A NEW DEVICE FOR THE SIMULATION OF INDOOR AIR-POLLUTION SOURCES

A reliable and flexible generation system for volatile organic compoun ds is a valuable tool for indoor air researchers, for instance, in the context of investigations on interactions between organic vapors and indoor materials. A new VOC vapor generation system has been developed and tested for its applicability in indoor air research. it is based on a modified droplet ejector working on the principle of a piezoceram ic ink-jet printer. Different solutions, consisting of complex mixture s of compounds, were used for performance testing of the system. The c ompounds covered a wide boiling point range and included lipophilic an d hydrophilic substances. Emission rates have been generated in the ra nge from 8 mu g/h up to 7.7 mg/h per compound, simulating indoor emiss ion sources from low to high emission potential. Emission rates monito red over >90 h showed relative standard deviations <2% for most compou nds, being close to analytical uncertainties. The system shows a very high flexibility with regard to number and choice of compounds to be e vaporated, their relative concentrations, the total emission rate, dow n to indoor relevant values, and together with good emission constancy and high precision allows for numerous applications.