Choosing a tolerance

What is a reasonable value for We cannot give a number at this stage, but we can claim that for many applications, reasonably good performance is expected even with high tolerance (less accurate mixtures). As human beings, we are mainly driven by visual and verbal stimuli. Whenever these are in conflict with

olfactory impressions, the brain tends to “twist" these impressions so that they fit the visual or verbal input. This leads to the phenomena known as olfactory illusions, which can be as severe as causing subjects to think they are actually smelling an odorless liquid . Consequently, for the average consumer, poor mimicking ability can be compensated by visual and verbal cues, at least to some extent. For example, sniffng a garlic-like substance while watching a TV pizza commercial, might suffice to convince many viewers that they are actually smelling pizza.