Bohlin announces C-VOR, an advanced digital rheometer and spectrometer system offering triple mode operation: stress, strain, and shear rate from a single test station
Bohlin Instruments has introduced the C-VOR, a new advanced digital rheometer and dynamic spectrometer system capable of running all rheological test modes including step strain testing. The C-VOR is suitable for a very wide range of applications including coatings, foods, pharmaceuticals, polymers and petrochemicals.
The C-VOR is a high resolution, modular system with triple-mode operation which allows strain, stress and shear rate controlled measurements to be performed using a single test station.
The new triple mode motor control enables the C-VOR drive motor to be engaged and controlled as a conventional servo system allowing true strain controlled measurements such as stress relaxation and stress growth.
Alternatively, the motor can be controlled at pre-set speeds to generate shear rate controlled data.
Conversely, by running the motor in open-loop mode, stress controlled tests such as creep and creep recovery can be performed.
The strain-controlled tests are torque re-balanced which ensures that the actual strain perfectly tracks the command strain producing compliance free, true controlled strain data.
In combination with this, the system provides excellent transient control and step changes in strain can be effected in as little as 20 milliseconds.
Incorporation of a high-resolution normal force sensor directly into the C-VOR mechanics gives both extreme sensitivity and a broad range.
This enables precise and accurate normal stress measurement on low viscosity solutions through to high modulus polymer melts.
In addition normal force can be used for active gap control and a range of sample loading protocols. For maximum flexibility, the C-VOR can be quickly and easily configured with a wide range of temperature controls to suit all testing requirements.
Available temperature control units include a range of fluid circulators, a peltier device, electrically heated plates and a forced gas oven with a liquid nitrogen cooling option.
Practically, this means that the C-VOR test station can quickly be adapted as testing requirements change. Flexibility in both measuring sensors and temperature controls means that the C-VOR is equally as capable of measuring solid polymers in torsion as it is in generating viscosity data on low viscosity fluids.
The rheometer is driven by a 32-bit MS-Windows based operating software compatible for use on all modern operating systems including windows 95, 98, ME, NT4, and 2000.
