A butanol olfactometer for field measurement of ambient odors

Abstract

A portable 1-butanol olfactometer was developed for quantifying odors in ambient air. Panelists compare the intensity of ambient odors with the intensity of discrete levels of 1-butanol provided by the olfactometer. Range of delivered 1-butanol concentrations Is 0 to 80 ppm in air at a flow rate of 15 L/min. Laboratory tests were performed to ascertain overall precision, consistency of panelist responses, uniqueness of each odor step, variability between two Identical olfactometers, and effect of delivery method. For 855 pairs of matched odor Intensities, the ratio of measured butanol concentration to set concentration averaged 0.984 or —0.023 scale steps (where the scale steps differ In concentration by factors of two). In field experiments the equivalent ambient odor Intensities determined by odor panels using the butanol olfactometer ranged from 1.5 ppm to 64 ppm of 1-butanol vapor In air. The precision of ambient odor measurements was within one-half scale step on the 1-butanol olfactometer, sufficient for most odor investigation and abatement research applications. © 1984 Air & Waste Management Association.