The platinum plate method of the interfacial tensiometer measures the equilibrium value of the interface (or surface) tension of the liquid, and the platinum ring method measures the maximum force value of the interface (or surface) of the liquid. In comparison, the platinum plate method has the following advantages:
1. It is convenient to measure the surface tension of medium and high viscosity liquids: the platinum ring needs to be lifted upwards during the platinum ring method test. In this process, in addition to the effect of surface tension, there is also the effect of viscous force;
2. High test accuracy: the platinum plate is not easy to deform, and the platinum ring is too easy to deform. The irregular circle and unevenness of the ring will affect the test accuracy of the interface (surface) tension;
3. The platinum plate method can measure the change of the liquid interface (or surface) tension with time: the platinum plate method is always in contact with the liquid to be measured. As long as the interface (surface) tension of the liquid changes, the test value will change. If the data processing software is used, the change curve of the interface (surface) tension with time can also be observed;
4. Easy to use: The test value of the platinum plate is the surface tension value, which does not need to be converted; the test value of the platinum ring is the maximum force value, which needs to be converted. The platinum plate is easy to clean and not easily deformed.