TASIMETER
\tˈasa͡ɪmˌiːtə], \tˈasaɪmˌiːtə], \t_ˈa_s_aɪ_m_ˌiː_t_ə]\
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An instrument invented by Mr. Edison for measuring extremely slight variations of pressure, and by means of these other variations, such as those of temperature, moisture, etc. It depends on the fact that a piece of carbon introduced into the course of an electric current offers a resistance to the passage of the current, which diminishes in a very marked degree in proportion to the amount of pressure exerted on the carbon. A small disc of carbon and another of vulcanite are held together between two platinum buttons, which may be brought into connection with a galvanic battery, and a strip of some substance like gelatine, which contracts and expands with great readiness, is so placed that by its variations in magnitude it varies the pressure on one of the platinum buttons, and hence on the carbon disc. The variations thus produced in the force of the electric current are measured by a very delicate galvanometer, which is also placed in the circuit. So delicate is the instrument that the heat of the band held a few inches off causes a deflection of the needle; while by a slight alteration in form the weight and vital heat of the minutest insect may be determined.
By Daniel Lyons
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ta-sim'e-t[.e]r, n. an apparatus for detecting changes in pressure by the variations in the electrical conductivity of carbon.--adj. TASIMET'RIC.--n. TASIM'ETRY. [Gr. tasis--teinein, stretch.]
By Thomas Davidson
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Electrical apparatus for measuring changes in temperature, moisture, &c. Hence tasimetric a. [Greek]
By Sir Augustus Henry
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