Viscosity of Argon—Ammonia Mixtures

The paper reports a series of measurements of the viscosity of argon—ammonia mixtures at 20° and 30°C over a pressure range from atmospheric to 25 atm. The method used was an absolute one, based on the oscillating-disk principle. The precision of the measurement varied from 0.2% for argon-rich to 1.5% for ammonia-rich mixtures, the largest source of error being that of the determination of composition. In spite of the fact that one component is polar, the viscosity defect is small, the mixture behaving nearly perfectly with respect to viscosity. However, the density effect on the viscosity of ammonia and ammonia-rich mixtures has turned out to be negative.