Surface Tension Meter. Bmzl-01 Developed

Surface tension is a significant property of fluid. It is a force which causes by the unbalanced stress of surface molecules, introverted contraction, force on unit length of liquid surface. Its measurement methods are widely used in many fields such as the performance appraisal of surfactant, mixed surfactant, wet paint, pigment, stable emulsion, drugs, cosmetics, ink products, petrochemical products, and the process control of foam separation, distillation, extraction, emulsification, adsorption, madefaction, adhesion, spread, etc. Recently, researchers have proposed a series of improvement and innovation about the measurement methods, which can improve the accuracy and have been used widely.On the basis of previous work, to solve the problems like pressure zero drift, capillary end dip into the sample depth and the bubble velocity is difficult to accurately control, this paper has developed a new experiment device using maximum bubble pressure method. And this device has a good perfromance in measurement and operation. The measurement results of Cross-sectional area of ethanol and n-butanol molecules was2.6-3.0×10-19m2, which was consistent with the literature value (2.4-3.2×10-19m2).Followings are the works and achievements of the research in theory, technology and implementation:1. Improved the micro-pressure generating device. Use the airtight tank with submersible pump to generate constant and tiny pressure. This can solve the problem of pressur zero drift.2. Improved the bubble velocity adjustment device. The existing device has difficulties in fine adjustment, and the proposed device, which used the reduction gears to adjust the velocity, is good in fine-tuning, even the velocity is low to0-0.2mL/min.3. Improved the sample liquid level adjustment device. This paper has proposed two kinds of adjustment device, lift platform kind and vertical rotation kind. Both can eliminate the measurement error caused by the depth of capillary end dip into the sample.4. Improved the micro-pressure measurement device. Use the wind pressure type gauge which has a measure range as±900.0Pa. And this gauge has several advantages like sensitive reaction, accuracy and convenience.5. Improved the constant temperature control device. Use the slide block type design and the temperature control precision reaches±0.1℃. 6. We measured the relation between the surface tension and the concentration of ethanol, n-butanol aqueous solution, fitted the experimental data using Origin, the correlation coefficient reaches0.999and the accuracy is no less than±0.01mN/m.