Assertion: column's diameter | /r/HasProperty | 2.1 mm
Facets:
Source sentences:
text: V=L*pi*r2, where L = length of column (typically 50-250 mm, or 5-25 cm), and r=radius of the column, where typical internal diameters of HPLC columns are 2.1 mm, 3 mm, 4 mm, and 4.6 mm.