Environmental Noise Measurement Kits

Make accurate, compliant noise measurements in any environment

Make effective, accurate noise measurements with your Optimus+ sound level meter

The environmental noise measurement kits from Cirrus Research provide a robust, reliable solution for short, medium and long-term measurements in any environment.

Protecting your sound level meter and microphone capsule from adverse weather and environmental conditions, the kits provide power, security and connectivity for your Optimus+ sound level meter under any conditions giving you accurate, informative and actionable data that allows you to stay compliant and informed, wherever you are.

When combined with the power of the industry-leading Optimus+ sound level meters, the new outdoor kits provide a powerful and cost-effective way to stay in control of noise levels in any environment.


  • Unattended outdoor noise measurements
  • Noise monitoring in remote areas
  • Construction site noise monitoring
  • Environmental impact assessments
  • Wind Farm noise monitoring

Key features of all versions

  • Take noise measurements outdoors in all weather conditions
  • Provides protection for the sound level meter & measurement microphone from adverse conditions
  • Easy to transport & install with a secure, lockable case
  • Flexible power options using internal batteries & external power

Additional features provided by the CK:685B version

  • Get real-time notifications to the Mycirrus Notifications App to help you manage and control noise levels
  • Simple setup & configuration using a standard SIM card & a data connection
  • Download measurements remotely to the NoiseTools software
  • GPS location data stored with each measurement
  • Modem with worldwide certification

Features provided by the Optimus+ Green sound level meters

  • Options of Class 1 or Class 2 instruments
  • Acoustic Fingerprint triggers with markers & audio recordings
  • Level, Rate-of-change, Frequency or Tonal noise-based triggers*
  • 1:1 & 1:3 Octave Bands*
  • Tonal noise detection*
  • Data logging of all parameters simultaneously
  • 4GB standard memory with 32GB option
  • Triggered audio recording with pre & post triggers

*Some features are dependent upon the type of Optimus+ sound level meter used.

Environmental Noise Measurement Kit

Real-time notifications with MyCirrus

What is MyCirrus?

MyCirrus is a web-based platform that allows Cirrus Research noise measurement instruments to communicate with either the NoiseTools desktop software, the MyCirrus App or a web page on a hand-held device such as a smartphone or tablet.

MyCirrus works with the CK:685 Environmental Noise Measurement Kits and the Optimus+ Green sound level meters.

Stay on top of your noise measurement with real-time notifications

When used with an Optimus+ Green sound level meter, MyCirrus allows real-time notifications to be sent directly to the Notifications App, removing the need for costly SMS subscriptions.

By using the power of the level, rate of change and frequency-based triggers within the Optimus Green instruments, notifications can be sent when specific noise conditions occur.

Trigger rules can be as simple or complex as needed. For example, triggers can be set to activate when:

  • The measured LAFmax exceeds 65dB(A) for more than 5 seconds or
  • When the accumulated noise energy has reached 75% of an hourly limit or
  • When the 125Hz 1:3 Octave Band has exceeded 60dB AND the 63Hz 1:1 Octave Band has exceeded 70dB

The power and sophistication provided by the triggers within the Optimus Green Sound Level Meters allows almost any noise condition to be monitoring and notifications sent when those conditions are breached or exceeded.

MyCirrus allows these trigger notifications to be sent quickly and easily to the Notification App (iOS and Android), giving you the power to stay informed and in control of your noise measurements.

What makes the Cirrus Research Environmental Noise Measurement Kits different?

Our Environmental Noise Measurement Kits have been specifically designed to be used in harsh environments, such as on construction sites or where there is a risk of damage to the sound level meter or microphone.

The solid, robust and rugged case protects your sound level meter from damage and tampering whilst the purpose designed outdoor microphone provides protection for the microphone capsule. We've used professional-grade connectors (not just slots in the case which can allow moisture to get into the case) as well as ensuring that you can transport all of the kit inside a single case, making it easy for you to install, collect and gather data.

When you buy a Cirrus Environmental Noise Measurement Kit, you benefit from over 40 years experience in the design, manufacture and support of noise measurement equipment that has been designed to be used outdoors and over long periods of time.

For peace of mind, your investment is also backed by our industry-leading 15 year warranty.

It's not just a sound level meter inside a box, it's a Cirrus Environmental Noise Measurement Kit.

Applications for the Environmental Noise Measurement Kits

Unattended environmental noise measurements

The environmental noise measurement kits provide weather protection for the sound level meter and the microphone, allowing for noise measurements over long periods where the equipment is unattended.

This allows effective, accurate noise measurements to be made where it’s not possible to have staff on-site with the equipment at all times.

  • Robust and secure case protects the Optimus Sound Level Meter
  • Carry out noise monitoring even when you can't be on site
  • Calibrated, accurate measurement data lets you make more effective decisions
  • Download information into NoiseTools directly or remotely, giving you access to your data when you need it

Construction site noise monitoring

For construction sites, receiving real-time alerts when pre-set noise limits have been exceeded, or are close to being exceeded, can be an effective noise control process.

As this information can be provided in real-time (either to staff on-site or to a remote office) it can enable site managers to investigate the source of the noise and to take quick, effective actions to remedy the issue.

The MyCirrus Notification App provides real-time notifications and alerts, allowing for effective control of construction site noise levels.

  • Configure triggers in the Optimus Green to match site noise limits
  • Stay informed as noise levels approach those limits by utilising triggers and notifications
  • Receive real-time alerts through MyCirrus direct to the Notifications App on your phone or tablet

Noise monitoring in remote locations

In many environmental noise monitoring applications, having the ability to download measurements remotely, when the equipment is located far away, can be vital.

The CK:685B variants include the remote communication option and allow for measurement data to be downloaded, the instrument configured and real-time alerts to be sent to the MyCirrus Notification App.

  • Deploy noise measurement stations to any location or environment and be confident that you'll gather accurate, informative and actionable data
  • Where measurements are to be made over a long period, use external power to provide weeks or months of noise logging capability
  • Download summary measurement data remotely to the NoiseTools software via the modem and MyCirrus allowing you to stay informed about the status of the equipment and on-going measurements

Environmental Impact Assessments

For environmental impact assessments such as a BS4142 application, measurements when noise sources are not operating (over a weekend for example) can be critical in determining if there is significant impact when the site is in operation.

By using an environmental noise measurement kit, data can be gathered over extended periods when noise sources are and are not operating, allowing more robust assessments to be made.

  • Measure noise levels over long periods to cover both on and off conditions for the noise sources under investigation without having to be with the equipment
  • Gather accurate, informative noise data regardless of the weather conditions or the environment that the equipment needs to be left in
  • Configure triggers in the Optimus Green Sound Level Meter to activate when known noise sources are active, whether you're on site or not.
  • Receive real-time notifications when triggers are activated and store high-resolution audio recordings, allowing you to determine the source and type of noise being measured
  • Quickly identify and highlight noise sources in the NoiseTools software to determine if penalties should be applied, creating reports and exporting data for analysis in other software packages

Wind farm noise monitoring

Logging data over long periods before, during and after the construction of a wind farm can often be the only way to effectively judge the impact of operations and the environmental noise measurement kits can assist in this task.

The advanced triggers in the Optimus sound level meters can provide real-time alerts when overall levels or specific frequencies are exceeded as well as when tonal noise is detected.

  • Use the power of the Optimus Green Sound Level Meters to log detailed noise data over long periods of time
  • Make measurements over long periods by adding external power to the kits from a battery, mains or solar power
  • Use the advanced triggers in the Optimus Green to detect tonal or frequency-based noise sources
  • Send real-time alerts & notifications to the MyCirrus App when triggers are activated
  • Download measurement data without having to visit the equipment using the modem, MyCirrus and the NoiseTools software

Versions of the Environmental Noise Measurement Kits

CK:675B Environmental Noise Measurement Kit

The CK:675B version of the Environmental Noise Measurement Kit is supplied complete with all of the parts needed to effective noise measurements outdoors, in any environment.

Simply add an Optimus Sound Level Meter and Acoustic Calibrator and you have a cost effective, robust system that can help you make accurate, actionable noise measurements anywhere, at any time.

What's in the kit?

  • Secure, lockable weatherproof Case
  • MK:172 Outdoor Microphone with 10m cable & UA:253 windshield
  • 2 x CB:673 12V Batteries & Battery Charger
  • User Manual
  • Certificate of Conformance
Please note: microphone tripods are optional extras and are not included with the kit.

CK:685B Environmental Noise Measurement Kit

For remote access to the instrument, the CK:685 kits include a GPS receiver and modem which, when used with MyCirrus, allow for measurements to be downloaded to the NoiseTools software, the instrument configured and alerts sent when pre-set noise conditions are met.

Alerts can be sent directly to the MyCirrus Notification App, via email or SMS1 text, all of which can be easily configured by logging into the Mycirrus.

Features over the CK:675B Kit

  • Modem to download measurement remotely & send notifications to MyCirrus
  • GPS Receiver stores location data alongside the noise measurements
  • Automatic synchronisation of the instrument to the GPS signal

What's in the kit?

  • Secure, lockable weatherproof Case
  • MK:172 Outdoor Microphone with 10m cable & UA:253 windshield
  • Worldwide certified modem for remote data download & real-time notifications
  • GPS Receiver for location data & time/date synchronisation
  • 2 x CB:673 12V Batteries & Battery Charger
  • User Manual
  • Certificate of Conformance
Please note: microphone tripods are optional extras and are not included with the kit.

Ordering Information

The environmental measurement kits can be ordered with or without the Modem/GPS option or with and without one internal battery pack/charger using the following product codes.

Code Description Included Modem & GPS
CK:675B Environmental Noise Measurement Kit No
CK:685B Environmental Noise Measurement Kit Yes

Please note that the kits do not contain a sound level meter or acoustic calibrator.


Acoustic Measurements Determined by Optimus Green Sound Level Meter
Microphone Capsule From Optimus Sound Level Meter
The microphone capsule provided with the sound level meter should be used with the MK:172 outdoor microphone to maintain the calibrated measurement chain.
Connectors Microphone input from MK:172 Outdoor Microphone
External Power
External power 12-18v DC
Weight & dimensions CK:675B
14.1/31 lbs including 2 x CB:673 batteries, charger & MK:172 Outdoor Microphone

14.5 kg/32 lbs including modem, 2 x CB:673 batteries, charger & MK:172 Outdoor Microphone

CB:673 Battery
4.4 kg/9.7 lbs

MK:172 Microphone
335mm with 90mm UA:253 coated windshield & birdspike
Includes 10m cable with connector

For detailed specifications for the Optimus Sound Level Meters, please refer to the appropriate product data sheet.

Dimensions & weights do not include the optional CT:9 Tripod.

Modem Approvals (CK:685B)

The CK:685B version of the environmental noise measurement kit include a modem for remote data connection to the MyCirrus. This modem provides multi-region approvals and certifications and can be used with a standard SIM card.

  • Modem Type - Multitech MultiConnect MTC-H5-B0-1
  • Compliance - FCC Class B (US), IC (Canada), R&TTE (EU Economic Area, A-Tick (Australia/NZ), and IFT (Mexico)
  • Safety - UL 60950-1 (US), cUL 60950-1 (Canada), IEC60950-1 (EU Economic Area), AS/NZS 60950-1 (Australia/NZ)
  • Network Support - PTCRB, GCF approved module, AT&T, T-Mobile, Rogers, Bell, EU carriers, Pending: Telus, Telstra
  • SIM Card Type - Mini SIM; 1.8v & 3V

Instrument Compatibility

The kits have been designed to be used with the Optimus Green Sound Level Meters and can be used with instruments with firmware version v3.0 shipped from 1st February 2018.

Instruments with firmware version 2.9 or earlier will need to be updated to version 3.0. Please contact Cirrus Research for details of update options.

Product Information

Product Datasheets

User Manuals

Contact Our Environmental Noise Experts

Let us help you find the best environmental noise measurement solution to meet your needs.

Cirrus Research UK

  • 0845 230 2434 (UK)
  • +44 1723 891655 (INT)
  • sales@cirrusresearch.co.uk
  • Cirrus Research plc
    Acoustic House
    Bridlington Road
    North Yorkshire
    YO14 0PH
    United Kingdom

Cirrus Research plc Deutschland

  • +49 69 95 93 2047
  • www.cirrusresearch.de
  • vertrieb@cirrusresearch.de
  • Arabella Center
    Lyoner Strasse 44-48
    D-60528 Frankfurt

Cirrus Research S.L.

  • +34 933 622 891
  • www.cirrusresearch.es
  • infos@cirrusresearch.es
  • Av. Diagonal 468, 6°
    08006 Barcelona

Cirrus Research France SAS

  • 0 805 111 570 (Numéro Vert)
  • www.cirrusresearch.fr
  • infos@cirrusresearch.fr
  • 679 avenue de la République
    59800 Lille

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