LOAC (Light Optical Aerosol Counter)
Instrument and pump: 300 g 
Electric consumption: ~3 W 
No lenses => no risk of misalignment 
Concentrations for 19 size classes 
between 0.2 and 100 ┬Ám 

Automatic check every 10 minutes and electronic recalibration if necessary (ex. strong changes in ambient temperature) 
Total weight (gondola, batteries and LOAC): 
1 kg for use with meteorological balloons