Transmittance
is given by the equation:
T = I/I
o
where I is the intensity of the light after it has gone
through the sample & I
o
is the initial light intensity.
Absorbance
is related to the %T:
A = -logT = -log(I/ I
o
)
Equation Summary
T= (I/I
o
) = 10
-A
%T = (I/I
o
) x 100
A = -log T = log(1/T)
Sample Calculation
If
%T = 95%,
then A = log(100/95) = log(1/.95) = -log(.95)
A = 0.02227
Recall from last week: