Abstract: Liquid interfacial tension coefficient is one of the important physical parameters and realizing the precise measurement of the interfacial tension coefficient of liquid has important application value. We design a new set of liquid interface tensiometer on the basis of the original instrument. The instruments of this kind with optimized suspension girder structure realizes effective amplification of the surface tension，and the introduction of magnetic levitation technology and Hall element displacement detection system can realize accurate measurement of liquid surface tension method. The designed apparatus has simple structure，measurement precision and repeatability.

Key words: interfacial tension, magnetic suspension, scale arm, Hall displacement detection