We are proud to introduce a new instrument for secondary aerosol formation studies! The New Dekati® Oxidation Flow Reactor DOFR™ is a constant flow oxidation flow reactor based on the TSAR system (Tampere Secondary Aerosol Reactor) developed and designed in Tampere University. The DOFR™ is used for the study and research of PAM (Potential Aerosol Mass) and SA formation in various environments. While the SA formation processes can take several days in the atmosphere, the DOFR™ enables study of these processes in a matter of seconds. In the DOFR™, the time scale of the aerosol formation processes is reduced from days to less than a minute by creating highly oxidative conditions for the aerosol sample. The DOFR™ is especially designed to study transient aerosol emissions; the residence time is low and the flow through the oxidation chamber is kept constant and laminar throughout the measurements.
The complete DOFR™ system consists of a sample inlet, a reactor chamber with 12 UVC-lamps and an ejector diluter. The sample first passes through the reactor inlet that is designed to ensure laminar flow through the reactor itself. After the inlet part, the sample enters the oxidation chamber that is made of clear glass and surrounded by 12 UVC-lamps operating at 254 nm. Each of the lamps can be switched ON/OFF to change the intensity of the UVC light which is then measured with a built in UV-sensor inside the unit. An ejector diluter placed right after the oxidation chamber acts as a pump and generates a constant flow through the inlet and the reactor chamber. The ejector diluter additionally dilutes the sample that is then lead to particle measurement instruments such as the ELPI®+ to determine particle size distribution and concentration. The complete system is built into a portable and robust, transportable casing. A separate sample pre-conditioning unit with e.g. ozone production will be available at a later date.