1. An instrument for measuring the density of a fluid.
2. An instrument for measuring, by virtue of relative turbidity, the growth of bacteria in broth; useful in microbiologic assay of nutrients and antibiotics, phage studies, etc.
3. An instrument for measuring the density of components (e.g., protein fractions) separated by electrophoresis or chromatography, utilizing light absorption or reflection.
4. An electronic instrument for measuring the blackening of radiographic film by x-ray exposure; used for film sensitometry, bone densitometry, measurement of line spread function (microdensitometer).
Origin: L. Densitas, density, _ g. Metron, measure