Accession Number : ADA019630

Title :   The Continuous Aluminum-Foil Hydrometeor Sampler; Design, Operation, Data Analysis Procedures, and Operating Instructions.

Descriptive Note : Instrumentation papers,


Personal Author(s) : Church,James F. ; Pocs,Konstantins K. ; Spatola,Alfred A.

Report Date : 11 JUL 1975

Pagination or Media Count : 70

Abstract : The continuous aluminum-foil hydrometeor sampler is an airborne meteorological instrument that uses a continuous ribbon of aluminum-foil which moves at a constant speed past a 14.51 sq cm sampling area aperture exposing the foil to the ambient air-flow inflight. The aluminum-foil is backed by a rotating drum for exposing the foil immediately behind the aperture as well as for metering the amount of foil exposed in relation to the drum's rotational speed. This drum is finely grooved to enhance the imprint of the impacting hydrometeors. Both liquid drops = or > 100 micrometers and solid particles = or > 50 micrometers can be identified, measured, and counted. The frozen particles, depending upon orientation, impact on the foil leaving an almost exact replica. However, the imprint size of liquid drops can be up to 30 percent greater when sampled on a C-130 aircraft, depending on the true air speed of the sampling. Knowing the true aircraft speed, the foil advance speed, aperture width, and the ratio of imprint to true size, the hydrometeor size distribution and mass concentration can be determined along the aircraft's sampling path.

Descriptors :   *Hydrometeors, *Meteorological instruments, *Samplers, Ice, Raindrops, Snow, Cloud physics, Detectors, Aluminum foil, Airborne, Counting methods, Sizes(Dimensions), Impact, Moisture content

Subject Categories : Meteorology
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE