Mini-IMAP

A new instrument for particulate characterization with single-wavelength polar nephelometry

The mini-IMAP is a moderate-cost, single-wavelength polar nephelometer designed for detailed characterization of airborne particulates. When used in combination with the GRASP data inversion algorithm, it enables the retrieval of particle size distribution, PM2.5 mass concentration, and the phase function of the particles.  The system integrates a feedback flow control mechanism with a cyclone inlet to achieve aerodynamic separation of particles. This setup allows for the collection of data across multiple size bins, ranging from PM1 to PM10. The compact sampling chamber and the overall efficiency of the system enable fast response times and short measurement cycles, making it suitable for real-time or near-real-time analysis.

By combining aerodynamic and optical sizing, the mini-IMAP provides valuable information on how satellite-based optical aerosol observations correspond to the aerodynamic particle sizes that influence respiratory system deposition. The instrument measures scattering at ten angles between 10° and 160°. The standard operating wavelength is 515 nm, with optional configurations available at 405 nm (blue) and 638 nm (red).

  • Instrument size: 11.8″ × 9.8″ × 14.2″ / 30cm x 25cm x 36cm
  • Inlet height: 40.2″ / 102cm
  • Flow rate: 1.5 to 11 LPM (BGI Inlet); 2.0 to 15.3 LPM (Alaric Inlet)
  • Data: Saved to internal storage. Real-time access via Ethernet / RS232 / RS485 / WiFi (add-on)
  • Gas calibration: CO2 and clean air every 3–6 months
  • Power: AC power. 120 or 240-Volt systems (50 and 60Hz). Expected Operation at 100W; Estimated Peak at 150W.
  • Time resolution: 1 min averaging (recommended); 15 sec averaging (minimum).
  • Angular ranges measured: 10 View angles 10°, 19.5°, 36°, 53°, 71.5°, 90°, 108.5°, 126.5°, 144°, 160.5° (degrees)
  • Instantaneous field of view < 7.5°
  • Wavelengths: 515 nm standard 405 or 638 nm options
  • Size measurements: Independent optical and aerodynamic size measurements
    • Aerodynamic: 4 Size bins selected up to PM10 (possible every 5min)

The IMAP can provide complete size distribution measurements every 5 minutes, particle mass, full phase function, real refractive index of the particles and sphericity factor.

We suggest mini-IMAP for in-depth understanding of particulate properties. Given its unique combination of aerodynamic and optical sizing it can be used to connect satellite and ground-based measurements for air quality research.

● Mini-IMAP flyer – Mini-IMAP datasheet.pdf