Development Of A Vibrating-wire Viscosity Measurement System

Viscosity is one of the thermophysical properties of fluids and widely usedin the fields of energy, chemistry and so on. It is also the basis of scientific researchand engineering design. When compared with others methods for viscosity,vibrating-wire viscometer is simple, reliable and easily operated. So, it was chosen tomeasure the viscosity of fluids in this paper.A vibrating-wire viscometer was present in this paper. A tungsten wire of0.1mm diameter was used as the sensor. Two pieces of Sm2Co17magnets were usedto provide the magnetic field. The wire was clamped in both of the ends with twoclamps made of316stainless steel. A machineable ceramic tube was used as thesupport. The applicable range of the viscometer is from0to30MPa.A multilayersolid thermostatic bath was developed in this paper. In order to conduct heat quickly,it was made from Aluminum metal. The temperature fluctuation of the thermostatwas within±5mK for10hours. A measurement system was designed. A functiongenerator（Agilent33220a） and a lock-in amplifier(SR830) were used to as a sourceand a receiver of the signal, respectively. Both of them were connected with anindustrial computer using a GPIB cable.The parameters of the viscometer were obtained. The damping coefficient of thewire was measured in vacuum and the radius of the wire was obtained by using highpurity toluene as the sample fluid.In order to test the performance of this apparatus, the viscosity of toluene inliquid phase was measured at different temperatures from312.95K to332.76K andpressures from0.1MPa to20MPa. The experimental results were compared with thestandard reference data. The results show that the measured data agreed withstandard reference data within±1.85%.The relative expanded uncertainty of theexperimental results is within±2%.