www.davidson.com.au - Brookfield Viscometers, Rheometers & Texture Analysis

Determine absolute viscosity of small samples (0.5 - 2.0 mL)
Precise shear rates for determining a material's flow curve behaviour
Rapid temperature control due to small sample size
Electronic gap adjustment for simplified setup and increased throughput
Available on DV-III Ultra Rheometer and DV-II+Pro and DV-I+ Viscometers
Auto-zero function to ensure precision torque measurement
Auto-range function to define full scale range (FSR) for all spindle/speed combinations
Torque measurement accuracy: 1%
Repeatability: 0.2%
Versatility of application: The Wells-Brookfield Cone/Plate Viscometer/ Rheometer provides a wide variety of shear rates and viscosity ranges, which can be further extended by the use of interchangeable cone spindles. Different models can be selected to meet the specific range of viscosities and shear rates required.

The Wells-Brookfield Cone/Plate Viscometer/Rheometer gives researchers a sophisticated instrument for routinely determining absolute viscosity of fluids in small sample volumes. Its cone and plate geometry provides the precision necessary for development of complete rheological data.

Principle of Operation
The Wells-Brookfield Cone/Plate Viscometer/Rheometer is a precise torque meter which is driven at discrete rotational speeds. The torque measuring system, which consists of a calibrated beryllium-copper spring connecting the drive mechanism to a rotating cone, senses the resistance to rotation caused by the presence of sample fluid between the cone and a stationary flat plate.

The resistance to the rotation of the cone produces a torque that is proportional to the shear stress in the fluid. The amount of torque is indicated either on a dial or digital display, depending on model. This reading is easily converted to absolute centipoise units (mPa·s) from pre-calculated range charts. Alternatively, viscosity can be calculated from the known geometric constants of the cone, the rate of rotation, and the stress related torque.

The correct relative position of cone and plate is obtained by following a simple mechanical procedure without the need for external gauges or supplementary instrumentation. The stationary plate forms the bottom of a sample cup which can be removed, filled with .5 ml to 2.0 ml of sample fluid (depending on cone in use), and remounted without disturbing the calibration. The sample cup is jacketed and has tube fittings for connection to a constant temperature circulating bath. The system is accurate to within ±1.0% of the working range. Reproducibility is to within ±0.2%. Working temperature range is from 0°C to 100°C.

Various cone spindles are available for use with the Wells-Brookfield Cone/Plate instruments. One cone spindle is provided with the instrument and is calibrated for use with the sample cup. Additional cone spindles may be purchased and will be calibrated for use with the same sample cup... (for complete details refer to the pdf datasheet).