Viscosity Measurements on Natural Gas: Re-evaluation

Previous experimental viscosity data for natural gas, published by Schley et al. (Int J Thermophys 25:1623, 2004) and originally obtained using a vibrating-wire viscometer in the temperature range between 260 K and 320 K, were re-evaluated after an improved re-calibration. For this purpose, a new reference value for the viscosity of argon at 298.15 K and at zero density, proposed by Vogel et al. (Mol Phys 108:3335, 2010) and further updated by Hellmann (Private communication, University of the Federal Armed Forces Hamburg, Hamburg, 2020), was applied. In addition, the density computed from the measured temperatures and pressures was determined using the equation of state by Kunz and Wagner (J Chem Eng Data 57:3032, 2012) instead of employing a calculation according to the International Standard ISO 12213 nowadays out of date.