Blood sedimentation capillary tube - has spherical segment piece at stipulated blood level marking permitting suction of air but not liq.

摘要

The blood sedimentation tube has a special piece shaped as a spherical segment pushed into the upper end of the capillary. It makes possible the drawing in of blood by suction until a stipulated level in the blood column has been reached. It also prevents a too rapid return of the blood. The spherical segment piece is inserted with its outer curvature facing downwards to the stipulated level marking. It permits the suction of air through gaps between its edge and the capillary inner walls, but not the suction of liq. that has a higher resistance to air streams.