Validation of a Vibrating-Wire Viscometer: Measurements in the Range of 0.5 to 135 mPa·s

The present article describes a novel vibrating-wire viscometer that has been shown to be able to measure viscosities up to 135 mPa·s, after calibration against water at 20 °C, to provide direct traceability to the primary reference for viscosity. For the purpose of validating the instrument, measurements of the viscosity of some selected fluids, including standard reference liquids with viscosity on the order of 100 mPa·s at 20 °C and 2,2,4-trimethylpentane with a viscosity of about 0.5 mPa·s at the same temperature, were performed. The results obtained show that the instrument is capable of performing viscosity measurements with an estimated overall uncertainty better than ±0.8% over the range of (0.5 to 135) mPa·s.