From a short description of the equipment I guess that your rheometer is an advanced instrument for measuring a variety of rheological properties like steady shear viscosity, dynamic (oscillatory) moduli (elastic moduli), and even normal force differences. I assume that different measuring configurations are available, like concentric cilinder, cone and plate, and parallel plate geometries. In this kind of instrument a variety of the mechanical properties of fluids and semi-solids can be studied in shear deformation.

A first requirement is that you have a basic knowledge of rheology (the science of mechanical properties of materials) and that you are familiar with commonly used terms like shear deformation, shear rate, shear stress, dynamic shear moduli and other. Equally important is that you have an idea about which properties of your materials you want to investigate and what kind of measurements are required to this aim.

Then you can start with some simple tests to explore the nature of your materials. For fluids you can measure viscosity at a number of different shear rates. Depending on whether viscosity varies with shear rate or not you are dealing with a (simple) Newtonian fluid or a (complex) non-Newtonian fluid. For semi-solids (e.g. gels) you may prefer to start with small-deformation oscillatory (dynamic) measurements at a range of angular frequencies) in order to prevent destruction of the structure of your material.

The selection of instrument parameters (measuring geometry, range of shear rates or frequencies) is just a matter of trial and error. They can be estimated by measuring some simple liquids with known viscosity. A range of test fluids is generally available from the instrument manufacturer. Likewise, operational ranges of measuring geometries are indicated by the manufacturer and basic operation of the instrument is described in a manual.

Uladzislau Aharodnikau

Basic Oscillatory Rheolgy screening can be made of

1 - Frequency sweep

1% strain

frequency from 0.1 Hz up to 100 Hz

at a fixed temperature ( 25°C?)

Recording G', G", delta

Outcome : Checking that G' and G"" have linear behavior within this windows of frequencies

2 - Strain sweep

at a fixed frequecny ( from previous window ) : 1Hz per example

strain : from 0.1% up to 100%

(log scale / 5 to 6 points per decade )

Recording G', G", delta

Outcome :

- identify Linear Viscoelactic zone ( at low strain )

- identify strain value for G' cross-over G""

That could be a good start already. To be tuned to your gels for adequate

frequency and strain sweep values. Rheologist would suggest to go for

plan-cone or plan-plan geometries. This will very much depend of your ability to generate gels and place them in the rheometer.