A Cobb Sizing Tester is a tool used to measure the water absorbency of paper and paperboard. It is used to determine the amount of water that can be absorbed by a paper or paperboard in a given time period. The tester typically consists of a cylindrical drum, a pressure mechanism, and a scale or digital readout to measure the weight of the water absorbed.

The Cobb sizing tester works by immersing a sample of paper or paperboard in water and then applying pressure to the sample to remove any excess water. The sample is then weighed to determine the amount of water absorbed. The test is usually done in a specific period of time, usually one minute, and the results are usually expressed in units of weight, such as grams or ounces, per square meter (g/m² or oz/ft²).

The Cobb sizing tester is commonly used in the paper and pulp industry to evaluate the water absorbency of paper and paperboard products, such as corrugated boxes, paper bags, and other similar items. It's an imp