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Thermodynamics

Thermodynamics research at NIST helps our industrial and scientific partners develop more efficient and reliable processes by improving our understanding of how the arrangement of matter and energy impact the properties of physical and chemical systems.

Thermodynamic Data Included in Phase-Based Data Repository

MGI diagram

An essential part of the MGI is the development of phase-based data repository. Phase-based data are important for many applications, including the development of CALPHAD-based multicomponent databases. The phase-based data include zero-dimensional, one-dimensional, two-dimensional, and three-dimensional data. Examples of some of the phase-data included are phase transformation temperatures (e.g. melting, solidus, solvus), lattice parameters, thermal expansion, elastic constants, and diffusion coefficients and compositions profiles. These data are reported as functions of composition, temperature and/or pressure.

This repository consists of three data sources:

  • Curated experimental and computational multicomponent alloy data in support of the development Co-based superalloys. Currently the data are focus on diffusion data and transition temperatures. These data are curated using the NIST Materials Data Curation System. This collection is being developed in conjunction with CHiMaD.
  • Thermodynamic Research Center Data provides access to thermophysical property data with a focus on unary, binary, and ternary metal systems through a free online web application and associated API. All data are from original experimental publications and include full provenance and critically evaluated uncertainty.
  • Self diffusion and impurity diffusion coefficient data (experimental and computational) are searchable via the periodic table.

News and Updates

Projects and Programs

Gas properties for flow metering

Flow meters that rely on measuring the pressure drop across a laminar flow element can be accurately calibrated using a benign surrogate gas (such as helium or

Ceramic Phase Equilibrium Data

Advanced ceramics and inorganic materials are critically enabling elements in devices and systems across many technology sectors, such as telecommunications and

Publications

Tools and Instruments

Piston gauges and pressure transducers

Piston gauges are used to calibrate customer piston gauges and pressure sensing devices. Piston gauges are calibrated via a direct comparison to another piston

Low Pressure Gauges

NIST has developed best-in-the-world primary standard pressure measurement capabilities for pressures spanning the range of 0.01 Pa to 360 kPa through the

Vacuum Gauges

Most calibrations of vacuum gauges are based on a known gas flow rate that is generated by one of two flow meters that operate at constant pressure. The "piston

Leak Artifacts

Leak artifacts are calibrated in the range 1 x 10-6 to 1 x 10-13 mol/s (2 x 10-2 to 2 x 10-9 std. cm3/s at 0 °C). The calibration can be performed directly

Awards

Standard Reference Data

  • REFPROP - NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP): Version 9.1
    • New release expected October 2017 - Version 10. Purchase version 10 for $325.00 now! Receive version 9.1 now and version 10 when it is released.

Thermodynamics Research Center

The Thermodynamics Research Center (TRC) performs several functions related to providing state-of-the-art thermodynamic data:

  • Compiles and evaluates experimental data
  • Develops tools and standards for archival and dissemination of thermodynamic data, especially critically evaluated data
  • Develops electronic database products
  • Maintains a web-repository of published data in the THERMOML ARCHIVES, stored in THERMOML  — an XML format developed by TRC for the representation of thermodynamic data