Project Details:
Guidelines for shear rheometer calibration and performance check
| Project No.: | 2007-004-1-400 |
| Start date: | 2007-07-01 |
| End date: | 0000-00-00 |
| Division: | Polymer Division |
Objective:
To elaborate simple techniques for calibration and performance checkof rotational shear rheometers. To develop widely accepted guidelinesboth for "ordinary users" and "rheometry experts".
Description:
Although rheometers are usually specified for certain limits (minimum/maximum torque or angular speed), it is often difficult to judge if a rheometrical result is reliable or an artefact. In many cases there are even discrepancies between different rheometers in the same lab. In the project the challenges to produce reliable data will be described using experimental results. Efficient and sensitive test methods will be elaborated and recommendations for suitable reference materials will be given. Physical (shear heating or tool inertia,...) and chemical artefacts (sample ageing, thermal degradation,...) will be demonstrated and discussed. Recommendations for temperature calibration procedures will be elaborated. Aim of the project is to develop widely accepted guidelines for the performance check of shear rheometers and for their calibration. In part 1 of the project simpler rheometrical tests are in focus (viscosity function and dynamic moduli determination) - guidelines for "ordinary users" will be developed. In part 2 more complex measurement modes will be treated (creep/recovery tests, normal stresses, stress relaxation, transient phenomena) - guidelines for "experts" will be developed.
Progress:
January 2012 - A publication for "Applied Rheology" is under work. The title will be "Guidelines for shear rheometer calibration and performance check: Determination of viscosity function and dynamic moduli". It comprises a literature overview, a description of measurement modes and a chapter about rheometry reference fluids, both Newtonian and non-Newtonian. Procedures for exploration of rheometer measurement limits will be discussed and experimental examples will be shown. Furthermore routine calibration procedures for rheometers, in particular for the temperature control will be described. Currently, the task group is preparing the manuscript for submission.