TA Instruments AR 2000, Operator'S Manual, Page: 59 / 144

AR 2000 Operator's Manual
5 9
The ratio R
1
:R
2
= R
3
:R
4
. The shear
rate is then calculated as in Figure
6.3 using R
3
and R
4
.
Using the
Stress and Shear Rate Factors
The TA Instruments operating system software calculates the stress and shear rate factors, which are used by
the software in all subsequent calculations.
However, there may be occasions when you will need to enter these factors manually. If you do, follow the
sequence given below:
1. Multiply the angular velocity (
ω
) by the shear rate factor ( F ) to obtain the shear rate (s -1 ).
2. Multiply the angular displacement by the same factor to obtain the strain (dimensionless).
3. Multiply the torque (T) (µNm) by the shear stress factor ( F
σ
) to obtain the shear stress (Pa).
Figure 6.5
Double Concentric