Brookfield R/S Coaxial Cylinder Rheometer - Manual (Page 39)

Brookfi eld Engineering Labs., Inc. Page 39 Manual No. M08-219-B1211
Preset value as a function of time:
D[1/s]=f(t)
0
20
40
60
80
100
0 60 120 180
t[s]
D[1/s]
A standard measurement is shown in the following example:
1st step: shear rate increases within 60 sec from 10.00 to 100.00 s -1 .
2nd step: shear rate remains at 100.00 s -1 for 60 seconds
3rd step: shear rate decreases from 100.00 back to 10.00 s -1 within 60 seconds
This measurement consists of three steps, each lasting 60 seconds and containing a number of
measurement points.
The following is an example to explain the input of a program.
Apart from the shear rate D [s
-1 ] = f(t), the preset value can also be defi ned as:
speed n [rpm] = f(t)
torque M [‰] = f(t) and
shear stress Tau [Pa] = f(t)
Steps are always linear, measurement points are also defi ned as linear; i.e. logarithmic steps are
not possible. For logarithmic measurements, you will need the Rheo 3000 software.
Preset value sub-steps in a defi ned step according to the following equation:
Preset Value = End Value - Start Value/(Number of Measuring points - 1)
The fi rst user defi ned value (= the fi rst measuring point) is always the start value of the ramp.
The last measuring point is determined as the end value of the user defi ned value range. As in
our example, to reach the values D = 10, 20, 30, ... , 100 [s
-1 ] a starting value of 10 [ s-1 ] is used
with increments of 10, therefore, 10 measurement points are required. To check: 100-10/(10-1)
= 10.
Number of Measurement Points = ((End Value - Start Value) / Preset Value) -1
After the selection of the menu level “Edit Program”, the user will be prompted to select the
program.
•
•
•
•
•
•