Comparability of measurements and traceability to national standards is a critical element in the modern chemicals and materials manufacturing enterprise – now almost universally global in character. Comparability and traceability is vital not only to commodity exchange – for example in natural gas or hydrogen rich fuels – but also for transportability and interoperability of manufacturing hardware systems – realizations of the unit operations of the production systems. The system of measurement supporting these needs is supported by the activities under this project. Standards for fluid density and viscosity (bulk) as functions of composition, temperature and pressure and measurement standards associated with absolute and differential calorimetry are familiar elements of this infrastructure. International agreements on equations of state of vital commodities also are enabled by this work. Current and future tasks within this project include: development of a liquid density standard covering large ranges of operating temperatures, measurements of properties for extremely small quantities of material (important for exceptionally high value chemicals), property measurements on chemically unstable systems, and on ionic liquids. The tasks included in this project are: “Property Standards” and “Apparatus Development”

• Precision Densimetry for Primary Temperature Metrology: This research has included numerical studies to determine the optimum working gas and the measurement uncertainties needed to obtain a thermometer with an uncertainty of a few thousanths of a kelvin.. This work is enabled by a new apparatus recently put into operation in the Division which is proving to be more accurate than older methods by factor of ten.
• Reference Equations of State: The REFPROP database has been the de facto standard in the refrigeration industry for many years. In 2004, a new ISO standard for refrigerant properties was approved which adopts the same formulations as those used in REFPROP, making REFPROP the foundation for and compliant with the international standard. CSTL researchers were key members of the working group which developed this standard.