RHEOMETER
A rheometer is an instrument that measures how a substance moves when forces are applied to it. This is called the rheology of the substance. A viscometer measures how hard it is for fluid to change shape at a certain rate. This gives only one value for the fluid: its viscosity.
Rheology is the study of how things flow and change shape when forces are put on them. A rheometer is often used to measure these things. Rheological properties can be measured on all kinds of materials, from fluids like dilute solutions of polymers and surfactants to concentrated protein formulations, semi-solids like pastes and creams, molten or solid polymers, and asphalt.
Principle:
The way a rheometer work is based on the principle of rotational motion, which is to get a simple shearing flow, control the strain rate in terms of the applied strain rate, which is rotation, and then measure a resulting couple of torque. Measuring the material’s resistance to a shear rate is called “shear resistance.” Approaches to design are different, and most of the time, there is no analytical way to convert material properties into basic units.
Uses:
- A rheometer is a device used in the lab to measure how a dense fluid moves when forces are put on it.
- By putting a sample through different kinds of stress, the rheometer can figure out how complex a material’s flow is.
- In addition to mechanical properties, rheology can help figure out how stable a complex food formulation is and how long it will last before going bad.
- The stability of a system like food dispersions can be predicted by measuring the viscoelastic properties of the formulation.
Types:
- Two kinds of rheometers are very different from each other. Rotational or shear rheometers control the shear stress or shear strain that is applied, while extensional rheometers control the extensional stress or extensional strain that is applied.
- A capillary rheometer is a piece of equipment that is used to measure shear viscosity and other flow properties. Capillary rheometers for plastics are piston-die systems that measure the viscosity of polymer melts based on their temperature and how fast they change shape.
Using Rheometer to Measure:
A rheometer is used to find out how a material behaves in terms of its rheology. They measure the measuring bob’s torque and how much it bends. This means that, when measuring viscosity, the rheometer sets a certain amount of current that corresponds to a certain amount of torque.
