European Facility For Airborne Research

European Facility For Airborne Research May 29, 2022, 10:15

Instrument: M55 CVI package

Name M55 CVI package
Acronym CVI-M55
Manufacturer MISU Stockholm, Uni. Mainz, IEQ-CNR, IFA-CNR, IROE-CNR, Uni.Berlin
Operated by Geophysica-GEIE
Operated onboard

Instrument type

Name Counter-flow Virtual Impactor (CVI)
Acronym Counter-flow Virtual Impactor

Principle of operation

Measured parameter
Operating principle

Sample arm has heated dry air blowing OUT of it into airstream. Location of flow stagnation plane within intake determines minimum aerodynamic size of particles that can enter. Liquid or ice cloud particles enter intake, where water evaporates leaving cloud drop residual and water vapour.

Measurement(s) Aerosol

Dimension and weight

External dimension
Weight 337.0


Operating mode In situ






three parts:COPAS (two channel condensation nuclei counter) Lyman-a water vapour instrument TDL to measure nitric acid HNO3 This is a particular inlet, which permits the passage only of particles having a kinetic energy larger a given value, thus having a diameter larger than a critical one, generating a dynamical blocking through a couterflow of known and controlled air. The particles that are able to pass this dynamic barrier are heated, because of the barrier, and evaporate.

<u>Alternative techniques :</u> determine the nunber concentration and condensed water content of tropical cirrus cloud elements larger then approximately 2mm radius; and determine the concentration of nitric acid (HNO3) associated with the condensed phase material in tropical cirrus clouds.

Operational restriction

Operational requirements

Certification approvals

Additional information

MISU, Stockholm University of Mainz, GermanyIEQ-CNR, IFA-CNR, IROE-CNR, Italy Free University of Berlin, Germany

Access, host and processing


Could also fit on any aircraft having the following characteristics

General description

Title Author Type Related
No documents.
Back to top
Copyright © 2022 EUFAR All rights reserved.