Cirrus Research Optimus+ VNK User manual

Quick Start Guide
Opmus+ VNK
Using the VNK to take vehicle
noise measurements

Optimus VNK - Quick Start Guide Taking Vehicle Noise Measurements With The VNK
23
Copyright
Copyright © Cirrus Research plc 2010-2019
All rights reserved.
You may re-use this document/publicaon (not including the Cirrus Research plc logo and
other product logos) free of charge in any format for research, private study or internal
circulaon within an organisaon. You must re-use it accurately and not use it in a misleading
context.
You must not modify text, images or illustraons in any way. The material must be
acknowledged as Cirrus Research plc copyright and you must give the tle of the source
document/publicaon.
Where any third-party copyright material is idened you will need to obtain permission
from the copyright holders concerned.
Trademarks
Cirrus Research plc, the Cirrus Research plc Logo, doseBadge, DOSEBADGE, Opmus, the
NoiseTools Logo and the Noise-Hub Logo are either registered trademarks or trademarks of
Cirrus Research plc in the United Kingdom and/or other countries. Microso and Windows
are registered trademarks of Microso, Inc. The Bluetooth® word mark and logos are
registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by Cirrus
Research is under license. Other trademarks and trade names are those of their respecve
owners.
Updates
In the interests of connuous product improvement, Cirrus Research plc reserves the right
to make changes to product specicaons without noce.
To learn about the latest updates that have been implemented into this product and to
download the most current version of this user manual, visit our website at
www.cirrusresearch.co.uk
Version 2 Q1 2019
About this quick start guide
• The instrucons in this user manual refer to the operaon of Cirrus Research plc
Opmus+ sound level meters with version 5.0 or higher of the rmware
• Where the terms ‘Opmus+’ or ‘Opmus’ are used, it refers to all variants within
the Opmus+ range of instruments, including the Opmus+ Yellow (CR:150 series),
Opmus+ Red (CR:160 series), Opmus+ Green (CR:170 series) and Opmus+ Purple
(CR:190 series)
• Full technical details for the Opmus+ range of instruments can be found on the Cirrus
Research website at www.cirrusresearch.co.uk/library/datasheets/
• For full operaonal instrucons, please consult the instrument handbook that was
supplied with your Opmus+

Optimus VNK - Quick Start Guide Taking Vehicle Noise Measurements With The VNK
45
1 SenguptheOpmusVNK
Contents
1. Seng up the Opmus VNK........................................................................................
1.1 Locaon of performing the test.............................................................................
1.2 Posion of microphone.............................................................................................
1.3 Seng up the instrument............................................................................................
2. Performing measurements.............................................................................................
5
5
5
8
10
In order to perform vehicle noise measurements to ISO 5130-2007 and §29 StVZO, there
are strict condions that have to be met when it comes to the setup of your instrument.
This secon will guide you through seng up your Opmus VNK.
1.1 Locaonofperformingthetest
In order to reduce the inuence that surroundings of your environment have on your
vehicle noise measurements, it’s best to choose a locaon that meets the following criteria:
• an open space that consists of a at area made of concrete, asphalt or any other
hard material that has high acouscal reecvity (excluding compressed or other earth
surfaces e.g. soil)
• the edges of the test site (walls, buildings, fences etc) must be at least 3m away from
the exterior of the vehicle being tested. When tesng exhaust noise, the vehicle must
be no less than 1m away from a pavement edge
• any obstacles outside the test site must not be closer than 3m to the microphone
• nobody whose presence inuences the meter readings can be present during the test,
with the excepon of the observer and driver
• tesng should not be done in adverse weather; gusts of wind must not aect the
measurement data
1.2 Posionofmicrophone
The vehicle noise measurement template provided with the Opmus VNK will help
you posion the microphone in the correct place. When measuring exhaust noise, the
microphone should be posioned on the tripod approximately 0.5 meters away from the
exhaust and at a 45˚ angle.
Fit the exhaust into cut-out secon on the
template and extend the antenna to ensure
the microphone is posioned correctly.
The diagrams on the next page provide a
visual representaon of where to posion the
microphone when conducng noise tests on
either a car/van or a motorcycle.

Optimus VNK - Quick Start Guide Taking Vehicle Noise Measurements With The VNK
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Optimus VNK - Quick Start Guide Taking Vehicle Noise Measurements With The VNK
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1.2 Senguptheinstrument
For full operaonal instrucons for the Opmus+ range of sound level meters, please
consult the handbook supplied with the Opmus VNK, or alternavely you can download it
from the Cirrus Research website: www.cirrusresearch.co.uk/library/user-manuals.
Firstly, turn on your Opmus+ by holding the power buon on the side of the instrument.
Once the instrument has loaded, use the le and right arrow keys to navigate to the vehicle
noise screen, as shown below.
In order to capture the three measurements required, you will need to ensure that the
vehicle noise trigger buon (included with the Opmus VNK) is plugged into the sound
level meter, using the 3mm audio jack, which is under the rubber cover at the base of the
instrument.
The microphone is aached to the sound level meter via an extension cable, which can be
aached to the tripod included with the Opmus VNK. Once the microphone is in place,
run the extension cable from the microphone to the cockpit, where you will be able to use
the sound level meter along with the trigger buon.
Microphone and tripod
Preamplier extension
Opmus+ sound level meter
Opmus+ sound level meter
Vehicle noise trigger buon
Image for illustrave purposes only - please refer to previous secon for correct placement of vehicle in tesng site.

Optimus VNK - Quick Start Guide Taking Vehicle Noise Measurements With The VNK
10 11
2 Performingmeasurements
Once your Opmus VNK is set up, you’re ready to begin taking vehicle noise measurements.
The following secon sets out how to use the Opmus VNK to make measurements to ISO
5130-2007 and §29 StVZO standards.
With the car’s engine running at its normal temperature and the Opmus+ sound level
meter turned on, gently press the accelerator to achieve the appropriate number of
revoluons per minute for your vehicle (as per secon 6.4 of ISO 5130-2007). You can use
your car’s rev counter as a guide.
Gradually press the throle to achieve the correct engine speed. Once you’re at the correct
RPM, press and hold the vehicle noise trigger buon to begin the rst reading.
Hold the engine speed for at least one second whilst
connuing to hold the trigger buon. Then, rapidly
release the throle and allow the engine to return to
idling speed, keeping the trigger buon pressed. Once
idling, you should release the trigger buon.
The rst measurement will be recorded in posion
one on the Vehicle Noise screen on your Opmus+.
The measurement will be the LAFMax for the duraon
of when the engine was at the target speed and
throughout the deceleraon period.
For your overall measurement to be compliant with
the internaonal standard, three measurements
must be taken. Your Opmus+ sound level meter will
automacally calculate the LArep from these three
measurements, which will constute the result for
that measurement period.
Once you have captured the rst reading, repeat the
process as described above to capture the second
value. The second measurement will appear in posion
one on the screen of your Opmus+.
Repeat the process a nal me to capture the last
measurement. The third measurement will appear in
posion one on the screen of your Opmus+.
Once three measurements have been taken, the LArep
(average of the three measurements) will automacally
be displayed. This value should be given as the result
of the noise test you’ve just conducted.
If you wish to test another vehicle with the same
instrument or retest the same vehicle, simply press
the trigger buon again when you are ready to take a
measurement. This will overwrite the value in posion
one, as shown below.
Alternavely, you can press ‘Menu’ or the middle buon to open the menu, and then the
‘back’ buon to exit. This will reset the vehicle noise display.

Contact our sales team for more informaon
[e-mail]
Cirrus hold UKAS
calibraonaccreditaon
We can calibrate sound level meters
and acousc calibrators to the latest
Brish standards, as well as octave
band lters.
Having your instruments calibrated
to UKAS standards means that
the data they record is completely
accurate, reliable and traceable.
We also oer standard traceable
calibraon for all types of noise
monitoring equipment and vibraon
meters, from any manufacturer
TRAINING
Needmoresupportin
usingyourinstruments?
Whether it’s product-specic
training, noise at work awareness or
environmental noise training,
Cirrus Research oers a host of
courses to help you become more
condent when it comes noise.
With locaons across the UK and
dates throughout the year, our
courses are perfect for anyone
who’s just starng out in noise
measurement, or for those seasoned
professionals looking to freshen up
their knowledge.
For every hour you spend at one of
our training courses, you’ll earn an
hour of CPD.
ALSO AVAILABLE IN NOISE MONITORING
• Lightweight and robust design
• No controls, dials or screens
• Completely tamperproof
• Monitor individuals’ noise
exposure
• Analyse data with licence-free
NoiseTools soware
The only partner you’ll ever need when it comes to tackling noise
Theworld’srstwirelessdosimeter
• Bluetooth® enabled
• Can be operated through a
smartphone app
• Includes 1:1 octave band lters
• Custom mers can be used for
scheduled measurements
• New discreet design
Simplicityredened
• Noise-acvated warning sign
• Alerts employees as to when PPE
is required
• Various messages available
• Dierent languages available
• Custom noise level trigger can be set
Creangsaferenvironments

www.cirrusresearch.co.uk
[e-mail]
Version 2 - Q2 2020