The TAPPI T 232 standard specifies a method for the measurement of pulp Fiber length by projection method. This method calculates the weighted average Fiber length by dispersing pulp fibers on a projector, measuring the projection length of the fibers. The projection method is simple and fast, and is suitable for many pulp types such as chemical pulp and mechanical pulp. Fiber length is an important factor affecting paper strength, flexibility and processing performance. This standard provides a scientific Fiber length detection method for the paper industry and is widely used in pulp quality control, process optimization and product development.