We describe a prototype scalable viscometer aimed at facilitating rapid measurements of multiple samples. The device simultaneously measures the viscosity of four samples in an array of Couette cells. Each cell contains a rotor with an embedded permanent magnet that is driven by an oscillating magnetic field generated by a 2-axis Helmholtz coil. The angular displacement of the rotors is recorded by a CCD camera. Image analysis determines the amplitude and phase of the rotors with respect to the coil s sinusoidal current. The viscosity of each sample influences the amplitude and phase of the rotor, which can be predicted with a viscously damped oscillator model. We present data for Newtonian fluids with viscosities from 50 to 2,000 mPa s. The results suggest that our approach can be extended to non- Newtonian fluids.
Citation: Measurement Science & Technology
Issue: No. 1
Pub Type: Journals
combinatorial methods, combinatorial viscometer, Couette cell, high throughput materials testing, magnetic rheometer, rheology