REOMETRA (Greek rheos a current, a flow + metreo to measure, measure) — devices for measurement of a gas rate — amounts of the gas proceeding on the pipeline (channel) in unit of time. Are applied at a dignity. - a gigabyte. and toksikol. researches (sampling of air; check of a gas leak, napr, at control of density of a prileganiye of pressure vent valves in gas masks and tightness of various closed gas systems; measurement of volume of gas in the closed space at the established gas rate, in installations for chlorination of water, and also in systems where it is required to adjust quickly a gas rate). Under production conditions R. apply during the mixing of gases in certain concentration for the purpose of flow control of each component of gas mixture, napr, at their simultaneous giving in the camera (in a vessel or other capacity). Rubles are widely used in gas, chemical, metallurgical industry.
The river consists (fig. 1) of a tube with the narrowing device (a diaphragm or a capillary) attached to the channel on Krom gas, the liquid manometer and a scale strengthened on a support flows. The narrowing device creates hydraulic resistance, for the Crimea pressure decreases; the size of pressure difference depends on a gas rate, is perceived by the manometer and is determined by a scale, otgraduirovanny in terms of a gas rate or in relative units; in the latter case indications of the manometer transfer to units of a gas rate (according to the tables or traffic attached to R.).
Rubles with a diaphragm apply at measurements of a gas rate from 0 to 160 l • mines - 1 ; River with a capillary — at measurements of a gas rate from 0 to 10 l • mines - 1 . At a big measuring range of a gas rate apply R. with a set of replaceable capillaries of the different sizes to increase in accuracy, each of to-rykh is expected a certain range. For measurements of a gas rate with the increased accuracy from 0 to 0,06 l • mines - 1 mikroreometram with the inclined micromanometer (fig. 2) use. Existence of various types P. allows to select them at sanitary and hygienic researches (see) depending on speed of response between an absorber and the absorbed substance.
Depending on character of a research the manometer P. is filled with water, alcohol, mercury and other liquids, to-rye do not enter chemical interaction with the passing gas. In a gas flow, the expense to-rogo is measured, there should not be drops of moisture (impurity level of liquid in a vaporous state without condensation at measurements is allowed). The gas flow shall be constant (uniform); at a fluctuating flow it is not possible to measure a gas rate by means of R. because of fluctuation of liquid in the manometer. The river is checked on the model device.
Before R.'s use wash out the solvent, then alcohol or distilled water corresponding to the filled liquid and dry. Liquid is filtered and entered into R. in the small portions by means of a pipette, watching that all liquid flew down from walls of a tube. Compensate by movement of a scale deviations of a fluid level from zero situation. Walls of a tube of the manometer and especially narrowing device in order to avoid additional errors at measurements shall be pure. The clearing of the narrowing device in the mechanical way, napr, cotton wool, is not allowed. During the transportation and long storage of R. exempt from liquid, wash out, dry and in order to avoid a contamination in openings of a tube of R. put tampons from cotton wool.
Bibliography: Kremlin P. P. Flowmeters and counters of quantity. L., 1975; M and N x A. A. Methods of hygienic researches, M., 1971; P e regud E. A. Sanitary and chemical control of the air environment, JI., 1978.
N. S. Mironova.