Rights
We reserve the right further to restrict the fair use of the Connect Server.

58

8 Options and accessories

8 Options and accessories
There are a number of accessories for the XL3:
USB-C to LAN adapter, NTi # 600 000 535;
Ever-ready belt pouch, NTi # 600 000 735;
System case, NTi # 600 000 701;
Backpack, NTi # 600 000 706;
Heavy-Duty outdoor case, NTi # 600 000 704 (IP43) or # 600 000 705 (IP65);
Weather station (see below);
GPS Mouse (see below);
ASD flat ribbon cable for passing closed windows or doors, NTi # 600 000 367.
Specifications and descriptions can be found on the NTi Audio web site.

8.1 Weather station
Connect a weather station to your XL3 to simultaneously record the sound level and weather
data. Depending on the weather station model used, wind speed and wind direction, rain, temperature, air pressure and humidity are documented every 60 s in the log file.
The XL3 supports the following weather stations:Vaisala WXT532 (wind speed, wind direction), NTi # 600 000 736;
Vaisala WXT533 (wind speed, wind direction, rain fall), NTi # 600 000 737;
Vaisala WXT 536 (wind speed, wind direction, rain fall, temperature, air pressure, humidity), NTi # 600 000 738;
LCJ Capteurs LCJ-CV7 SA-SDI_T (wind speed, wind direction).
Connect the weather station to the XL3 either via the USB-A or the programmable digital
input/output interface; it will be recognized & activated, and shown in The status bar,a. After switching ON the XL3;
b. As soon as a sound level measurement with active logging has been started.
If the connection to the weather station is interrupted, the color of the icon in thestatus bar will turn to amber, and instead of the weather data, "-.--" will be written to the log file.
The number of connected weather stations is logged in the "StateOfHealth_
Log.txt" file.

8.2 GPS Mouse
Plug the GPS Mouse to the USB-A connector of the XL3;
Make sure that the LED-side of the GPS Mouse is facing upwards (towards the sky);59

8 Options and accessories
Check the GPS status on the XL3 display:
GPS Mouse is connected and working;
The GPS signal is too weak .
If the GPS Mouse is connected, the received latitude and longitude data is written to the "StateOfHealth_Log.txt" file.

60

9 Calibration

9 Calibration
The XL3 Acoustic Analyzer meets the specifications listed in the XL3 Technical Data.

9.1 Calibration of the measuring device
To ensure that your measuring device meets the published specifications, we recommend anannual calibration of the XL3 together with the measuring microphone. During calibration, thespecifications are checked, differences from the last calibration are pointed out, and the complete frequency response of the microphone is verified.

9.2 Microphone sensitivity calibration
The NTi Audio measurement microphones with ASD functionality include an electronic data
sheet. This allows the XL3 to automatically detect the sensitivity and calibration data of the connected NTi Audio measurement microphone. The electronic data sheet is displayed in the function menu under Calibration.

9.3 Environmental conditions
Prior to calibration, the sound level meter and calibrator should be exposed to stable environmental conditions for the following typical acclimatization periods:
10 minutes after a temperature change of ±10 °C;
15 seconds after a 5 kPa change in ambient static air pressure;
10 minutes after a change of the relative humidity by 30% without condensation.
The calibration procedure and correction data apply within these environmental conditions:Temperature: –10 to +50 °C (14 to 122 °F);
Static air pressure: 65 to 108 kPa;
Humidity: 25 to 90 % r.h. without dew points from –10 to +39 °C (14 to 102 °F).
In case of deviating ambient conditions, observe the relative correction values specified in thecertificate of the calibrator.

9.4 Ambient noise
Make sure that during a calibration with a reference level of 94 dB (or 114.0 dB), the ambient
noise level is less than 69 dB (or 89 dB, respectively).

9.5 Calibration screen
Swipe the touchscreen from top to bottom and tap theicon to open the calibration screen.

9.5.1 Calibration menu with ASD measuring microphone connected61

9 Calibration
The blue status message "Detected"
indicates that the connected microphone has been detected and its ASD
data read.
The microphone sensitivity according to
the ASD data sheet.
Visualizes the microphone configurationaccording to the settings
and.
The list allows the selection of any mounted accessories for this microphone.
Select here, whether you are planningfor free-field or diffuse-field measurements. The XL3 then automaticallyselects the appropriate equalization
curve.
Here you can set the nominal calibrator
level (typ. 94.0 or 114.0 dB)
Tap on START to initiate the calibration
process.

9.5.2 Calibration menu without sensor connected
The yellow status message "No ASD"
indicates that no ASD sensor has been
detected.
The last saved microphone sensitivity.
The arrows indicate the sound incidence according to the settings.
Select any accessories that you may
have installed for this microphone fromthe list.
Select here whether you are planningfree-field or diffuse-field measurements.
The XL3 then automatically selects theappropriate equalization curve.
With the calibrator plugged in, you can
set the nominal calibrator level (94.0 or
114.0 dB) here
Press "START" to initiate the calibration
process.

62

9 Calibration
If a microphone without ASD is connected to the
XL3, you may have to erase the ASD-informationfrom the previously connected microphone first.
To do so, connect the non-ASD microphone to the
XL3, andTap on the trash icon (thus, the display
changes to "unknown" – see above).
You may now either a) Manually enter
the Sensitivity of the connected microphone, or b) Start a calibration with asound calibrator.

9.6 Custom calibration
Follow these steps to calibrate the sensitivity of your NTi Audio measurement microphone or
microphone amplifier or other microphone:
1. Enter the Calibrator Level
according to the instructions on your calibrator.
Thereby, please observe the correction values for the calibrator used and your microphone type as described in chapter Free-field correction;
2. Plug the calibrator onto the microphone and switch on the calibrator;
3. Tap

START to start the calibration;

4. The Calibration: Calibration running... window appears and changes to Calibration:
Successfully finished after the calibration has been successfully performed.
9.6.1 Customer calibration - Manual sensitivity adjustment
If no ASD microphone is connected and no calibrator is available, you can also set the sensitivity of the sensor used manually:
1. Tap the field under "Sensitivity"and enter the microphone sensitivity;

2. Select the associated unit (V/Pa, mV/Pa or μV/Pa);
3. Tap OK.
As soon as you reconnect a measuring microphone with ASD functionality, themanually entered level is replaced by the sensitivity stored in the ASD chip.

63

9 Calibration
User Sensitivity
After a manual calibration, the XL3 additionally writes the determined sensitivity
to the ASD chip of the connected NTi Audio measuring microphone, microphone amplifier or ASD adapter. Thus, the newly determined sensitivity is automatically used from this point on.
However, if the measured sensitivity deviates from the factory calibration by±1.5 dB for a Class 1 measurement microphone or by ±3.0 dB for a Class 2
measurement microphone, the XL3 will display the following message: Measured sensitivity too far (xx dB) from factory settings. Check calibrationlevel and microphone!
Contact NTi Audio with the details for repair or calibration if needed.

9.7 Free-field correction
All NTi Audio measurement microphones are free-field equalized measurement microphones.
The irritation of the free-field level, due to the presence of the microphone body in the soundfield, is already compensated for in the microphone.
As sound calibrators operate in the pressure field, the level at the microphone diaphragm differs for 1/2" measurement microphones at the reference ambient conditions.
For most accurate calibration of the microphone sensitivity, the following free-field correction
shall be applied when using a class 1 sound calibrator. The table below shows the target values for a microphone calibration with a sound level calibrator that is adjusted to 94.0 dB, andthe correction values for different configurations.

M2230 / M2340 Configuration
No accessories
ASD cable + windscreen 90 mm
Windscreen 90 mm
WP30 vertically (90°)
WP30 horizontally (0°)

Sound calibrator

NTi CAL200
93.88 / -0.12
93.53 / -0.47
93.69 / -0.31
93.69 / -0.31
93.69 / -0.31

B&K 4231
93.85 / -0.15
93.50 / -0.50
93.66 / -0.34
93.66 / -0.34
93.66 / -0.34

9.7.1 Application example
Configuration:
XL3 + M2340 measurement microphone + WP30 vertically;
NTi Audio CAL200 class 1 sound calibrator with 94.0 dB;
Setting for calibration:
Open the Calibration screen;
Adjust the Calibrator level to 93.69 dB (refer to the table above);
Plug the sound calibrator onto the microphone and turn it ON;
Tap on START and then on OK.

64

Nor 1251
93.85 / -0.15
93.50 / -0.50
93.66 / -0.34
93.66/ -0.34
93.66/ -0.34

9 Calibration
The calibration has been completed successfully.

9.8 Class 1 sound calibrator
The type-approved class 1 sound calibrator is used to check and maintain the correct display ofthe sound level meter when used under normal conditions in accordance with the typeapproval.
9.8.1 Technical details
Type: Larson Davis CAL200, or another type-approved class 1 sound calibrator;
Calibration frequency: 1 kHz (= reference frequency);
Calibrator level: 94.0 dB or 114.0 dB (= reference sound pressure level).
Take the individual calibration value from the calibration certificate of the soniccalibrator.
9.8.1.1 Calibration details
The calibration is to be carried out according to the chapter "Calibration" in this manual.
9.8.2 Accessories
9.8.2.1 Complainant key
The input keypad has no effect on the sound level readings.

65

66

10 Technical data XL3

10 Technical data XL3
All specifications comply with the IEC61672 standard. Further standards – as far as they go
beyond this standard – are listed with the respective items.
Sound levelmeasurement
Calibratableproduct configurationsclass 1XL3 and the M2340 / M2230 measurement microphone builds an
integrating sound level meter with type approval class 1 according
to IEC 61672 and ANSI S1.4.
XL3 with M2340 / M2230 measuring microphone class 1 according
to IEC 61672 and ANSI S1.4;

Product configurationsclass 1

Product configurationsclass 2XL3 with M2211 / M2215 measurement microphone class 1 frequency response according to IEC 61672 and ANSI S1.4.
The specifications given apply to operation with the microphone attachedor detached.
XL3 with M4261 measurement microphone class 2 according toIEC 61672 and ANSI S1.4.
IEC 61672:2014, IEC 61672:2003, IEC 61260:2014, IEC
61260:2003, IEC 60651, IEC 60804;
China: GB/T 3785:2010, GB/T 3241, GB 3096-2008, GB 50526,
GB-T 4959;
Germany: DIN 15905-5, DIN 45657:2014, DIN 45657:2005, DIN
45645-2, optional: DIN 45645-1;

Standards

Japan: JIS C1509-1:2005, JIS C 1513 class 1, JIS C 1514 class 0;
Switzerland: V-NISSG, NAO;
UK: BS 4142:2014, BS 5969, BS 6698;
USA: ANSI S1.4-2014, ANSI S1.43, ANSI S1.11-2014;

Weighting

Level details

International IEC standards have been adapted as European
standards and the letters IEC have been replaced by EN. XL3 iscompliant with these EN standards.
Frequency weighting: A, C, Z (simultaneously);
Time ratings: Fast, Slow, Impulse1 (simultaneously).
Measurement bandwidth (–3 dB): 4.4 Hz – 23.0 kHz;Level resolution: 0.1 dB;
Intrinsic noise: 2.1 μV(Z).

1 Only available with Extended Noise Measurement Option

67

10 Technical data XL3Sound levelmeasurement
XL3 + M2340: 17.4 dB(A) – 138.3 dB @ 42 mV/Pa;
Measuring
range with different microphones

XL3 + M2230: 17.1 dB(A) – 137.8 dB @ 42 mV/Pa;
XL3 + M2215: 25 dB(A) – 153 dB @ 8 mV/Pa;
XL3 + M2211: 21 dB(A) – 144 dB @ 20 mV/Pa;
XL3 + M2914: 6.5 dB(A) – 103 dB @ 320 mV/Pa;
XL3 + M4261: 27 dB(A) – 146 dB @ 16 mV/Pa.
XL3 + M2340: 25 dB(A) – 138 dB | 28 dB(C) – 138 dB @ 42
mV/Pa;

Linear measuring range
according toIEC 61672 /ANSI S1.4

XL3 + M2230: 24 dB(A) – 137 dB | 27 dB(C) – 137 dB @ 42
mV/Pa;
XL3 + M2215: 33 dB(A) – 153 dB @ 8 mV/Pa;
XL3 + M2211: 29 dB(A) – 144 dB @ 20 mV/Pa;
XL3 + M2914: 14 dB(A) – 103 dB @ 320 mV/Pa;

Stabilization
time
Integration
times
Intrinsic noise
typical without
measuring
microphone@ S = 42 mV/Pa

68

XL3 + M4261: 33 dB(A) – 146 dB @ 16 mV/Pa.
< 10 s.
Minimum: 1 second (default) or 100 ms (with Extended Noise
Measurement option);
Maximum: 24 hours.
Frequency weighting A: 5.1 dBA;
Frequency weighting C: 4.1 dBC;
Frequency weighting Z: 8.0 dBZ.

10 Technical data XL3Sound levelmeasurement
SPL actual, Leq, Lmin, Lmax, Lpeak, LE;
Time weighting Fast, Slow;
Broadband, 1/1 Octave and 1/3rd Octave spectral view;
Gliding LAeq and LCeq with selectable time window from 1 second
to 1 hour;
TaktMax according to DIN 45645-1;
Standard functions

All measurement results are simultaneously available;
Logging of all or data or subsets in selectable intervals ≥ 1 second;
Wizard for measuring the correction values for live events of thelevels LAeq, LCeq and LCpeak;
Individual limit values for each sound level displayed;
Recording of compressed audio;
Digital I/O interface for controlling accessories.
Time weighting Impulse;
Level difference LAIeq – LAeq;
Sound exposure level LAE;
Time-graph view;

Functions ofExtended Noise
Measurement
optionPercentiles / levels of the level frequency distribution for broadband
and spectral measurements
Flexible setting from 0.1% to 99.9% with 7 values in parallel
Sampling rate for Fast/Slow weighted values: every 1.3 ms
Wideband: with 0.1 dB class bandwidth, based on Lxy sampling (x= A, C or Z, y = F, S or EQ1”)
1/1 Octave band and 1/3rd Octave band spectrum: in 1.0 dB classwidth, based on Lxy (x = A, C or Z / y = F or S);
100 ms logging of all or data or subsets;
Recording of uncompressed audio.
Compliant with class 1 of IEC 61260:2014 and ANSI S1.11-2014(filter base 10);Octave band display: 8 Hz – 16 kHz;

Spectrum

1/3rd Octave band display: 6.3 Hz – 20 kHz;
Selectable frequency range is displayed together with A/Z wideband level;
Logging of Leq, min, max every 100 ms or 1 s.

69

10 Technical data XL3
Reverberation Time
Conforms with ISO 3382 and ASTM E2235 based on
Schroeder’s backwards integration;
Octave bands results from 63 Hz - 8 kHz;Measurement parameters: T20, T30;
Impulse and gated noise source;
Automatic averaging for each position;
Chart and table representation of results;
Fixed minimum trigger level: 80 dB LAPK;
Warning indicators according to ISO 3382;
Range: 10 ms - 60 seconds;
Minimum reverberation time (typical):< 100 Hz: 0.3 second;
100 - 200 Hz: 0.2 second;> 200 Hz: 0.1 second.
1/3 octave band: 50 Hz - 10 kHz;
T20, T30, T15, EDT simultaneously;With the “Extended
Room Acoustics”
OptionCalculating spatial room average (Measurement Series)
up to 99 positions;
Audio recording (32-bit float);
Adjustable minimum trigger level from 50 to 100 dB
LAPK.

70

10 Technical data XL3Sound Insulation
Determination of airborne, impact and facade sound insulationon the instrument.
Automated data averaging;
Results as chart and table.
Airborne Sound Insulation:
Sound Sources: Speaker.
Standards:
ISO16283-1:2014;
ISO 717-1: 2021;
England/Wales: Approved Document E (2003).
Results:
Dw | Dn,w | DnT,w | R'w;
Spectrum adaption terms C, Ctr;
Impact Sound Insulation:
Sound Sources: Tapping Machine, Rubber Ball;
With the “Sound Insulation” Option

Standards:
ISO16283-2:2018;
ISO 717-2:2020;
England/Wales: Approved Document E (2003).
Results:
With Tapping Machine: L'n,w | L'nT,w;
With Rubber Ball: L'IA,Fmax | L'iA, Fmax,V,T;
Spectrum adaption terms CI.
Facade Sound Insulation:
Sound Sources: Element Loudspeaker, Global Loudspeaker;
Standards:
ISO16283-3:2016;
ISO 717-1: 2021.
Results:
With Element Loudspeaker: Dw | R'45°,w;With Global Loudspeaker: Dls,2m,w | Dls,2m,n,w |Dls,2m,nT,w;
Spectrum adaption terms C, Ctr––.

71

10 Technical data XL3
Calibration
NTi Audio class 1 sound calibrator: M2340 / M2230 / M2215 /M2211: –0.10 dB;
Free-field correction

Windscreen
correction@ 1 kHzNTi Audio class 1 sound calibrator with 1/4" calibrator adapter, type:
ADP 1/4-P:
M4260: +0.10 dB;
M4261: +0.20 dB.
50 mm windscreen: +0.03 dB;
90 mm windscreen: –0.04 dB;
150 mm windscreen: –0.04 dB;
WP30: –0.03 dB.
Recommended calibration interval: 1 year;

Calibration

Microphone calibration with external sound calibrator possible;
Calibration certificate for a new sound level meter is optionally available.

Input / output interfaces
XLR balanced:
Input impedance 200 kΩ;
Audio input

Phantom power: +48 V switchable; with maximum output current of 10 mA according to IEC 61938;
Automatic Sensor Detection (ASD) for NTi Audio measuring
microphones and preamplifier MA230 / MA220;
Internal speech microphone for recording voice memos.
Built-in speaker;

Audio output
USB-A interface
USB-C interface

Headphone socket 3.5 mm stereo; output reference: @ SPL Level
114.0 dBSPL (calibrated microphone) = –12 dBu.
USB Host supporting the devices described below.
USB Device supporting MTP (file access from the PC) and Network (website access from the PC), as well as charging the Li-Ion battery.
Supported devices:
USB-C to LAN adapter, NTi # 600 000 535;

USB devices

4G/LTE gateways with RNDIS protocol;
Mass storage like USB stick, SSD;

MemoryVaisala or LCJ Capteurs weather station (see below).
32 GB micro-SDHC card (default), replaceable, for storing measurement
data in ASCII format, as well as audio data (WAV) and screenshots (PNG)
Supported formats: FAT32 and NTFS

72

10 Technical data XL3
Input / output interfaces
Rechargeable Li-Ion battery:Typ. 3.6 V / 6'000 mAh;
Voltage range: 3.0 – 4.07 VDC (theXL3 limits the charging
voltage to 4.05 VDC, and thus doubles the number of possible
charging cycles);Energy density = 339 Wh/l;
Typical battery life @ 25 °C (77 °F) with microphone M2340:
with display active: >8 h;with display switched off: >12 h.
Operating temperature: –20 to +60 °C (–4 to +140 °F);

Power supply

The XL3 switches OFF automatically as soon as either the battery charge level drops to 0%, or the temperature of the battery
drops below –19 °C (–2.2 °F) or rises above +60 °C (+140 °F).
Before an automatic self-shutdown, the XL3 stops the current
measurement and saves the present results.
Linear external power supply 9 VDC / 2 A:
Range: 7.0 – 17.0 VDC @ minimum 4 W;
Charges Li-Ion battery in operation; charging time from 10% to80%: typ. 140 min;Maximum charging power 15 W.
USB-C supply with 5 VDC / 1.5 – 3 A / 5 W or 15 W according toUSB-C specification release 1.2 is sufficient to operate the XL3 +charge the battery; USB BC1.2 is not supported;
USB-A supply with 5 VDC / 0.5 A (e.g via a USB-A to USB-C
adapter) does not provide sufficient power to supply the XL3.
The XL3 automatically turns back ON and resumes the last active measurement:
a. after an automatic self-shutdown (due to too low charge level), or;Automatic
restartb. after unintentional removal of the battery (while the device was running).
as soon as it is is reconnected to a voltage source (e.g. power supply unitor charged battery).

Weather station
WXT532;
VaisalaLCJ Capteurs

WXT533;
WXT536.
LCJ-CV7 SA-SDI_T.

73

10 Technical data XL3GeneralClock

Real-time clock with own lithium battery; drift < 1.7 s per 24 hrs.
1/4" tripod connection and fold-out stand on rear side;
Display: 480 x 800 pixels, 4.3" IPS;

Mechanics

Entry: 8 buttons, capacitive multitouch-display;
Dimensions L x W x H: 210 x 85 x 45 mm (8.3 x 3.4 x 1.8 ");Temperature
Humidity
Sensitivity tohigh frequency
fieldsElectromagnetic
compatibility
Protection class
ATEX

Weight: 500 g (1.1 lb) including Li-Ion battery.
–10 to +50 °C (+14 to +122 °F).
5 to 90% RH, non-condensing.
Classification group X.

CE according to: EN 61326-1 class B, EN 55011 class B, EN 61000-42 to -6 and -11.
IP51.
For applications in Zone 2 hazardous areas according to IEC
60079;
Compliant with 2014/34/EU.

74

11 Technical data measurement microphones

11 Technical data measurement microphones
11.1 Calibrateable measuring microphones
M2340 class 1 certified with selftest

M2230 class 1 certified

MA230 preamplifier + MC230A MA220 preamplifier + MC230A
microphone capsulemicrophone capsule
Omnidirectional, condenser free-field microphone with continuous
Microphone typepolarization
Classification accordClass 1 certified
ing to IEC 61672 andANSI S1.4½" removable with thread 60UNS2 type WS2F according to IEC
Microphone capsule61094-4
Preamplifier type
MA230
MA220
Self-checkYes
No±1 dB @ 5 Hz – 20 Hz±1 dB @ >20 Hz – 4 kHz
Frequency response±1.5 dB @ >4 kHz – 10 kHz
tolerance typical±2 dB @ >10 kHz – 16 kHz±3 dB @ >16 kHz – 20 kHz
Individual frequency
Freely available as Excel file: register the microphone on my.ntiresponse
audio.com and contact info@nti-audio.com
Frequency range
5 Hz – 20 kHz
16 dB(A)Intrinsic noise typ17 dB(A)ical
137 dBSPL
Maximum sound138 dBSPL
pressure level @ distortion factor 3%, 1kHz
Sensitivity typical @27.5 dBV/Pa ±2 dB (42 mV/Pa)
1 kHz
Temperature coef< –0.01 dB / °C
ficient
Temperature range–10°C to +50°C (+14°F to +122°F)
Influence of air pres0.005 dB / kPa
sure
Influence of humidity< ±0.05 dB(non-condensing)
Humidity
5% to 90% RH, non-condensing
Long-term stability> 250 years / dB
Power supply
48 VDC Phantom power
Power consumption
0.76 mA typical
2.3 mA typical
Scope of delivery

75

11 Technical data measurement microphones
M2340 class 1 certified with selftest

Electronic data sheet
Output impedance
Output connector
Diameter
LengthWeightProtection classNTi Audio #M2230 class 1 certified

NTi Audio ASD according to IEEE P1451.4 V1.0, class 2, Template27
100 Ω symmetricalbalanced 3-pin XLR
20.5 mm (0.8")
154 mm (6.1")
100 g (3.53 oz)
IP51
600 040 230
600 040 050

11.2 Non-calibratable measuring microphones
M2211 frequency
response class 1

IncludesMicrophone
type
Classificationacc. to IEC
61672 andANSI S1.4
Microphone
capsulePreamplifier
type
Self-check

Frequency
response tolerance typical

Individual frequency
response
Frequency
range

76

M2215 for high soundlevels, frequency
response class 1

M4261 class 2

MA220 preamplifier + MA220 preamplifier +M2211 microphone
M2215 microphone
capsulecapsuleM4261 with fixed microphone capsule

Omnidirectional, condenser free-field microphonewith continuous polarization

Electret capsule

Frequency response class 1

Class 2

1/2" removable with thread 60UNS2 type WS2F
according to IEC 61094-4

1/4" fixed mounted

MA220

–

no

no

no
±1 dB @ 5 Hz – 20 Hz+1/–4.5 dB @ 5 Hz – 20
±1 dB @ >20 Hz – 4 kHz
Hz±1.5 dB @ >4 kHz – 10 kHz±1.5 dB @ >20 Hz – 4±2 dB @ >10 kHz – 16 kHz
kHz±3 dB @ >16 kHz – 20 kHz±3 dB @ >4 kHz – 10 kHz±4.5 dB @ >10 kHz – 16kHz
±5 dB @ >16 kHz – 20
kHz
freely available as MS Excel file:register the microphone on my.nti-audio.com and contact info@nti-audio.com
5 Hz – 20 kHz

11 Technical data measurement microphones
M2211 frequency
response class 1

M2215 for high soundlevels, frequency
response class 1

M4261 class 2

Sensitivity typ- 34 dBV/Pa ±3 dB (20 42 dBV/Pa ±3 dB (836 dBV/Pa ±3 dB (16ical @ 1 kHz
mV/Pa)
mV/Pa)
mV/Pa)
Intrinsic noise
21 dB(A) @ 20
25 dB(A) @ 8 mV/Pa
27 dB(A) @ 16 mV/Pa
typicalmV/PaMaximum
144 dBSPL
153 dBSPL
142 dBSPL
sound pressure level @
distortion
factor 3%, 1kHz
Temperature< ±0.015 dB / °C
< ±0.02 dB / °C
coefficient
Temperature–10°C to +50°C (14°F to 122°F)
0°C to +40°C (32°F to
range
104°F)
Influence of air
0.02 dB / kPa
0.04 dB / kPapressure< ±0.05 dB
Influence of< ±0.4 dB
humidity (noncondensing)
5% to 90% RH, non-condensing
Humidity> 250 years / dB
Long-term stability
48 VDC Phantom power
Power supply
2.3 mA typicalPower con1.7 mA typical
sumption
NTi Audio ASD according to IEEE P1451.4 V1.0, class 2, template 27
Electronic
data sheet
100 Ω symmetrical
Output impedance
balanced 3-pin XLR
Output connector
20.5 mm (0.8")
Diameter
Length
150 mm (5.9")
100 g (3.53 oz)
Weight83 g (2.93 oz)
Protection
IP 51
class
NTi Audio #600 040 022
600 040 045
600 040 070

77

12 Technical data microphone preamplifier

12 Technical data microphone preamplifier
MA230

MA220

Microphone preamp- Compatible with 1/2" microphone capsules type WS2F according tolifier
IEC61094-4
Frequency range
1.3 Hz – 49.5 kHz
4 Hz – 100 kHz
Frequency response±0.1 dB, 10 Hz – 20 kHz±0.2 dB
Phase linearity± 5° @ 20 Hz – 20 kHz± 5° @ 20 Hz – 20 kHz
Intrinsic noise typ2.4 μV(A) @ Cin 15 pF
1.6 μV(A) @ Cin 18 pF
ical≙ 9.1 dBA @ 42 mV/Pa≙ 5.6 dBA @ 42 mV/Pa
Maximum output
22 Vpp ≙ 7.78 Vrms ≙ 139.3
21 Vpp ≙ 7.4 Vrms ≙ 138.9
voltagedBSPL @ 42 mV/Pa
dBSPL @ 42 mV/Pa
Contains calibration data
Original NTi Audio sensitivity = 4.9 V/PaElectronic data sheet

Save and read data with XL3 Analyzer

NTi Audio ASD according to IEEE P1451.4 V1.0, class 2,
template 27
Self-check
Yes
No
Individual frequency freely available as Excel file, register the microphone on my.nti-audiresponseo.com and contact info@nti-audio.com±1 dB @ 5 Hz – 20 Hz±1 dB @ >20 Hz – 4 kHz
Frequency response±1.5 dB @ >4 kHz – 10 kHz
tolerance typical±2 dB @ >10 kHz – 16 kHz±3 dB @ >16 kHz – 20 kHz
Frequency range
5 Hz – 20 kHz
Sensitivity typical27.5 dBV/Pa ±2 dB (42 mV/Pa)@ 1 kHz
Temperature coef< –0,01 dB / °C
ficient
Temperature range–10°C to +50°C (14°F to 122°F)
Influence of air pres0.005 dB / kPa
sure
Influence of humidity< ±0.05 dB(non-condensing)
Humidity
5% to 90% RH, non-condensing
Long-term stability> 250 years / dB
Power supply
48 VDC Phantom power
Power consumption
0.76 mA typical
2.3 mA typicalNTi Audio ASD according to IEEE P1451.4 V1.0, class 2, template
Electronic data sheet
27
Output impedance
100 Ω symmetrical78

12 Technical data microphone preamplifier
MA230

Output connector
Diameter
LengthWeightProtection classNTi Audio #MA220balanced 3-pin XLR
20.5 mm (0.8")
154 mm (6.1")
100 g (3.53 oz)
IP51
600 040 200

600 040 050

12.1 Free-field correction
All NTi Audio measurement microphones are free-field equalized measurement microphones.
The irritation of the free-field level, due to the presence of the microphone body in the soundfield, is already compensated for in the microphone.
As sound calibrators operate in the pressure field, the level at the microphone diaphragm differs for 1/2" measurement microphones at the reference ambient conditions.
For most accurate calibration of the microphone sensitivity, the following free-field correction
shall be applied when using a class 1 sound calibrator. The table below shows the target values for a microphone calibration with a sound level calibrator that is adjusted to 94.0 dB, andthe correction values for different configurations.

M2230 / M2340 Configuration
No accessories
ASD cable + windscreen 90 mm
Windscreen 90 mm
WP30 vertically (90°)
WP30 horizontally (0°)

Sound calibrator

NTi CAL200
93.88 / -0.12
93.53 / -0.47
93.69 / -0.31
93.69 / -0.31
93.69 / -0.31

B&K 4231
93.85 / -0.15
93.50 / -0.50
93.66 / -0.34
93.66 / -0.34
93.66 / -0.34

Nor 1251
93.85 / -0.15
93.50 / -0.50
93.66 / -0.34
93.66/ -0.34
93.66/ -0.34

12.1.1 Application example
Configuration:
XL3 + M2340 measurement microphone + WP30 vertically;
NTi Audio CAL200 class 1 sound calibrator with 94.0 dB;
Setting for calibration:
Open the Calibration screen;
Adjust the Calibrator level to 93.69 dB (refer to the table above);
Plug the sound calibrator onto the microphone and turn it ON;
Tap on START and then on OK.
The calibration has been completed successfully.

79

12 Technical data microphone preamplifier

12.2 Diffuse field correction
12.2.1 M4261 1/4" microphone80

Frequency
[Hz]

200

250

315

400

500

630

800

1000

Correction
[dB]

0.00

0.00

0.00

0.00

0.00

0.01

0.01

0.02

Frequency
[Hz]

1060

1120

1180

1250

1320

1400

1500

1600

Correction
[dB]

0.02

0.02

0.02

0.03

0.03

0.03

0.04

0.05

Frequency
[Hz]

1700

1800

1900

2000

2120

2240

2360

2500

Correction
[dB]

0.05

0.06

0.06

0.07

0.08

0.09

0.10

0.11

Frequency
[Hz]

2650

2800

3000

3150

3350

3550

3750

4000

Correction
[dB]

0.12

0.14

0.16

0.17

0.20

0.22

0.24

0.28

Frequency
[Hz]

4250

4500

4750

5000

5300

5600

6000

6300

Correction
[dB]

0.31

0.35

0.38

0.42

0.47

0.52

0.59

0.65

Frequency
[Hz]

6700

7100

7500

8000

8500

9000

9500

10000

Correction
[dB]

0.72

0.80

0.88

0.98

1.08

1.19

1.29

1.40

Frequency
[Hz]

10600

11200

11800

12500

13200

14000

15000

16000

Correction
[dB]

1.53

1.65

1.78

1.92

2.05

2.19

2.36

2.50

Frequency
[Hz]

17000

18000

19000

20000

Correction
[dB]

2.62

2.72

2.79

2.83

12 Technical data microphone preamplifier
12.2.2 M2340 1/2" microphone

Frequency
[Hz]

200

250

315

400

500

630

800

1000

Correction
[dB]

0.00

0.00

0.00

0.01

0.01

0.02

0.03

0.05

Frequency
[Hz]

1060

1120

1180

1250

1320

1400

1500

1600

Correction
[dB]

0.05

0.06

0.06

0.07

0.08

0.09

0.10

0.12

Frequency
[Hz]

1700

1800

1900

2000

2120

2240

2360

2500

Correction
[dB]

0.13

0.15

0.16

0.18

0.20

0.22

0.25

0.28

Frequency
[Hz]

2650

2800

3000

3150

3350

3550

3750

4000

Correction
[dB]

0.31

0.35

0.39

0.43

0.49

0.54

0.60

0.68

Frequency
[Hz]

4250

4500

4750

5000

5300

5600

6000

6300

Correction
[dB]

0.76

0.85

0.93

1.02

1.14

1.25

1.41

1.54

Frequency
[Hz]

6700

7100

7500

8000

8500

9000

9500

10000

Correction
[dB]

1.70

1.87

2.05

2.26

2.48

2.70

2.92

3.13

Frequency
[Hz]

10600

11200

11800

12500

13200

14000

15000

16000

Correction
[dB]

3.38

3.62

2.86

4.11

4.35

4.60

4.88

5.11

Frequency
[Hz]

17000

18000

19000

20000

Correction
[dB]

5.29

5.42

5.49

5.51

81

12 Technical data microphone preamplifier
Measurement uncertainty 63 Hz – 4 kHz ±0.2 dB;
Measurement uncertainty 4 kHz – 20 kHz ±0.3 dB.

12.3 Windscreen corrections
12.3.1 Windscreen 50 mm correction (1/2")

Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction
[dB]

82

200

250

315

400

500

630

800

1000

-0.03

-0.03

-0.03

-0.03

-0.03

-0.03

-0.03

-0.03

1060

1120

1180

1250

1320

1400

1500

1600

-0.03

-0.03

-0.03

-0.03

-0.03

-0.04

-0.04

-0.04

1700

1800

1900

2000

2120

2240

2360

2500

-0.04

-0.04

-0.04

-0.04

-0.04

-0.04

-0.04

-0.05

2650

2800

3000

3150

3350

3550

3750

4000

-0.05

-0.05

-0.05

-0.06

-0.06

-0.06

-0.07

-0.07

4250

4500

4750

5000

5300

5600

6000

6300

-0.07

-0.08

-0.08

-0.09

-0.09

-0.10

-0.10

-0.10

6700

7100

7500

8000

8500

9000

9500

10000

-0.11

-0.11

-0.11

-0.11

-0.11

-0.11

-0.10

-0.08

12 Technical data microphone preamplifier
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction
[dB]

10600

11200

11800

12500

13200

14000

15000

16000

-0.06

-0.04

0

0.04

0.10

0.17

0.28

0.41

17000

18000

19000

20000

0.55

0.70

0.86

1.01

12.3.2 Windscreen 90 mm (1/2")

Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction
[dB]

200

250

315

400

500

630

800

1000

0.02

0.02

0.03

0.03

0.03

0.03

0.03

0.04

1060

1120

1180

1250

1320

1400

1500

1600

0.04

0.04

0.04

0.04

0.05

0.05

0.05

0.06

1700

1800

1900

2000

2120

2240

2360

2500

0.06

0.07

0.07

0.08

0.08

0.09

0.10

0.11

2650

2800

3000

3150

3350

3550

3750

4000

0.12

0.13

0.14

0.15

0.17

0.19

0.21

0.23

4250

4500

4750

5000

5300

5600

6000

6300

0.25

0.28

0.31

0.34

0.37

0.41

0.46

0.5

83

12 Technical data microphone preamplifier
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction[dB]
Frequency[Hz]
Correction
[dB]

6700

7100

7500

8000

8500

9000

9500

10000

0.56

0.61

0.67

0.75

0.82

0.9

0.98

1.05

10600

11200

11800

12500

13200

14000

15000

16000

1.15

1.24

1.33

1.43

1.52

1.63

1.74

1.85

17000

18000

19000

20000

1.93

2.00

2.06

2.09

Measurement uncertainty 63 Hz – 4 kHz ±0.2 dB;
Measurement uncertainty 4 kHz – 20 kHz ±0.3 dB.

12.4 Correction weather protection WP30-90/-150
The following correction data apply for the WP30 weather protection with either 90 mm or 150
mm windscreen.
12.4.1 Horizontal sound incidence (ambient noise)84

Frequency
[Hz]

200

250

315

400

500

630

800

1000

Correction
[dB]

0.00

0.00

0.00

0.01

0.01

0.02

0.04

0.07

Frequency
[Hz]

1060

1120

1180

1250

1320

1400

1500

1600

Correction
[dB]

0.08

0.09

0.10

0.12

0.13

0.16

0.19

0.22

Frequency
[Hz]

1700

1800

1900

2000

2120

2240

2360

2500

Correction
[dB]

0.26

0.31

0.36

0.41

0.48

0.55

0.64

0.74

Frequency
[Hz]

2650

2800

3000

3150

3350

3550

3750

4000

12 Technical data microphone preamplifier
Correction
[dB]

0.86

0.98

1.15

1.29

1.47

1.64

1.81

2.02

Frequency
[Hz]

4250

4500

4750

5000

5300

5600

6000

6300

Correction
[dB]

2.20

2.35

2.48

2.58

2.67

2.73

2.78

2.81

Frequency
[Hz]

6700

7100

7560

8000

8500

9000

9500

10000

Correction
[dB]

2.86

2.94

3.05

3.24

3.43

3.60

3.72

3.79

Frequency
[Hz]

10600

11200

11800

12500

13200

14000

15000

16000

Correction
[dB]

3.82

3.86

3.96

4.22

4.62

5.15

5.79

6.26

Frequency
[Hz]

17000

18000

19000

20000

Correction
[dB]

6.50

6.57

6.55

6.50

Measurement uncertainty 63 Hz – 4 kHz ±0.2 dB
Measurement uncertainty 4 kHz – 20 kHz ±0.3 dB
12.4.2 Vertical sound incidence (e.g aircraft noise)
For 0° vertical sound incidences (e.g. aircraft noise during overflight) no correction is needed.

12.5 Frequency weighting filter

10

A
–70.4

Frequency weighting [dB]
C
–14.3

12.5

–63.4

–11.2

Z
0.0
0.0

16

–56.7

–8.5

0.0

20
25

–50.5
–44.7

–6.2
–4.4

0.0
0.0

31.5

–39.4

–3.0

0.0

40
50

–34.6
–30.2

–2.0
–1.3

0.0
0.0

63

–26.2

–0.8

0.0

80
100

–22.5
–19.1

–0.5
–0.3

0.0
0.0

125

–16.1

–0.2

0.0

160

–13.4

–0.1

0.0

Rated frequency [Hz]85

12 Technical data microphone preamplifier

200

A
–10.9

Frequency weighting [dB]
C
0.0

Z
0.0

250

–8.6

0.0

0.0

315
400

–6.6
–4.8

0.0
0.0

0.0
0.0

500

–3.2

0.0

0.0

630
800

–1.9
–0.8

0.0
0.0

0.0
0.0

1000

0.0

0.0

0.0

1250
1600

0.6
1.0

0.0
–0.1

0.0
0.0

2000

1.2

–0.2

0.0

2500
3150

1.3
1.2

–0.3
–0.5

0.0
0.0

4000

1.0

–0.8

0.0

5000
6300

0.5
–0.1

–1.3
–2.0

0.0
0.0

8000

–1.1

–3.0

0.0

10000
12500

–2.5
–4.3

–4.4
–6.2

0.0
0.0

16000

–6.6

–8.5

0.0

20000

–9.3

–11.2

0.0

Rated frequency [Hz]86

13 Safety instructions

13 Safety instructions
In the following, you will find important information on the safe operation of the device. Readand follow these safety notes and instructions. Keep the instructions for future reference.
Ensure that it is available to all persons using the device.
DANGER! Threats for children
Make sure that plastic covers, packaging, etc. are disposed ofproperly and are not within the reach of babies and small children. Danger of suffocation! Ensure that children do not detachany small parts from the device (e.g. control knobs or similar).
They could swallow the parts and choke on them! Do not allow
children to use electrical equipment unsupervised.
DANGER! Fire, explosion or burn hazard
Do not short-circuit, damage, heat above 80°C, burn or disassemble the battery. Follow the manufacturer's instructions.
Only charge with a suitable charger. 2.4 A maximum charging
current. 4.1 V maximum charging voltage.
NOTE! Operating conditions
The device is designed for indoor use. To avoid damage, never
expose the device to liquids or high humidity. Avoid prolonged
direct sunlight, heavy dirt and strong vibrations.

87