An optical sensor for the measurement of microphysical and optical properties of aerosol and cloud particles

Period of Performance: 07/01/1997 - 06/30/1999


Phase 2 SBIR

Recipient Firm

Droplet Measurement Technologies, Inc.
2545 Central Avenue
Boulder, CO 80301
Principal Investigator

Research Topics


Droplet Measurement Technologies proposes to build a compact, lightweight optical sensor that measures the size and concentration of aerosol and cloud particles between .3 um and 3.2 mm, the refractive index and phase of particles between .3 and 50 um, and the liquid water content of cloud droplets between 2 and 50 um. The sensor combine three sensors into a single package. The serosol/cloud sensor measures scattered light in the forward and backward direction to derive size and refractive index, the precipitation sensor measures light occulation to capture a particle's image, and the liquid water sensor uses the DMT hot-wire technology to measure the power required to evaporate water droplets. This three-way sensor has been successfully built as a laboratory system and tested with water droplets and aerosols. Phase II will see its integration into an airborne package that fits into commercially available aircraft canisters. Characterization of airborne particles is of great interest to both scientific and commercial agencies. The new instrument will provide new capabilities in pollution monitoring, agricultural spray diagnostics, aircraft icing studies and monitoring, global climate change studies, and cloud microphysics research. The proposed instrument bridges a measurement range that has costly to cover in term of dollars and weight. Combining the measurement of multiple parameters in a single package provides great cost and weight savings and will allow more investigators and companies access to an important measurement capability at a much lower cost than presently available. The built-in analysis capability of the instrument makes its usage very simple and data recording trivial. Theses are all features that will appeal to users that want a turnkey for their application.