The TAPPI T 234 standard mainly specifies the method of determining pulp Fiber coarseness. Fiber coarseness refers to the mass of fibers per unit length, usually expressed in milligrams/meter (mg/m), and is one of the important indicators for evaluating the physical properties of pulp fibers. The standard describes in detail the preparation of samples, the use of testing equipment, measurement procedures, and the calculation method of results. By this method, the roughness of pulp fibers can be accurately determined, providing a scientific basis for paper production and quality control. The standard is applicable to various types of pulp fibers, including chemical pulp, mechanical pulp, and recycled pulp, etc.