ABSTRACT
Introduction '" 63 Basic Principle of the Hardware 65
The Probe 65 The Control Unit 66 Computers, Printers, and Plotters 66 Basic Mechanical Principle of the Twistometer and DTM 66
Interpreting the Results 68 The Various Rheological Models 68 The Data Processing Modes Used by the DTM 70
The Basic Model Tool 71 The PEXP Curve-Fit Tool 71
Precautions and Remarks 71 Standard Precautions 72
Influence of Probe Position 72 Influence of Preconditioning or Serial Stresses 74
Conclusions 75 References 75
Complete determination of the mechanical properties of a material requires exposing it to a stress that is as clearly defined as possible over a perfectly determined geometry. The simplest example is in determination of the mechanical characteristics of an isotropic material that can be simply deformed by elongation in a single direction. The use of geometrically well-defined test assays then enables determination of all the intrinsic characteristics.
