The TAPPI T 227 standard specifies the measurement method of pulp free degree, that is, Canadian Standard Freeness (CSF). The free degree is an important indicator to evaluate the water filtration performance of pulp. The higher the value, the faster the water filtration rate. This method reflects the surface condition and swelling of the fibers by measuring the water filtration rate of the pulp suspension. The measuring instrument is similar to Shore's Beater, but the absolute dry fiber sampling amount during measurement is 3 grams. There are differences between the free degree and the beating degree, but it can be converted to each other. The standard is widely used in the paper industry for inspection in the beating process, the formulation of the papermaking process, and scientific research experiments.