I am trying to research the attenuation of light through colored liquids, in particular Ribena. I used a colorimeter with varying Ribena concentrations and a steady pH value to gain some absorbency values. I am struggling to find a relationship between absorbency and attenuation. I would like to convert the absorbency values I have collected into a way in which I can apply the formula I=I0e-ux. This will allow me to investigate the relationship between the attenuation co-efficient and the concentration of Ribena.
Thank-you!
Alexandra

I'm not entirely sure where you're having the problem here, can you elaborate? :)

Attenuation is just the measure of the amount of light that is not transmitted. i.e. it is the amount of light that is both reflected or absorbed.

You've pretty much answered my question there. :)
I have collected absorbency values and hit a brick wall because I wasn't sure how to convert that to attenuation but if they're the same thing I should have no problem, right?
So if I wanted to find the attenuation co-efficient, I could just plug in an absorbency value for I?
Thanks again

Well, in the equation you have given there, I=I0e-ux

I would assume that I is the intensity of light transmitted after passing through a thickness of material x, with attenuation coefficient u and original light intensity I0.

Yes I think that's pretty accurate. So, in saying that, are the values I collected for absorbency pointless? Should it have been the intensity of light not passing through the sample I've measured?
Forgive me, I'm struggling to grasp how I could put say a value of 1.2A for absorbency from the colorimeter and compare it with concentration.