FIELD: oil production, oil refining and other branches of industry where high precision in determination of impurities is required. SUBSTANCE: in agreement with process sample taking member is positioned with inlet hole to meet flow and samples are taken from areas Si formed by conventional division of pipe-line space by planes perpendicular to longitudinal plane X of pipe- line, arranged in symmetry relative to its center. This plane is vertical one for pipe- line located with inclination or horizontally. Centers of inlet hole of each area Si is matched with points placed in symmetry with central axis of pipe-line or are positioned at distance of not more than 0.1 diameter of pipe-line from them. Sample in each area Si is taken in proportion to rate of flow with proportionality factor Ki that deviates from their average arithmetic value by not more than 20%. Device includes sample taking member mounted in pipe-line with inlet hole to meet flow and outlet unit. Inlet hole of sample taking member is made in accord with conditions of taking samples by process described above. EFFECT: reduced to minimum losses of liquid pumped over pipe-line and obtainment of high-quality sample. 3 cl, 7 dwg, 9 tbl
