Viscosity of Hydrogen, Deuterium, Methane, and Carbon Monoxide from —50° to 150°C below 200 Atmospheres

The absolute viscosities of H2, D2, CH4, and CO have been determined from measurements in a capillary-flow viscometer in the temperature range from —50° to 150°C and at pressures below 200 atm with an average precision of 0.1%. The accuracy of the measurements, with some exceptions, is estimated to be about 0.2%. Comparison of the H2 and D2 viscosities appears to confirm a difference between their intermolecular potentials.