Every rheometer has its limits. Depending on whether it is an air-bearing or ball-bearing rheometer, the measuring limits for the raw data are different. Raw data are torque, speed and angle of deflection. From the raw data, rheological properties such as shear stress, shear rate, and deformation are calculated using conversion factors.
Table 1 shows the measuring ranges for raw values from different rheometers.
Table 1.
| Limits of raw data/instrument |
Torque
range |
Speed
range |
Angle of
deflection setting |
Angle
resolution |
RheolabQC ball bearing
rheometer |
250 µNm to 75 mNm |
0.01 to 1500 1/min |
- |
2 µrad |
MCR 51 ball bearing
rheometer |
250 µNm to 125 mNm |
10-5 to 3000 1/min |
1 to 8 |
0.01 µrad** |
MCR 101 air bearing
rheometer |
0.1 µNm to 150 mNm |
10-6 to 3000 1/min |
1 to 8 |
0.01 µrad** |
MCR 301 air bearing
rheometer |
0.05 µNm to 200 mNm |
10-7 to 3000 1/min |
0.1 to 8 |
0.01 µrad** |
MCR 501 air bearing
rheometer |
0.05 µNm to 230 mNm |
10-7 to 3000 1/min |
0.1 to 8 |
0.01 µrad** |
MCR 501s air bearing
rheometer |
0.05 µNm to 300 mNm |
10-7 * to 3000 1/min |
0.1 to 8 |
0.01 µrad** |
* at a speed of 10-7 1/min one rotation would take 6944 days
** the resolution corresponds to 7 cm along the 42000 km long equator
Table 1 Limits of raw data for RheolabQC, MCR 51, MCR 101, MCR 301 and MCR 501.
How Do I Recognize Measuring Limits?
In most cases you will recognize measurements which are at the limit or outside of the measuring range by looking at the measuring curves. They do not have a constant slope, show fluctuations in the measuring points or have a bend which can be particularly pronounced.
I recommend always displaying the status messages in the measuring value table in the RheoPlus software. Status messages such as M- or M+ show results which are outside the upper or lower torque range.
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This information has been sourced, reviewed and adapted from materials provided by Anton Paar GmbH.
For more information on this source, please visit Anton Paar GmbH.