| indicators and reagents | Substances used for the detection, identification, analysis, etc. Of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., colour, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidisers, reducers, fluxes, and colourimetric reagents. (12 Dec 1998) |
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| indicatrix | <microscopy> A three-dimensional construction of the optical relationships in a crystal. Radii proportional in length to either refractive index or velocity may be used to represent variations in those values throughout a crystal (or oriented polymer fibres and films). (05 Aug 1998) |