From symposium on environmentl surveillance around nuclear installation; Warsaw, Poland (5 Nov 1973). A new concept in the sizing of radioactive or nonradioactive airborne Particulate matter has been assembled into a mobile field unit and is being applied to present environmental and health physics particle size information needs. The glow-discharge perturbat ion method economically generates particle size data which can be directly accumulated and spectrometrically analyzed by a multichannel analyzer. The basics of the glow- discharge technique are touched upon and compared to other instrumentation presently available in this province of the environmental sciences. The physical description, operational characteristics and current uses of the apparatus are detailed, along with importnt design and operational parameters. Particle size distribution data and analysis techniques illustrating the utility of this system are presented. (auth).