Integrating Nephelometers
 
Two different instruments were installed at the station during non overlapping periods:

• Ecotech Aurora 3000 Integrating Nephelometer from 2011 to 2021 (without external valve)
• Ecotech Aurora 4000 Polar Integrating Nephelometer from 2022 onwards
  • Working without external valve in 2022
  • Working with external valve since 2023 (in compliance with ACTRIS network recommendations)

These instruments measure both aerosol total scattering (σsp, between 10º and 170º) and back-scattering coefficients (σb, between 90º and 170º) at three wavelengths: 450 nm (blue), 525 nm (green) and 635 nm (red).  The polar nephelometer also offers integrated scattering of up to 17 different angular sectors from 10˚ to 90˚.

Forward scatter can be calculated from subtracting backscatter from total scatter. The measured values are adjusted automatically and in real-time by on-board temperature and pressure sensors. The dimension of σsp are inverse length (inverse megameters Mm-1) and the instrument measurement range goes from <0.25 to 2000 Mm-1.  Raw data is stored every minute.

Contact person: Isabel Moreno

Aurora 3000 Multi Wavelength Nephelometer

Polar integratin nephelometer Ecotech Aurora 4000 with external valve control

---