Abbreviations and Specific Names. Abbreviations and acronyms based on proper nouns should be written in all capital letters. In most cases, derivative words do not need to be capitalized. This applies to terms based on a professionalâs surname that are used in a general sense today.
Length times width times depth (L x W x D) measures cubic feet and must be measured in feet.
Absorbance is dimensionless, and in particular is not a length, though it is a monotonically increasing function of path length, and approaches zero as the path length approaches zero. The use of the term optical density for absorbance is discouraged. In physics, a closely related quantity called optical depth is used instead of absorbance: the natural logarithm of the ratio of incident to transmitted radiant power through a material.