Malvern has added the SV-10 Vibro viscometer to its range of material characterization instruments for use with its Zetasizer Nano particle characterization systems. The SV-10 is exceptionally easy to use and clean, is relatively low cost and gives rapid, highly accurate viscosity measurements in the range 0.3 to 10,000 mPa.s. With 1% accuracy across the whole measurement range, the data it generates can be used to enhance the accuracy of particle size measurements by dynamic light scattering. Used together, the SV-10 and the Zetasizer Nano provide an excellent option for the study of emulsions and dispersions, and more particularly for the characterization of proteins in solution prior to crystallization.
The technique of dynamic light scattering determines particle size by observing the random movement of particles undergoing Brownian motion. As this behaviour is directly related to the viscosity of the fluid in which the particles are moving, inaccuracies in the measurement of viscosity translate directly into inaccuracies in particle size measurement. The very high accuracy of the SV-10, even at the low viscosities typical of aqueous media, therefore makes it an invaluable accessory for dynamic light scattering systems.
The SV-10 determines viscosity by measuring the current required by an electromagnetic drive to vibrate two gold paddles immersed in the sample at constant amplitude. The damping effect on the vibration due to the sample is related to its viscosity. The system takes around 15 seconds to stabilize, after which a continuous reading of viscosity is produced. The use of gold plated sensors makes the unit compatible with all fluids and it is suitable for measurements in the temperature range 0 to 100oC. Further details at www.malvern.co.uk/viscometer