Thermo Scientific HAAKE RotoVisco 1 Instruction Manual page 119

Sensor Systems
Note!
The shear rate  in this sensor system alters with the
radius; it is equal to = 0 (R = 0) in the center and has a
maximum value (R = R) at the edge.
The values specified in the table refer to R = R
the edge of the plate. For non-Newtonian samples the
shear stress linked to this value has to be calculated in
order to achieve correct viscosity results.
The following equation applies:

τ = Md ⋅ 3 + n
4
π ⋅ R
τ = Md ⋅ A ⋅ 3 + n
4
or
 (non ) =  (Newtonian)  (3 + n) / 4
-Newtonian
 (non-Newtonian) = Md  A  (3 + n) / 4
log τ log Md
Graphical determination of the structural exponent 'n'.
117

2
A = Shear factor
Md = Torque
3
R = Plate Radius
n = Structural Exponent
of the Ostwald flow law
Δ ⋅ log Md
n =
Δ ⋅ log Ω
Δ log τ
Δ log γ
, i.e. at
R
R
Δ log M
=
.
Δ log Ω
log Ω
.
log γ