This specification covers a disposable glass Westergren tube used for measuring the erythrocyte sedimentation rate. Covered by this specification are Type I (standard Westergren tube used in conventional racks only) and Type II (self-zeroing tubes used with racks that have convenient disposable tube features) Westergren tubes. The tubes shall be manufactured from borosilicate glass (Type I, Class B) or soda lime glass (Type II) into a one-piece construction that is free from visible defects, straight, and of uniform bore, with the ends of the tube cut at right angles to the tube axis and fire polished. In addition, Type II tubes shall be inserted wit an absorbent cotton plug. The tube shall be graduated, with graduation lines at right angles to the tube axis and in units of millimeters.