Viscosity of deuterium oxide and water in the range 5 to 125 C

Measurements of the absolute viscosity of deuterium oxide of 99.5 percent purity and of water were made over the range 5 to 125 C. It is estimated that t hese determinations are accurate within 0.1 percent in relation to the value 1.0050 centipoise for the viscosity of water at 20 0 C. The work also included determinations of t he density of deuterium oxide over the range 90 to 125 0 C. Values for the viscosity and density of 100-percent deuterium oxide were obtained by linear extrapolations. The ratio of the viscosity of deuterium oxide to that of water at the same temperature was found to be 1.3052 at 5 C. This ratio decreased at a diminishing rate with increase in temperature to a value of 1.1456 at 125 C.