A Miniature Optical Particle Counter for In Situ Aircraft Aerosol Research

Abstract

Modification of a commercial Met One 237A optical sensor to accept custom electronics consisting of a single logarithmic amplifier providing 256 size bins over the 0.3?14-?m diameter range is described. Configuration of the optical particle spectrometer for airborne aerosol measurements is found to be effective for both miniature remote control aircraft and large research aircraft (NASA P-3B). The instrument is rugged, of low cost, uses low power, and is easily integrated into various platforms. The high size resolution and the 1.6 l min?1 sample rate provide excellent count statistics and high sensitivity for ambient out-of-cloud aircraft measurements and for other diverse applications. It can be readily configured for isokinetic or subisokinetic aircraft sampling. Initial comparison with other optical particle counters over the Sea of Japan reveals it to be an effective instrument for in situ aircraft measurements.