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This freely available tool ( was developed at the Thermodynamics Research Center (TRC) of the MML Thermophysical Properties Division to aid in the process of experimental planning for thermophysical property measurements and is intended for a global community of experimentalists. ThermoPlan provides recommendations for the relative merit of a given measurement via assessment of the existing body of knowledge, including availability of experimental thermophysical property data, variable ranges studied, associated uncertainties, state of prediction methods, and availability of parameters for deployment of prediction methods. This Web application supports utilities for the assessment of specific property measurements for pure and binary chemical systems, the broader data needs of pure systems, and recommendations for binary mixture measurements that could extend the current UNIFAC prediction model.

The algorithmic approach to experiment planning implemented in ThermoPlan is based on technology previously developed at TRC for NIST ThermoData Engine (TDE, Standard ReferenceDatabases 103a and 103b). ThermoPlan is designed and developed, in part, to respond to the increasing need of the scientific and engineering communities for experiment planning in the field of thermophysical property measurement science. It is aimed at increasing the focus of the international thermophysical properties community on measurements, which will make an impact.


  • Aid in determination of redundant or irrelevant measurement problems
    • Inputs:  chemical/components in system, temperature/pressure range, property measurand, uncertainty of measurement
    • Output: value of potential measurement, similar measurement published.
  • The combination of these electronic databases with expert-system software, designed to automatically generate recommended property values based on available experimental and predicted data, leads to the ability to produce critically evaluated data dynamically or "to order."


  • Pure organic compounds
  • Binary mixture systems containing organic compounds
  • Ternary mixture systems containing organic compounds
  • Thermodynamic properties
  • Thermochemical properties
  • Transport properties





      There is no cost  to access the ThermoPlan database

      ThermoPlan is distributed by Standard Reference Data Program,

      National Institute of Standards and Technology, Gaithersburg, MD 20899.





      NIST ThermoPlan Database Citation Examples


      Data provided via the NIST ThermoPlan (SRD#167) +[version] was used.

      In a list of References:

      1. Kroenlein, K.; Diky, V.; Muzny, C.D.; Chirico, R.D.; Magee, J.W.; Frenkel, M. "NIST Standard Reference Database 167: ThermoPlan Experimental Planning and coverage evaluation aid for thermophysical property measurements" Version , National Institute of Standards and Technology, Gaithersburg, MD , 20899, , (accessed #date).

      DISCLAIMER: The National Institute of Standards and Technology (NIST) uses its best effort to deliver a high-quality interface and access to the underlying database, and to verify that the methods and data contained therein are broadly comprehensive and have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in this information resource. This resource is designed to be a software aid for planning new experimental measurements of thermophysical properties, but in no way substitutes for intensive literature review, relevant data analysis, and judgements based on specific needs.


      Created February 8, 2017, Updated November 15, 2019