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Douglas W. Hamilton Waste Management Specialist Biosystems and Agricultural Engineering. Making Sense of Smells A Guide for Understanding Farmstead Odors. Part 5: Odor Intensity and Offensiveness. How does it smell? How Strong?. Charcter Intensity. Odor Measurement.
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Douglas W. Hamilton Waste Management Specialist Biosystems and Agricultural Engineering Making Sense of SmellsA Guide for Understanding Farmstead Odors Part 5: Odor Intensity and Offensiveness
How does it smell? How Strong? Charcter Intensity Odor Measurement
Two Methods for Intensity • Referencing Suprathreshold • Descriptive Category Scale
Referencing Suprathreshold Odor Intensity Odors are compared to standards of known intensity
Referencing Suprathreshold Odor Intensity Odors are compared to standards of known intensity using dilutions of 1-Butanol
Referencing Suprathreshold Odor Intensity Odors are compared to standards of known intensity using dilutions of 1-Butanol CH3CH2CH2OH
Referencing Suprathreshold Odor Intensity Port 1 2 3 4 5 6 7 8 www.rka-inc.com Purdue Agricultural Air Quality Laboratory
Referencing Suprathreshold Odor Intensity Port vol/vol 1-butanol ppm 1 12 2 24 3 48 4 96 5 194 6 388 7 775 8 1,550 www.rka-inc.com Purdue Agricultural Air Quality Laboratory
Referencing Suprathreshold Odor Intensity Port vol/vol 1-butanol ppm 1 12 2 24 3 48 4 96 5 194 6 388 7 775 8 1,550 www.rka-inc.com
Referencing Suprathreshold Odor Intensity Port vol/vol 1-butanol ppm 1 12 2 24 3 48 4 96 5 194 6 388 7 775 8 1,550 www.rka-inc.com
Referencing Suprathreshold Odor Intensity Port vol/vol 1-butanol ppm 1 12 2 24 3 48 4 96 5 194 6 388 7 775 8 1,550 www.rka-inc.com
Referencing Suprathreshold Odor Intensity Results reported in ppm 1-butanol
Referencing Suprathreshold Odor Intensity Port vol/vol 1-butanol ppm 1 12 2 24 3 48 4 96 5 194 6 388 7 775 8 1,550 www.rka-inc.com
Referencing Suprathreshold Odor Intensity Results reported in ppm 1-butanol Intensity = 105 ppm 1-butanol
Referencing Suprathreshold Odor Intensity Results reported in ppm 1-butanol Log10Intensity = 2.02 ± 0.267 N = 12
Descriptive Scale Odor Intensity Panel rates Intensity on a scale independent of an external standard
Descriptive Scale Odor Intensity • Dilutions of odor are presented to panel.
Descriptive Scale Odor Intensity • Dilutions of odor are presented to panel. • Panelists rate odor intensity on a descriptive scale.
Intensity Scale 0 = no odor 1 = very faint 2 = faint 3 = distinct 4 = strong 5 = very strong 6 = extremely strong
Descriptive Scale Odor Intensity • Dilutions of odor are presented to panel. • Panelists rate odor intensity on a descriptive scale. • Statistics are performed to determine consensus of the panel.
Intensity vs Concentration www.library.thinkquest.org
Measured Swine Odor Relationship 6 = Extremely strong 5 = Very Strong 4 = Strong 3 = Distinct 2 = Faint 1 = Very Faint 0 = No Odor Misselbrook, et al. 1993
Intensity vs Offensiveness www.library.thinkquest.org
How does it smell? How Strong? Charcter Intensity Odor Measurement
How Good or Bad? How Strong? Hedonic Tone Intensity Odor Measurement
How Bad? How Strong? Offensiveness Intensity Odor Measurement
A odor will be equally offensive, no matter how strong. Offensiveness is an Intrinsic Property of an Odor
Offensiveness by Olfactometry • Equal Intensity samples are presented to panel.
Offensiveness by Olfactometry • Equal Intensity samples are presented to panel • Panel rates offensiveness on a descriptive scale.
Offensiveness Scale 0 = Inoffensive 1 = Very faintly Offensive 2 = Faintly Offensive 3 = Definitely Offensive 4 = Strongly Offensive 5 = Very Strongly Offensive 6 = Extremely Offensive
Offensiveness by Olfactometry • Equal Intensity samples are presented to panel • Panel rates offensiveness on a descriptive scale. • Statistics are performed to determine consensus of the panel.