A rapid procedure for selecting attenuators for IITRI dynamic dilution olfactometers

Dynamic dilution olfactometers provide a range of odor dilutions for presentation to panelists. Reliable odor thresholds of source emissions can be evaluated consistently only if the unknown odor thresholds fall in the middle of the dilution range of the olfactometer being used for a given test. This paper describes a fast and reliable procedure for ensuring that individual panelist thresholds will fall in the middle of the dilution range through selection of appropriate attenuators. The recommended approach makes use of the best capabilities of the ASTM and IITRI methods. It has been tested successfully with acetic acid vapors.