What Is a Penetrometer?

An instrument used to measure the osmotic pressure of a polymer solution to measure its molecular weight. There are two solution pools. One is connected to a capillary tube, and the lower portion is in contact with the other solution pool through a semi-permeable membrane. The pressure and molecular weight can be obtained from the difference between the two liquid levels. The area of the semipermeable membrane of the osmometer should be large, and the capillary should be thin, so that it takes less time to reach equilibrium. There are many types. The newer series is a fast automatic balance osmometer, which can automatically adjust the position of the solvent storage tank, so that the solvent can immediately reach the equilibrium with the solution. The direction of solvent flow can be indicated by bubbles in the capillary tube, and the servo motor is driven by the photoelectric detection tube to make the solvent storage tank rise and fall to balance. The osmotic pressure can be calculated from the height difference between the liquid level of the storage tank before and after the solvent and the solution come into contact.