There are many ways to measure the performance of foam, and the traditional ways include airflow method, oscillation method and agitation method. Modern methods include: near-infrared scanning method, conductivity method, photoelectric method, high-energy particle method, sound velocity method, and microscopy method.

The air flow method and agitation method are introduced according to the way of foam formation.

Airflow method: The device of the Airflow method is a cylindrical quartz tube with a scale and a capillary tube at the bottom. To ensure that the container wall remains dry before foaming, a long necked funnel should be used to extend towards the bottom of the container and add the test solution into the container. During the experiment, after slowly ventilating the container at a constant speed for a period of time, measure the volume of foam produced when the ventilation stops as a measure of the foaming property of the solution. Record the time t1/2 when the foam height decays to half of the original height to characterize the stability of foam. In addition, membrane foaming method is also a type of aeration method. This new method mainly involves compressing the gas as a dispersed phase into the solution through the micropores of the membrane. The bubbles generated are stabilized by the surface active agents in the solution and separated from the membrane surface due to the shear force of gas flow. The advantage of this method is that the particle size of foam is dispersed in a narrow area and changes with the change of membrane pore diameter.