IUPAC SUBCOMMITTEE ON TRANSPORT PROPERTIES MEETING AT NIST (BOULDER).

The Subcommittee on Transport Properties of the International Union of Pure and Applied Chemistry (IUPAC) held its annual meeting in June 2000, at NIST (Boulder, CO).

Several standard reference projects were declared completed during the subsequent business session of the meeting with publications to follow soon. Toluene will be the first liquid reference material for viscometer calibrations both at atmospheric as well as at elevated pressure. An improved correlation of the viscosity of isobutane has been published. A standard reference correlation for the viscosity of saturated liquid n pentane will make it possible to use this fluid for calibrations of sealed gravitational capillary viscometers.

A broad discussion was devoted to the possible revision of the standard reference value for the viscosity of liquid water at 20 [degrees]c and atmospheric pressure. NIST researchers were asked to investigate the records at NIST about the crucial measurements which were published in 1952. Liquids suitable to establish a second viscosity standard at 1 Pa s were discussed. It was agreed that hygroscopic compounds such as alcohols do not possess the required composition stability. The suggestion was made to "design" a fluid with the desired properties for a standard reference material.

The next meeting of the subcommittee is scheduled for September 2001, near Thessaloniki, Greece.