BROOKFIELD Operation Manual R/S SST2000 Soft Solid Tester 1 of 9 \\Bvserver\Data\RS Information\SSTManual.
BROOKFIELD Operating The SST2000 Soft Solids Tester Running a sample using software control 1. In Measure/Analysis click Load Program File and select the required test method. 2. Centre the sample on the base plate and fix in place with the clamps. 3. Lower the instrument head by pushing down on the “periscope handles” so that the vane enters the sample to the required depth. 4. Click Start, enter the required filename for the results and click OK. 5.
BROOKFIELD Configuration Modulus: The upper and lower limits of the range for the modulus regression is defined here as percentages of the peak value. A typical range is 20% to 70% but these should be altered to accommodate longer or shorter linear regions. Creep: The number of points for the regressions for Instantaneous Response and Viscous Response are entered here. Typical values are 5 points and 20 points respectively. Running a sample in Stand-Alone mode. Running a one-off test 1.
BROOKFIELD Editing and Running Programs As detailed in the RS Rheometer operation manual, stand-alone programs can be written under the Utilities → Edit Programs menu for the SST2000 to facilitate fast test turnaround. 4 of 9 \\Bvserver\Data\RS Information\SSTManual.
BROOKFIELD Getting Started In Soft Solids Testing Two test methods are most often used to evaluate soft solids with the SST2000: The Constant Rate Test and The Creep Test. The Constant Rate Test For products like: Stiff pastes, slurries, set gels, waxes. Properties measured: Yield stress or torque, equilibrium stress strain at yield, rigidity modulus. Description: In the constant rate test the vane is rotated at a constant low rotational rate (typically 0.1 to 0.
BROOKFIELD Mayonnaise shows a distinct gel breakdown after the peak yield point. Other samples, such as some pastes and slurries may not peak but equilibrate at an equilibrium stress plateau: Equilibrium stress CR test on toothpaste. Equilibrium stress is an indication of low shear viscosity or “consistency”. The Creep Test For products like: More mobile gels and lumpy products : custard, gravies and sauces, jams and marmalades.
BROOKFIELD Typical results plot: Creep test on fruit conserve. Angular displacement (Phi, radians) is plotted against time. Short timescale response relates to elastic behaviour and long timescale response relates to viscous behaviour. So a high initial angular displacement indicates a flexible “wobbly” gel structure while a steep gradient at long timescales means a product that creeps easily, that is, it has a low low-shear viscosity.
BROOKFIELD Container Dimensions For yield point measurements the container dimensions are largely irrelevant. For creep tests and strain or modulus measurements in constant rate tests the container diameter does come into effect, especially with higher diameter ratios, and must therefore be entered into the measuring system setup details in the Meas-Editor utility program. For diameter ratios of less than 0.
BROOKFIELD Vane Constants For The Soft Solids Tester Stress Constant: τProm. All standard vanes supplied for the Soft Solids Tester have a height (H) to diameter (D) ratio of 2:1. A stress constant is required for each vane to convert torque in Newton metres to shear stress in Pascals. This constant is calculated as follows: τ prom 10−4 H 1 = + 3 πD D 3 −1 The constants for our standard vanes are as follows: Vane V30-15 V40-20 V80-40 Diameter (m) 0.015 0.020 0.040 Height (m) 0.030 0.040 0.
