Direct-read, continuous nephalometer (light-scattering detection) monitors aerosols with particulates 1 to 10µm diameter from 0.001 to 400 mg/m³. True volumetric control ensures proper gravimetric size-selective analysis using two very sharp cut cyclones. Compensated for pressure differentiation and RH. Available with optional filter holder for subsequent after-sample analysis and verification. Internal HEPA filter for on-board zeroing. The I65 weather-rated enclosure includes omni-directional inlet and handle for easy relocation. Operates off battery or DC power.