Online Instrumentation

TROPOS uses a wide variety of instruments to measure both atmospheric gas- and particle-phase compounds. Some of the instruments we use routinely are briefly described here.


Fourier transform infrared spectroscopy (FT-IR)
An FT-IR spectrometer is used in laboratory trace gas and VOC oxidation experiments in which the instrument provides information about the presence of multiple gas-phase compounds with immediate results.

Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)
A PTR-MS provides real-time analysis of VOCs in both laboratory and field experimental setups.

Chemical Ionization Atmospheric Pressure interface Time-of-Flight Mass Spectrometry (CI-APi-TOFMS)
Similar to PTR-MS, the instrument is used in both laboratory and field experimental setups. It accepts a wider variety of chemical ionization reagents than the PTR-MS. The choice of the ionization reagent determines the class of compound to be detected.

Monitor for Aerosols & Gasses in Ambient Air (MARGA)
Mostly used for field measurement studies, this instrument consists of a wet rotating denuder, steam jet aerosol collector and ion chromatography, and it is used to determine inorganic gas- and particle compounds in ambient air.

Particle-Into-Liquid-Sampler (PILS)
This instrument is designed to collect particles in an airstream by condensing water vapour on them, and subsequently transferring them into an aqueous solution. The solution can be analysed for inorganic ions, small organic acids and WSOC.

Aerosol Mass Spectrometer (HR-ToF-AMS)

Used either for field and laboratory measurements, the High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) provides size resolved chemical composition of the near PM1 aerosol.

Aerosol Chemical Speciation Monitor (ACSM)

Directly derived from the AMS, the ACSM is used for monitoring measurements mostly at the research site of Melpitz and it provides a 30 min time resolution near PM1 aerosol chemical composition.