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Accurate, compliant noise measurements in any location

The latest environmental noise measurement kits from Cirrus 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

Get more from your sound level meter

When you add an environmental noise monitoring kit to your Cirrus Optimus sound level meter, you expand the range of applications and environments where you can make measurements. 

24/7 Noise Measurements

Use the internal batteries or external power options to log effective, accurate noise data over long periods, giving you the information you need to make informed decisions and meet environmental noise standards worldwide.

Real-time alerts & notifications

Use the power of the Acoustic Fingerprint triggers in the Optimus Green Sound Level Meters and the Optimus Cloud to send real-time alerts and notifications when pre-set noise conditions are met.

Deploy the Optimus Cloud app to any device to stay in control of noise levels and ensure you stay compliant with limits and regulations.

Download data, anywhere, anytime

The CK:685 kit allows measurements to be downloaded to the NoiseTools software via its internal modem as well as giving the flexibility to configure the sound level meter to meet changing demands.

Protect your investment

The robust case protects your sound level meter, acoustic calibrator and outdoor microphone from damage, ensuring your are ready to go at a moments notice with accurate, compliant noise measurement equipment.

Key Features

  • 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
  • 2 x CB:673 Batteries included as standard

Additional features of the CK:685B

  • Live data connection to the Optimus Cloud for realtime alerts & notifications
  • Notifications direct to the Optimus Cloud app (iOS & Android) or via SMS, Email or Twitter
  • Download measurements remotely to the NoiseTools software
  • GPS location data stored with each measurement

Additional features provided by the Optimus Green Sound Level Meters

  • Options of Class 1 or Class 2 instruments
  • Acoustic Fingerprint triggers with markers & audio recordings
  • Notifications to the Optimus Cloud when triggers are activated
  • 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

* Dependent upon instrument type