1) Measure 2) Measurement 3) Measuring 4) Mensuration 
Densitometry is the quantitative measurement of optical density in light-sensitive materials, such as photographic paper or photographic film, due to exposure to light. Optical density is a result of the darkness of a developed picture and can be expressed absolutely as the number of dark spots (i.e., silver grains in developed films) in a given a...
Densitometry is a technique to help evaluate a patient
A procedure utilizing a densitometer. ... (05 Mar 2000) ... 
(den″sĭ-tom´ә-tre) determination of variations in density by comparison with that of another material or with a certain standard.
Type: Term Pronunciation: den′si-tom′ĕ-trē Definitions: 1. A procedure using a densitometer.
[n] - measuring the optical density of a substance by shining light on it and measuring its transmission
Densitometry is a technique to help evaluate a patients candidacy for hair transplantation and predict future hair loss. It analyzes the scalp under high-power magnification to give information on hair density, follicular unit composition and degree of miniaturization.
noun measuring the optical density of a substance by shining light on it and measuring its transmission