Excerpts from The Art and Technology of Perfumery workshops held in Bangkok March 2012. Session on what odour strength means from the ABCs of Perfumery a systematic method of perfume creation.
A note: this is done by considering the linear evolution f(x) function of the smell, right? So, the area becomes a triangle. But if f(x) is non-linear (which, for me, is what we see in most odour scenarios), like a logarithmic decay for instance, this won't work. So, the more precise calculation is done by the calculating the definite integral for f(x). The problem here is how to to define these f(x) for each odour (how many smell samples and with objetive impact values for each time). Maybe with some sort of electronic nose advances this can be achieved. So, I am assuming this is only a simplification, so one can have a number to work with.
By surveys. It is averaged out. Think of crowd wisdom. If you have a jar of jelly beans, and you ask 500 people who many beans are in the jar, you will get a range of guesses. The average of all the guesses will be very close to the real number. This applies to many things like people judging distance, speed, etc.
A note: this is done by considering the linear evolution f(x) function of the smell, right? So, the area becomes a triangle. But if f(x) is non-linear (which, for me, is what we see in most odour scenarios), like a logarithmic decay for instance, this won't work. So, the more precise calculation is done by the calculating the definite integral for f(x). The problem here is how to to define these f(x) for each odour (how many smell samples and with objetive impact values for each time). Maybe with some sort of electronic nose advances this can be achieved. So, I am assuming this is only a simplification, so one can have a number to work with.
Well, interesting and fascinating. But a question comes to my mind. The decay is not linear so.:.. formula is rough aproximation
How is the impact number determined?
For what I have understood, it's subjective.
By surveys. It is averaged out. Think of crowd wisdom. If you have a jar of jelly beans, and you ask 500 people who many beans are in the jar, you will get a range of guesses. The average of all the guesses will be very close to the real number. This applies to many things like people judging distance, speed, etc.
how do i know which oil comes under which note (top, mid, base)
Don't consider this.