Rotary rheometer DVNext

laboratory

The DVNext Wells-Brookfield Cone/Plate 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. FEATURES AND BENEFITS Determine absolute viscosity of small samples (0.5–2.0 mL) Precise shear rates for determining a material's flow curve behavior Rapid temperature control due to small sample size Optional magnetic coupling attachment for simplified spindle attachment and removal Electronic gap adjustment for simplified setup and increased throughput Touch Screen Display available on DVNext Rheometers 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% of full-scale range Repeatability: 0.2% of full-scale range PRINCIPLE OF OPERATION The DVNext Wells-Brookfield Cone/Plate 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. 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.