Aircraft-based Counterflow Virtual Impactor Inlet System Model 1204


A virtual impactor inlet designed to probe the properties of cloud condensation nuclei inside real clouds from aircraft and ground-based sites.

The Brechtel Model 1204 CVI is a virtual impactor inlet ideal for probing the detailed properties of actual CCN inside real clouds. The CVI was developed for aircraft deployment so researchers could explore aerosol-cloud interactions across a broad spectrum of cloud types and under different air mass source region conditions. Extensively wind-tunnel tested to characterize size-dependent transmission efficiencies, the CVI inlet has been successfully deployed in multiple field campaigns where excellent agreement was found between wing-mounted cloud probes and instruments sampling the CCN from the CVI. Add the ground-based operation kit to your CVI and the modular design can be operated at mountain stations and other sites with clouds near the ground.

Learn About Product

All Features
• Includes CVI probe, control chassis, vacuum pump and dry air compressor
• Controllable droplet cut size (7 to 15 microns)
• Easy to remove tip for cleaning and replacement
• 15 lpm of instrument sample flow
• Laminar flow element measures sample flow and automatically adjusts to changing instrument flows
• Counter flow rate adjustable between 1 and 10 lpm to vary droplet cut size in real-time
• Heated and Dried Add Flow to evaporate cloud droplets
• Anti-icing system
• Optional kit for Ground-based operation
  • Fully automated, hands-off operation
  • Wind tunnel tested, field validated and peer-reviewed
  • Designed for long-term, unattended deployment
  • Custom mounting solutions available
  • Easy to vary droplet cut size in real-time
  • Easy to use control software
Technical Specs

Copyright ©2024 All specifications are subject to change without notice. BMI assumes no responsibility for inaccuracies in this document or for any obligation to update information in this document. BMI reserves the right to change, modify, transfer or otherwise revise this publication without prior notice.

*Some products may be shown with optional accessories, which are sold separately. Items shown may not be to scale.

Applications and Solutions
  • Aerosol-Cloud Interaction Studies
  • Aircraft-based CCN measurements
  • Weather modification studies
  • Cloud condensation nucleus studies
  • Cloud microphysics & radiation studies
  • Pollution impacts on clouds
  • Visibility impacts of fogs
  • CCN & precipitation feedbacks
  • Global climate model CCN datasets

The CVI built-in firmware allows you to operate and configure the system from just the electronics chassis, no external computer is required. The front panel display of the chassis provides real-time displays of current parameter values, including Add Flow, Total Sample Flow, Counter Flow, and True Airspeed. You can quickly change the Add Flow to adjust the droplet cut size to suit your sampling needs. Operating pressure and various temperatures are monitored to automatically maintain proper flow and anti-icing control.

The same on-board firmware also allows easy access to default system settings so you can customize the performance to your needs. Data can be saved locally to an SD Card accessible through the front of the chassis and/or data may be exported in real-time to an external computer for display and storage. Key control parameters like True Air Speed and Ambient Temperature can be imported via serial communications if your sampling setup already has these sensors deployed. Finally, checking and changing calibrations is a snap with the configuration and calibration tools – all calibration coefficients are accessible for easy update after new calibrations are performed. It is the customer’s responsibility to supply the platform airspeed to the CVI firmware via RS-232 communication from the platform data system or by deploying a user-supplied pitot-static tube that may be connected to the calibrated, internal differential pressure sensor in the CVI control chassis.

What's Included
• External probe assembly with de-icing system and standard mounting plate
• Rack-mount electronics chassis with firmware
• Self-regenerating compressed dry air supply system
• Sample flow vacuum pump
• Interconnect cables and tubing
• Operator’s Manual

Note: It is the customer’s responsibility to physically mount the CVI inlet to their aircraft or other platform and to supply valid true air speed data to the CVI inlet during operation.

The following optional accessories are available:

Find Your Team Of Experts & Share Your Inspirations