Two instruments have been installed so far at the station:
From December 2011 to February 2024: AE31-HS aethalometer
From September 2023 onwards: AE33 aethalometer
The Aethalometers measure aerosol light absorption properties in 7 different wavelengths: 370 nm (UV), 470 nm (blue), 520 nm (green), 590 nm (yellow), 660 (red), 880 nm (IR1m “standard Black Carbon”) and 950 nm (IR2). They measure the rate of change of optical transmission through a spot on a filter on which aerosol is being continuously collected, and converted this to a calculation of the concentration of optically-absorbing material in the sampled air stream. At Chacaltaya data, one data per wavelength is stored every five-minutes.