IMAP

IMAP: Inverse multi-angle Polarimeter with polarization

The IMAP (Inverse Multi-Angular Polarimeter with Polarization) Nephelometer measures polarized scattered light at multiple angles and at multiple wavelengths. As with our other instruments, we use our feedback flow control system to collect data at multiple size bins ranging from PM1 to PM10. Owing to the small size of the sampling chamber and the overall efficiency of the system, this allows us to determine a full particle size distribution within a span of just 5 minutes. 

This advanced instrument collects a huge amount of data thanks to its cutting-edge technology: 3 wavelengths x 7 angles x 2 polarization orientations x 4 size bins. We highly suggest using IMAP for an in-depth understanding of particulate properties. Given its unique combination of aerodynamic and optical sizing, it can be used to effectively connect satellite and ground-based measurements for comprehensive air quality research. To manage all of this detailed information, we use a sophisticated GRASP data retrieval algorithm which allows us to accurately determine: particle mass, size distribution, scattering phase function, polarization phase function, real refractive index of the particles, sphericity factor of the particles.

Data sheet

  • Instrument size: 25cm x 44cm x 30cm
  • Inlet height: 117cm
  • Flow rate: 1.5 to 12 litters per minute
  • Data: Saved to an SD card.  Real time data access via USB, RS485, RS23
  • Access: Remote access via wifi or cell network through AirPhoton Com100 module (add-on)
  • Calibration: Operational daily provided by CR100 Clean Air Reference
  • Gas calibration: CO2 and clean air every 3-6 months (depending on operating conditions)
  • Power: Mains AC power. 120- or 240-Volt systems (50 and 60Hz). 60 W maximum load. A 5-Amp circuit breaker is included that also acts as the on-off switch.
  • Minimal scattering coefficient: < 1E-7  Mm-1   (For any particle size)
  • Maximum scattering coefficient: it can be adjusted by reducing integration time.  Typically between 2E –3 Mm -1 to 2E-2 Mm -1 are achievable by tuning the settings to your application.
  • Angular ranges measured: 8 View angles centered at 5 °, 10.5 °,31.8°, 63.5°, 95.3°, 116.5°, 148.2°, 169.4°
  • Field of view: Instantaneous <7.5°
  • Wavelengths: (3) 470nm, 529 nm and 621 nm
  • Polarization orientations: 2 Parallel and perpendicular to the scattering plane.
  • Size measurements: 4 Size bins ranging from PM1 to PM10.

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

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

Can the instrument be connected to sampling manifolds rather than direct air intake (as long as pressure upfront the cyclone does not significantly deviate from ambient pressure)?

Yes the instrument can be connected to manifolds. The instrument can also operate without the cyclone if that is a concern for the user.

Can the flow rate be chosen freely, or is it fixed for a given upper diameter cut-off in the cyclone mounted in the inlet?

The active flow rate of the instrument is limited by its internal blower (fan). If the user wants a flow rate outside the range of our blower, the user can always use an external pump or blower.

Can the instrument also run at low ambient pressure (with potentially shifted flow rate or cut-off range)?

Yes, the instrument can run at lower pressure. Pressure correction may be needed for the aerodynamic behavior of the cyclone or for Rayleigh scattering considerations.