Viscometer for low frequency, low shear rate measurements
Robert F. Berg, Michael R. Moldover
We describe a torsion-oscillator viscometer whose low frequency ( 0.5 Hz) and very low shear rate (0.05 s-1) are required for measurements of shear sensitive fluids such as microemulsions, polymer melts and solutions gels, and liquid mixtures near critical points. The viscometer has a resolution of 0.2% when used with liquid samples and a resolution of 0.4% when used with a dense gaseous sample. The viscometer operates under computer control and is compatible with submillikelvin temperature control.