OU NanoLab/NSF NUE/Bumm & Johnson
Photometric Quantities
•Transmittance (T)
•
•Absorbance (A) (AKA optical density, O.D.)
usually
given in percent
by
convention, base 10 logs are used
In
photometry we measure the intensity of light and characterize its change by and object or substance. This change is typically expresses as percent transmittance or absorbance.
Frequently
when your primary interest is
the light beam
Used
almost exclusively when your interest concerns the properties of the material