Castle group dBAir User manual

www.castlegroup.co.uk
dBAir Sound Level Meter
Operating Manual
Castle Group Ltd
Salter Road
Scarborough
North Yorkshire
YO11 3UZ, UK
Copyright © Castle Group Ltd 2017
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without the permission of the copyright holder.
Rev B
HB/141/030/EL

Contents
Chapter 1 ..................................................................1
Introduction...................................................................................................................................1
Chapter 2 ..................................................................2
dBAir Models & Features........................................................................................................2
Safety............................................................................................................................................................. 2
Safety Octave ............................................................................................................................................. 2
Environmental............................................................................................................................................ 2
Environmental Octave ............................................................................................................................ 3
Safety & Environmental......................................................................................................................... 3
Safety & Environmental Octave ......................................................................................................... 3
Consultant ................................................................................................................................................... 4
Microphone and Pre-Amplifier ..............................................................................................5
Microphone Types ................................................................................................................................... 5
Microphone Polarisation ............................................................................................................. 6
Microphone Sensitivity ................................................................................................................. 6
Removal of Microphone............................................................................................................... 7
Pre-Amplifier Removal & Fitting ........................................................................................................ 7
Microphone Extension Cable..................................................................................................... 7
Certifiable Calibration............................................................................................................................. 8
Chapter 3 ..................................................................9
Measuring Sound........................................................................................................................9
Incidence Angle......................................................................................................................................... 9
Pressure Field - (meeting ANSI Standards)........................................................................ 9

Free Field - (meeting IEC Standards)...................................................................................... 9
Sound Level –General Advice......................................................................................................... 10
Chapter 4 ...............................................................11
Getting Started ........................................................................................................................11
Keypad Layout ........................................................................................................................................ 11
Powering Your dBAir Sound Level Meter .................................................................................. 12
Instrument Icons ................................................................................................................................... 13
Icon Location.................................................................................................................................. 14
Chapter 5 ...............................................................15
Using Your dBAir .....................................................................................................................15
Real Time.................................................................................................................................................. 15
Recording ................................................................................................................................................. 16
Recording Screen Display........................................................................................................ 17
Time History Disabled...................................................................................................... 17
Time History Enabled ....................................................................................................... 17
Time History Disabled, Duration Timer Set ........................................................... 18
Time History Enabled, Duration Timer Set............................................................. 18
Time History Enabled, Interval Timer Set................................................................ 19
Stopping an Active Recording................................................................................................ 20
Save ......................................................................................................................................... 20
Resume Recording ........................................................................................................... 20
Don’t Save............................................................................................................................. 20
Voice Memo......................................................................................................................... 21
File Review................................................................................................................................................ 22
Time History Disabled................................................................................................................ 22
Time History Enabled ................................................................................................................. 23
Time History Disabled, Duration Timer Set ..................................................................... 24
Time History Enabled, Duration Timer Set....................................................................... 25
Time History Enabled, Interval Timer Set.......................................................................... 26

File Review Options...................................................................................................................... 27
Exit ............................................................................................................................................ 27
Menu ....................................................................................................................................... 27
HPD.......................................................................................................................................... 27
Voice Memo......................................................................................................................... 27
Chapter 6 ...............................................................28
TheCastleCloud Gateway......................................................................................................28
Logging In.................................................................................................................................................. 29
Change Account........................................................................................................................... 30
Connect to dBAir................................................................................................................................... 31
Update Gateway Software ................................................................................................................ 32
Update Instrument Software........................................................................................................... 33
Update Instrument HPD.................................................................................................................... 34
Chapter 7 ...............................................................35
Menu Navigation & Settings...............................................................................................35
Measurement Setup ........................................................................................................................... 36
Function............................................................................................................................................ 37
Full Octave............................................................................................................................. 37
Third Octave......................................................................................................................... 38
Frequencies ............................................................................................................... 38
Short Interval............................................................................................................. 38
Long Interval.............................................................................................................. 38
Upgrade to Octave Band Analysis.............................................................................. 39
Weightings & Range.................................................................................................................. 40
Range...................................................................................................................................... 40
Frequency Weighting....................................................................................................... 40
Time Weighting .................................................................................................................. 40
Results Selection.......................................................................................................................... 41
Exposure .......................................................................................................................................... 42

UK/EU.................................................................................................................................... 42
OSHA (PEL)........................................................................................................................... 43
Custom................................................................................................................................... 43
Upgrade to Exposure....................................................................................................... 44
Data Recording............................................................................................................................. 45
Time History On - Enabled.............................................................................................. 46
Time History On - Disabled ............................................................................................ 47
Short Time Interval ........................................................................................................... 48
Long Time Interval............................................................................................................. 48
Timer Selection................................................................................................................... 49
Smart Timer .............................................................................................................. 50
Duration Timer ......................................................................................................... 51
Interval Timer............................................................................................................ 51
Start On ....................................................................................................................... 51
Statistics.......................................................................................................................................... 52
Percentiles............................................................................................................................ 53
Show LN < 5 Minutes ...................................................................................................... 53
Lden......................................................................................................................................... 54
Upgrade to Statistics....................................................................................................... 55
Audio Recording........................................................................................................................... 56
Voice Memo......................................................................................................................... 57
Start .............................................................................................................................. 57
End ................................................................................................................................. 58
Off ................................................................................................................................... 59
Event Recording ................................................................................................................. 61
Quality........................................................................................................................... 61
Record Method ........................................................................................................ 62
Continuous (Cont) ........................................................................................... 62
Trigger (Trig) ..................................................................................................... 62
Trigger Edge............................................................................................... 63
Trigger Level............................................................................................... 63
Trigger Freq ............................................................................................... 64
Record Time............................................................................................... 64
Amplify Noise Events.............................................................................................. 65

Upgrade to Event Recording.............................................................................. 65
Save as Template ........................................................................................................................ 66
File Manager ........................................................................................................................................... 67
Load File ........................................................................................................................................... 68
Filter Selection .................................................................................................................... 68
Send Files To Cloud..................................................................................................................... 69
Filter Selection .................................................................................................................... 70
Clear Cloud File Queue .............................................................................................................. 71
Delete File........................................................................................................................................ 72
Delete All Files ............................................................................................................................... 73
Auto File Naming.......................................................................................................................... 74
Auto File Review............................................................................................................................ 75
Save CSV File ................................................................................................................................. 75
Template Manager............................................................................................................................... 76
Load Template .............................................................................................................................. 76
Create Template .......................................................................................................................... 77
Edit Template................................................................................................................................. 78
Delete Template........................................................................................................................... 79
Save Current Setup .................................................................................................................... 80
Hearing Protection............................................................................................................................... 81
Best Available Method............................................................................................................... 82
Octave Method.............................................................................................................................. 82
HML Method.................................................................................................................................. 84
SNR Method .................................................................................................................................. 86
Settings ............................................................................................................................................ 88
HSE Correction................................................................................................................... 88
Standard Deviation ........................................................................................................... 88
Upgrade to Hearing Protection............................................................................................. 89
Instrument Setup.................................................................................................................................. 90
Wi-Fi................................................................................................................................................... 91
WiFi Networks .................................................................................................................... 92
Network Settings............................................................................................................... 93
Screen............................................................................................................................................... 94
Brightness ............................................................................................................................ 94

Screen Colour ..................................................................................................................... 94
Auto Dim................................................................................................................................ 95
Enable Screen Shot .......................................................................................................... 95
Date.................................................................................................................................................... 96
Time ................................................................................................................................................... 96
Language......................................................................................................................................... 97
Information ..................................................................................................................................... 97
SPL Bar Levels.............................................................................................................................. 98
USB Drive ........................................................................................................................................ 99
Support.......................................................................................................................................... 100
Calibration ............................................................................................................................................. 101
Cal Value (dB) ............................................................................................................................. 101
Cal History.................................................................................................................................... 103
Send History To Cloud ............................................................................................................ 103
Startup Options................................................................................................................................... 104
Calibration Reminder .............................................................................................................. 104
Calibrate Instrument ............................................................................................................... 104
Chapter 8 ............................................................105
Measurement Screens ......................................................................................................105
Measurements ................................................................................................................................... 105
Measurements Table....................................................................................................................... 107
Exposure................................................................................................................................................. 108
Percentiles (LN).................................................................................................................................. 109
Lden.......................................................................................................................................................... 110
1/1 Octave............................................................................................................................................ 111
1/3 Octave............................................................................................................................................ 112
Chapter 9 ............................................................113
Accessories.............................................................................................................................113

1
Chapter 1
Introduction
Thank you for purchasing a dBAir from Castle Group Ltd.
Your new Sound Level meter is at the forefront of design and technology yet has been
developed for seamless intuitive operation without the unnecessary complexity of
traditional sound level meters.
It boasts a high resolution large colour LCD with simple and clear visual data
representation, has advanced data recording capabilities which records your data to
the large internal memory available at your disposal.
Equipped with a simple plug in microphone pre-amplifier, carry strap and a responsive
membrane keypad all housed in an elegant, perfectly sized, balanced and practical case
which has been developed specifically with this in mind.
Every model of the dBAir sound level meter has inbuilt Wi-Fi allowing you to automatically
upload your recordings to our simple to use in-browser software at
TheCastleCloud.com. Your data here is secure, always available and backed up
automatically.
Equally, the dBAir can also be connected to The Castle Cloud through a PC app called
the Castle Gateway, which enables you to upload your recordings via your PC using the
included Micro USB Cable and your PC’s internet connection. You can also update your
instruments software as and when required. An alert in The Castle Cloud will inform you
when updates are available.
Not only that, your dBAir sound level meter can act as a USB drive allowing you access
to your saved recordings and transfer the standard format .csv recorded files so you
can open them in your favourite spread sheet application and create your own reports.
Welcome to the new era in sound level measurement.

2
Chapter 2
dBAir Models & Features
A list of dBAir models and features are listed below. The dBAir models are presented
with all of the required features to fulfil specific applications where noise measurement
is a requirement, such as for Safety or Construction.
Safety
dBAir Safety (GA141S)
LSPL, LEQ, LMIN, LMAX, LPEAK, LEP’d, Exposure Points, Dose
Hearing Protector Calculator
Voice Memo Recording
Safety Octave
dBAir Safety Octave (GA141SO)
LSPL, LEQ, LMIN, LMAX, LPEAK, LEP’d, Exposure Points, Dose
Octave Band Analysis (1/1): LSPL, LEQ, LMAX, LMAX, LPEAK
Hearing Protector Calculator
Voice Memo Recording
Environmental
dBAir Environmental (GA141E)
LSPL, LE, LEQ, LMIN, LMAX, LPEAK
Statistical Parameters: LTM3, LTM5, Lday, Levening, Lnight, Ldn, Lden, NA, 10 user-definable
Ln values (L1- L99, 0.1dB resolution)
Voice Memo Recording
Noise Event Recording

3
Environmental Octave
dBAir Environmental Octave (GA141EO)
LSPL, LE, LEQ, LMIN, LMAX, LPEAK
Statistical Parameters: LTM3, LTM5, Lday, Levening, Lnight, Ldn, Lden, NA, 10 user-definable
Ln values (L1- L99, 0.1dB resolution)
Octave Band Analysis (1/1 or 1/3 Octaves): LSPL, LE, LEQ, LMAX, LMAX, LPEAK, Ln’s.
Voice Memo Recording
Noise Event Recording
Safety & Environmental
dBAir Safety & Environmental (GA141SE)
LSPL, LEQ, LMIN, LMAX, LPEAK, LEP’d, Exposure Points, Dose
Statistical Parameters: LTM3, LTM5, Lday, Levening, Lnight, Ldn, Lden, NA, 10 user-definable
Ln values (L1- L99, 0.1dB resolution)
Hearing Protector Calculator
Voice Memo Recording
Noise Event Recording
Safety & Environmental Octave
dBAir Safety & Environmental Octave (GA141SEO)
LSPL, LEQ, LMIN, LMAX, LPEAK, LEP’d, Exposure Points, Dose
Statistical Parameters: LTM3, LTM5, Lday, Levening, Lnight, Ldn, Lden, NA, 10 user-definable
Ln values (L1- L99, 0.1dB resolution)
Octave Band Analysis (1/1 or 1/3 Octaves): LSPL, LE, LEQ, LMAX, LMAX, LPEAK, Ln’s
Hearing Protector Calculator
Voice Memo Recording
Noise Event Recording

4
Consultant
Professional configuration, choose from the parameters listed below.
dBAir Consultant (GA141X)
Standard:
•LSPL, LE, LEQ, LMIN, LMAX, LPEAK
•Voice Memo Recording
Options:
•Exposure: LEP’d, Exposure Points, Dose
•Statistics:
LTM3, LTM5, Lday, Levening, Lnight, Ldn, Lden, NA, 10 user-definable Ln values (L1-
L99, 0.1dB resolution)
•Octave Band Analysis (1/1)
LSPL, LE, LEQ, LMAX, LMAX, LPEAK, *Ln’s
•Octave Band Analysis (1/3)
LSPL, LE, LEQ, LMAX, LMAX, LPEAK, *Ln’s
•Hearing Protector Calculator
•Noise Event Recording
* where Statistics option fitted

5
Microphone and Pre-Amplifier
Measurement microphones by the very nature of their manufacture are precision
components that are easily damaged through incorrect use. Great care must be taken
when using the instrument to ensure the longevity of the microphone.
Microphone Types
Three different types of microphone are manufactured, and each is designed for
measuring noise in different applications which is out of the scope of this manual. Each
one however, has a different sound incidence angle. The sound incidence angle
determines the angle the dBAir sound level meter is held relative to the actual noise
source being measured.
Free Field
Sound Incidence Angle = 0°
Point the sound meter directly towards the noise source
Pressure Field
Sound Incidence Angle = 90°
Point the sound meter at 90° to the noise source
Random Incidence Field
Point the sound meter at approximately 70° to the noise source
To comply with legislation all dBAir sound level meters outside of the US are
supplied with a Free Field measurement microphone, and a Pressure Field
measurement microphone within the US

6
Microphone Polarisation
Microphones require a polarisation voltage to operate and are manufactured in two
ways.
Externally Polarised
These microphones require an external charge for the microphone to operate which is
generally 200V and supplied by the sound level meter.
Pre-Polarised
These microphones generate the polarisation voltage internally and do not require the
externally generated 200V polarisation charge.
All microphones supplied with dBAir sound level meters are Pre-Polarised.
Microphone Sensitivity
The sensitivity of a microphone is determined by the output voltage it produces for a
defined sound source.
Microphones are manufactured with numerous sensitivity levels and operate within a
specified tolerance. Different microphones of the same model may therefore give slight
differences in readings when used on the same sound meter. To allow for this all dBAir
sound level meters have been designed to accommodate any variations in the tolerance
of the supplied microphone up to ±3dB.
All models of the dBAir sound level meter with Class 1 approval have been designed for
microphones with a sensitivity of 50mV/Pa.
All models of the dBAir sound level meter with Class 2 approval have been designed for
microphones with a sensitivity of 25mV/Pa.
Great care must be taken to ensure the microphone and sound meter sensitivities
match otherwise incorrect readings will occur.

7
Removal of Microphone
The microphone is fitted to the pre-amplifier by screwing the microphone in a clockwise
direction ensuring that the pre-amplifier spring pin is located centrally in the
microphone.
To remove the microphone, unscrew in an anti-clockwise direction.
The microphone has a protection grid which can also be unscrewed and removed, great
care must be taken to ensure that this is NOT removed. Underneath the protection
grid is the microphone diaphragm which should never be touched or be subject to dust
or dirt. Doing so may damage the microphone beyond repair or affect its acoustic
response dramatically.
Pre-Amplifier Removal & Fitting
To attach the pre-amplifier, position the RED orientation key on the pre-amplifier with
the RED identification mark on the dBAir sound level meter and gently push the pre-
amplifier into the connector.
To remove, gently pull the pre-amplifier stem away from the instrument body.
To prevent damage occurring to your dBAir sound level meter or your
Pre-Amplifier assembly never attempt to twist the pre-amplifier.
Microphone Extension Cable
To attach the microphone extension cable (purchased separately), position the RED
orientation key on the extension cable connector with the RED identification mark on
the dBAir sound level meter and gently push the extension cable into the connector.
To fit the pre-amplifier to the extension cable, see Pre-Amplifier Removal & Fitting
above.
To remove, gently pull the extension cable connector by pulling on the knurled part of
the stem.

8
Certifiable Calibration
The calibration process includes the microphone, pre-amplifier and sound level meter.
Any change in this measurement chain will require a new calibration certificate.
Castle Group Ltd offers a complete calibration service offering either a full UKAS
calibration or a standard traceable calibration which can be supplied with or without a
test report.
It is recommended that your sound meter instrumentation is calibrated annually to
ensure your measuring equipment is completely accurate and fully compliant.

9
Chapter 3
Measuring Sound
Always calibrate your dBAir sound level meter prior to and after taking measurements
using a known sound source, such as the Castle GA607 Sound Level Calibrator.
Your dBAir can be set for calibration immediately after the unit has been turned on, see
Startup Options for further details.
Incidence Angle
It is essential that you hold your dBAir sound level meter at the correct angle to the
noise source depending on the microphone type supplied with your meter.
The type of microphone supplied with your instrument will either be Free Field or
Pressure Field, see below for details of the measuring incidence angle for each
microphone type: -
Pressure Field - (meeting ANSI Standards)
Pressure Field microphones required incidence angle of 90°, therefore whilst
measuring ensure your dBAir sound level meter is at 90° relative to the noise source
being measured.
Free Field - (meeting IEC Standards)
Free Field microphones require an incidence angle of 0°, therefore whilst measuring
always point your dBAir sound level meter directly towards the noise source being
measured.
To comply with legislation all dBAir sound level meters outside of the US are
supplied with a Free Field measurement microphone, and a Pressure Field
measurement microphone within the US

10
Sound Level –General Advice
In some environments, high levels of noise can occur. The Castle dBAir sound level
meter has therefore been designed for complete accuracy up to sound levels of 140dB.
Before you record measurements, take the time to ensure you have chosen the
optimum range for the process to be recorded. Wherever possible, the optimum range
is when the average measured signal is approximately half way between the top of the
range and the bottom of the range without an overload condition.
Where high levels of noise are encountered, the meter may register an overload and in
these circumstances the meter will display that this has occurred, it is therefore
advisable to determine if an overload occurs on the selected range. In such cases, you
will need to select a higher range to accommodate the higher peak levels. See Technical
Specifications for peak range limits on each individual range.
If the noise levels are too low for the range selected, then the meter will display an under
range condition. Under these circumstances, you will need to select a lower range.
For more detailed information, see Overload and Under Range Conditions and
Measuring Ranges.
If measuring low level noise, then be aware of the inherent noise levels caused by a
combination of thermal and electrical noise from both the microphone and the sound
level meter. Measuring data that lies within 10dB of the lowest quoted level on the
lowest measuring range may be influenced by the self-noise of the system. See
Technical Specifications for inherent noise levels and range limits.

11
Chapter 4
Getting Started
This user manual is written for all models of the dBAir sound level meter. Some
parameters and features may not be available for your specific model.
Please review your model in the dBAir Models & Features to determine which
parameters and features are available where required.
Keypad Layout
All models of the dBAir sound level meter have the same keypad layout and operation.
Soft Key 2
Soft Key 1
Directional Keys:
Up, Down, Left,
Right
Power,
Reset or Screen Grab
OK, Record, Stop

12
Powering Your dBAir Sound Level Meter
Your dBAir sound level meter can be powered from four 1.5V AA size batteries, four
1.2V rechargeable batteries or via the micro USB connector via a USB port or power
supply capable of delivering 0.5A.
The battery compartment is located at the rear of your sound meter, remove the
battery door and insert the batteries using the correct polarity which is clearly shown
where the batteries are located.
Replace the battery door securely before using the instrument.
Whilst powering the instrument using the USB cable, you may be shown a screen to
activate the USB drive: -
This is not required to power the unit, press Soft Key 2 labelled Disable within 5
seconds to ensure the instrument does not enter USB drive mode. This option can be
disabled, see USB Drive for more information.
In all power configurations press the Power Key once to switch the instrument on. The
instrument will take several seconds to boot and load configuration settings.
To switch the instrument off, hold the Power Key down for two seconds and follow the
on-screen instructions, note that if no key is pressed within two minutes of switching
the sound level meter on then the unit will automatically power down.