Once the value of K is known, the viscosity can be determined by measuring the amount of time the test liquid flows between the two graduated marks. Where \(K\) is the value of a liquid with known viscosity and density such as water. Here are six types of viscosity measurement devices to consider: Falling ball viscometers.
The molecules in vegetable oil form no hydrogen bonds, but their large size means that the London forces are very strong and the liquid is extremely viscous.\) Rubbing alcohol and ethylene glycol (HOCH 2CH 2OH) molecules will have similar London forces, but with two hydroxyl groups, ethylene glycol molecules form twice as many hydrogen bonds as those of 2-propanol, so ethylene glycol is more viscous. Rubbing alcohol molecules (2-propanol) are significantly larger than those of water, so their greater London forces result in a higher viscosity. Explore AMETEK Brookfield Customer Learning Center to learn about viscosity, materials flow behavior, importance of conducting rheological measurements, and more. A method of determining the viability of a gum for use in making a product which comprises: (a) mixing a sample of the gum in a solvent comprising one or more hydroxy moiety containing solvent compound to form a solution containing the gum (b) measuring the viscosity of the solution and comparing against a predetermined target viscosity for. Each of the first three substances can form hydrogen-bonds. The rate of flow of a liquid depends on the magnitude of the intermolecular forces and the shapes of the molecules. Note: The viscosity of the liquids, not the pipets, is being tested. The narrow point in the pipet is responsible for restriction of liquid flow. Unlike rheometers, viscometers only measure the viscosity of fluids under one flow condition.
The associated still images include pictures of the apparatus, labeled samples (from left to right: water, rubbing alcohol, ethylene glycol, vegetable oil), and the tip of pipet. A rheometer is an instrument used to measure the way a liquid flows in response to applied force, whereas a viscometer is an instrument used to measure the viscosity of a fluid.
0 kommentar(er)
