ASTM International Standard Specification for Glass Westergren Tube, Reusable ASTM E923-97(2013)

This specification covers the design and dimensional requirements for reusable glass Westergren tubes that measure the erythrocyte sedimentation rate (ESR), which is the suspension stability, or amount of settling after a specified time, of red blood cells in diluted, anti-coagulated human blood. The tubes shall be fabricated from Type I, Class B borosilicate glass, or Type II soda lime glass. Tubes shall comply with requirements for graduation line length and numbering, marking permanency, grinding bevel, and workmanship. The tubes should also pass a pigmentation and amber stain test.