PIPETTES (fr. pipette) — portioning devices for exact measuring off of small volumes of liquid.
Items depending on their appointment are issued with a capacity from 0,5 to 200 ml, and also 0,1 and 0,2 ml (micropipet); are made of glass tubes with a diameter from 6 to 20 mm.
Distinguish P. straight lines, with expansion, with expansion and a reserve tank, on full discharge of liquid (without divisions), on full or partial discharge (with divisions, or the graduated P.) and capillary. Items without divisions represent glass tubes, nek-ry with expansion in the middle, to-rye are filled in with the measured liquid to an upper tag. The graduated P. — the glass tubes narrowed since one end at which on a certain site divisions are evenly put; such P. allow to measure different volumes of liquid within the capacity of the Item. Pipettes only with an upper tag are counted on full discharge of liquid which volume corresponds to this P.'s capacity (see also Portioning devices , Laboratory glassware ).
In laboratory and clinical and pharmaceutical practice, and also for a nosotrophy P. in the form of glass tubules with the cut-off or delayed nose and a rubber barrel on the opposite end or without it are used. These P. are intended for measuring off of liquids by drops (see. Dropper ).
Bibliography: Kabatov Yu. F. Medical merchandizing, page 129, M., 1977; Katz A. M. and Kantorovich A. S. Measured and portioning devices for clinical diagnostic laboratories, L., 1970; Pravdin P. V. Laboratory devices and the equipment from glass, M., 1978.
V. I. Belkevich.