A battery-portable respirable aerosol sensor has been experimentally evaluated. Calibration procedures are described. For instruments calibrated with welding smoke, test results show agreement within ± 15% of parallel filter samples for 10 laboratory and industrial aerosols including welding and tobacco smoke, oil mist, cotton and asbestos mill dusts, powdered metal and walnut shell dusts, and atmospheric urban aerosol in the 0.05–5.5 mg/m3 range. Results show that an average of several piezobalance measurements can accurately simulate a time-integrated filter sample in many industrial environments.