University of Hertfordshire

View graph of relations


This 18-month proof-of-concept Proposal was aimed at producing a prototype, low-cost and light-weight optical scattering sensor - the Atmospheric Particle Classifier. The APC would count, size and classify atmospheric particles in the size range ~1µm to 100µm, in-situ and at rates up to ~3,000 particles/s. It would differentiate droplets, solid aerosol, and ice crystals on the basis of shape, and classify the latter into broad ice habit classes (eg: columns, platelets, rosettes, etc.). In addition, the practicality of the sensor determining the extinction coefficient of each individual measured particle would be investigated.
The principles of operation of the APC would build on those successfully deployed in the SID (Small Ice Detector) aircraft probes developed by the University of Hertfordshire and used on the FAAM, HIAPER and other atmospheric research aircraft as well as in laboratory-based cloud ice chambers in the USA and Europe. However, through radically different implementation of these principles, the APC would have a target weight <1kg and a target one-off build-cost of <£3k.
The sensor would be small enough to be borne by tethered-balloon or UAV, or to be carried on Rosemount or non-research commercial aircraft mounting points. Alternatively, it could form part of a combination probe carried in a single PMS canister, potentially replacing particle spectrometers such as FSSP and SID probes and freeing valuable PMS berths). It could be deployed on smaller research aircraft (eg: many in the EUFAR fleet) that either don't have PMS mountings or have only one or two. Beyond this, the sensor could also find application as a hand-held device for ground-level aerosol monitoring and characterisation, in activities such as workplace monitoring, occupational hygiene, source apportionment, pollution dynamics, solid/liquid aerosol phase discrimination, etc. The research, construction, and initial testing of the prototype sensor would be carried out at the University of Hertfordshire, with full performance characterisation, validation and calibration being carried out by the University of Manchester using inter alia their 10m-fall Cloud Ice Chamber. The finished APC would be retained by UoM for incorporation within the UFAM instrument pool, open to all of the NERC science community.


  • Particle classification technology

    Impact: Quality of life Impacts

  • Commercial licence - Alphasense Ltd.

    Impact: Economic Impacts, Quality of life Impacts

Research outputs

ID: 8990867