The Model TDD 590 thermodenuder is designed to remove moisture and volatile particles from an aerosol sample for the subsequent measurement of dry particle size. There are a lot of industrial applications the particle size distribution of hot gases is interesting for.
The specification of many particle size measuring instruments does not allow analysing gas with high temperatures which required a cooling of the sample. When cooling takes place condensation processes will occur and volatile particles can be formed by nucleation. Both processes produce particles or change particle size of solid compounds in the gas by heterogeneous condensation on particle surfaces. So results of particle measurements include a systematic error.
For avoiding such measuring errors thermodenuders are used. By regulating the sample temperature such devices enable reducing moisture as well as volatile particles in the sample aerosol flow. Thus condensation processes during cooling down are widely prevented.