The Difference Between a Surface Tension Meter and a Contact Angle Gauge

Surface Tensiometers and Video Optical Contact Angle Measurement Instruments are two important analytical instruments in the field of interfacial chemical analysis testing. They are used by material researchers, developers, and quality control personnel to measure surface tension values, interfacial tension values, or contact angle values. However, for a long time, users have raised this question when selecting surface tension instruments and contact angle measurement instruments: Which should I choose, a surface tension instrument or a contact angle measurement instrument?

What are the main differences between a surface tension gauge and a contact angle measurement instrument?

Surface Tensiometers generally refer to instruments that use the weighing principle and employ the Wilhelmy Plate or DuNouy Ring methods. Video Optical Contact Angle Measurement Instruments, on the other hand, typically utilize optical video techniques to capture the lateral profile of a droplet and then analyze the contact angle values through fitting algorithms like the Young-Laplace equation. From the perspective of the tested object, Surface Tensiometers are generally used to measure surface tension and interfacial tension values between liquids and gases or between liquids (e.g., water-oil); while Video Optical Contact Angle Measurement Instruments are commonly used to test the properties of solids, such as contact angle values, surface free energy values, and wettability analysis.

Is there a single instrument that can simultaneously analyze surface tension and contact angle values?

Due to the fact that the weighing principle and optical principle are two entirely different principles, most manufacturers have implemented the two-in-one functionality by either using the weighing principle to test surface tension and contact angle, or by utilizing video optical principles to test contact angles while simultaneously determining the surface tension and interfacial tension values of liquids through the pendant drop or constrained sessile drop methods. A few commercial instrument manufacturers have combined both functions into one.

The surface tension gauge based on weighing principles and the contact angle measurement instrument using video optical principles have been merged into one, offering excellent high-precision control and convenience. As a result, the only shared component between the two instruments is the sample platform's up and down movement. Shanghai Sorin's adhesion analysis module achieves a complete integration of the surface tension gauge and contact angle instrument, making the two-in-one functionality a must-have choice.