The aerosol and trace gas group uses a variety of instruments and methods. These include:

Mass Spectrometers:

- Nitrate Chemical Ionization-Atmospheric Pressure interface-Time Of Flight mass spectrometer (nitrate CI-APi-TOF) using a long time of flight chamber (LTOF); the instrument is mainly used for the measurement of gas phase sulfuric acid and highly oxygenated organic molecules (HOMs) during laboratory and field studies.

- Water cluster Chemical Ionization-Atmospheric Pressure interface-Time Of Flight mass spectrometer (water cluster CI-APi-TOF) mainly for ammonia, amine and diamine measurements during laboratory and field studies; the instrument is currently modified to a nitrate CI-APi-TOF for  aircraft measurements.

- Proton Transfer Reaction-Mass Spectrometer (PTR-MS) using a quadrupole MS for measurement of volatile organic compounds (VOCs)

The group has also developed / uses several instruments, techniques and numeric models:

- Corona ion source generating nitrate reagent ions mainly for ultrasensitive (parts per quadrillion, ppqv, range) sulfuric acid, iodic acid and highly oxygenated organic compound (HOM) measurements.

- Cross-flow corona ion source generating protonated water clusters mainly for ammonia, amine, diamine and iodine species measurement at parts per quadrillion, ppqv, or parts per trillion, pptv, levels.

- Sulfuric acid source for accurate calibration of a nitrate CI-APi-TOF.

- Thermal Desorption-Differential Mobility Analyzer (TD-DMA) combined with a nitrate CI-APi-TOF, which can measure the chemical composition of nano aerosol particles (ca. 5 to 30 nm in diameter) at atmospherically relevant concentrations.

- Condensation particle counter VIPER (VIsual expansion-type Particle counter) using water as condensing fluid for measurement of nano particle concentrations (above ca. 3 nm).

- A flow tube has been set-up for laboratory measurements relating to new particle formation and aerosol growth.

- Sulfuric Acid Water NUCleation (SAWNUC) numeric process model for calculation of new particle formation rates from sulfuric acid and water (also Ehrhart et al., 2016; Münch and Curtius, 2017).

- Sulfuric acid Ammonia NucleaTIon And GrOwth (SANTIAGO) numeric process model for calculation of new particle formation and growth rates from sulfuric acid, water and ammonia.

Furthermore, a set of particle counting and sizing instruments as well as trace gas monitors are used to conduct field measurements and to characterize other instruments.