Surface tension measurement by the ring method (Du Nouy Method)

Principles and Objectives:

Strength is measured on a ring, using a torsion measuring device, just before a liquid film tears. The surface tension is calculated from the ring diameter and tearing force. 

The experiments conducted are intended for measuring the surface tension of olive oil based on temperature and water/methanol mixtures based on the mixing ratio.

- Magnetic stirrer with heating and 30 mm magnetic bar, cylindrical - Torsion dynamometer, 0.01 N - Ring for measuring surface tension - Stand, base 210 x 130 mm, height 750 mm - Support rod, stainless steel 50cm, M10 thread - Universal clamp / Double nut - Borosilicate crystallizer, 150 mm / borosilicate, 125 mm - Silk thread, l = 200 m / Glass tubes, straight, l = 150mm, 10 pieces - 1-way faucet, straight / Silicone hose, inner diameter 7 mm - Graduated pipettes 10 mL + 20 mL / Safety pipette bulb, up to 100 mL / Pipette tray - Graduated cylinder, 100 / 1 mL - Ethyl alcohol, 500 mL / Pure olive oil, 100 mL / Distilled water 5 L