SURFACE TENSION MEASUREMENT METHOD AND SURFACE TENSION MEASUREMENT DEVICE

摘要

In a surface tension measurement method, first, a meniscus (M) is produced at the distal end of a pipette (13) at the boundary between air in the pipette (13) and a to-be-measured liquid (S), once the lower end of the pipette (13) has been immersed in the liquid (S). Next, with respect to laser light (LA1, LA2, LA3) passing through the meniscus (M) and a lens (15) from the upper end of the pipette (13), an optical first distance (L1) between the lens (15) and the distal end of the pipette (13) and an optical second distance (L2) between an aperture (22) and the lens (15) are calculated. The radius of curvature of the meniscus (M) is then calculated on the basis of the first distance (L1) and the second distance (L2). Finally, the surface tension of the liquid (S) is calculated from the pressure applied to the meniscus (M) from air supplied within the pipette (13), the pressure applied to the meniscus (M) from the liquid (S), and the radius of curvature of the meniscus (M).