Figure 2.

(a) Mean signal intensity, defined as the average over all 13 detector responses in the electronic nose array to an odorant, plotted vs. the partial pressures of homologous series of alkane and alcohol odorants. (b) Responses, ΔR_max/R_b, of three individual electronic nose detectors [poly(ethylene-co-vinyl acetate), poly(butadiene), and poly(n-butyl methacrylate)] that produced the largest responses to a homologous series of straight chain alkanes, plotted vs. the partial pressures of the odorants in each series. (c) Responses of three individual detectors [poly(ethylene glycol), poly(ethylene oxide), and poly(vinyl acetate)] that produced the largest responses to a straight chain homologous series of 1-alcohols, plotted vs. the partial pressures of the odorants in each series. The alkanes used in a and b were n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, and n-tetradecane. The straight chain alcohols used in a and c were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol. Each odorant was maintained at a partial pressure equivalent to 10% of its vapor pressure, and the background was ambient air. For clarity, the number of carbons in each odorant is indicated for each data point, in italic type for the alcohols and in nonitalic type for the alkanes. The error bars represent one SD unit in the responses to six exposures of each odorant.