Adjacent Words

Indicator card definitions

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Webster's 1913 Dictionary

3. (Mech.) The part of an instrument by which an effect is indicated, as an index or pointer. 4. (Zo["o]l.) Any bird of the genus Indicator and allied genera. See Honey guide, under Honey. 5. (Chem.) That which indicates the condition of acidity, alkalinity, or the deficiency, excess, or sufficiency of a standard reagent, by causing an appearance, disappearance, or change of color, as in titration or volumetric analysis. Note: The common indicators are litmus, trop[ae]olin, phenol phthalein, potassic permanganate, etc. Indicator card, the figure drawn by an engine indicator, by means of which the working of the engine can be investigated and its power calculated. The Illustration shows one form of indicator card, from a steam engine, together with scales by which the pressure of the steam above or below that of the atmosphere, corresponding to any position of the engine piston in its stroke, can be measured. Called also indicator diagram. Indicator telegraph, a telegraph in which the signals are the deflections of a magnetic needle, as in the trans-Atlantic system.