Brookfield R/S-SST Rheometer - Manual (Page 6)

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Mayonnaise shows a distinct gel breakdown after the peak yield point. Other
samples, such as some pastes and slurries may not peak but equilibrate at an
equilibrium stress plateau:
CR test on toothpaste.
Equilibrium stress is an
indication of low shear viscosity
or “consistency”.
The Creep Test
For products like: More mobile gels and lumpy products : custard, gravies and
sauces, jams and marmalades.
Properties measured: Instantaneous compliance/strain, low shear viscosity/creep
rate, elasticity index.
Description: A single stress/torque is applied at time t=0 and maintained on the
sample over a period of time, usually between one and five minutes. The degree of
subsequent movement in the sample, is recorded against time in the form of angular
displacement (in radians), strain (unitless) or compliance (strain divided by applied
stress – in m
2
/N).
Example method: A constant stress of 1250Pa is applied over a period of 120
seconds. 60 data points are collected over this period.
Equilibrium stress