Stalagmometer method
The stalagmometer method is a common method for measuring the relative surface and interfacial tension .
The measurement is based on a geometric calculation. During the measurement, the liquid is pressed out of a cannula or flows through a specially shaped capillary tube, at the end of which the drops slowly fall. The gravimetrically or volumetrically recorded drop mass allows the calculation of the surface tension. In doing so, use is made of the fact that the drop size of a liquid on the draining surface is directly proportional to its surface tension (γ = f · V · ρ / n). The surface tension (γ) results from the flowed volume (V) (whereby a number of droplets (n) were formed), the density (ρ) and a factor f, which is determined by calibration using a reference liquid with a known surface tension.
literature
- Kurt H. Bauer, Karl-Heinz Frömming, Claus Führer: Textbook of Pharmaceutical Technology. With an introduction to biopharmacy. 8th revised and updated edition. Wissenschaftliche Verlagsgesellschaft, Stuttgart 2006, ISBN 3-8047-2222-9 .
Individual evidence
- ↑ IMETER .: Interface and surface tension