The trained canine and handler team remains the most widely used and successful detection system in the world (1). The institute for Biological Detection Systems (IBDS) at Auburn University has previously reported the design and testing of a quantitative vapor delivery device to study canine olfactIon (2). These devices provide a controlled odor delivery environment invaluable in the study of olfaction. Termed olfactometers, these delivery systems are not confined to a singular design or experimental purpose (3). To determine olfactory threshold levels, for example, a device which delivers a single odorant over a large concentration range would be the design of choice (cf. Ref. 2). However, the formulation of an effective vapor signature as determined by canine olfactory performance would require a device capable of delivering more than one odorant, yet a broad concentration range of these odorants is not necessary. This paper will discuss both of these olfactometer designs: a single-source olfactometer (550) and a multi-source olfactometer (MSO). Specific criteria have been formulated by which olfactometers are designed for psychophysical research which include the purity of diluent gas and the ability to precisely control the onset and termination of an odor (4). The IBDS olfactometers are based, in part, on previous olfactometer designs utilizing mass flow controllers, a purified air diluerit and a controlled temperature environment (5). The effectiveness of the IBDS olfactometer design as applied to these criteria for psychophysical research has been reported (cf.Ref. 2). However, the following work expands on this initial study by outlining performance specific testing in order to characterize such time-dependent parameters as odorant rise time and output stability under operational conditions, which were not included in previous reported studies. These time.dependent parameters for both MSO and SSO olfactometer designs will be compared by two different realtime detection methods, ion mobility spectrometry and photo-ionization detection.