Abstract
Many states have enacted stringent regulations to control the odor emissions from agricultural processes. A scentometer is used for measuring these emissions, but this method does not accurately characterize an odor in terms of frequency, intensity, duration and offensiveness. An electronic nose can more accurately characterize an odor profile. The objectives of this project were to use components of swine manure and a solution that closely resembled the odor profile of swine manure to test the capability of a redesigned electronic nose. Headspace gas chromatography was used to correlate the sensor responses to actual measured values of a particular compound in the headspace. The electronic nose was able to detect all the compounds used in this experiment. This included fatty acids (butyric, isobutyric, valeric, and isovaleric acids), alcohols (p-cresol and isoamyl alcohol), sulfides (dimethyl sulfide and dimethyl disulfide), and butanal. Using ANOVA and PCA techniques, it was determined that the sensors could detect concentration changes in all the compounds except for butanal. In addition, a linear response was observed for most increasing concentrations of compounds. At dilute concentrations the response was determined to mimic Henry's Law. Finally, sensor response and variance was also observed to understand the manner in which a large dimensional model can be reduced without losing qualitative data. Taguchi sensors 824 and 815 showed the best correlation to concentration increases in the swine manure solution. Sensors 824 and 800 showed the least variance in their responses to the swine manure solution.
Bausch, Carrie Lynn (2000). Development of electronic nose for measurement of agricultural odors. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -B38.