This web application provides free and open access for the broader research community to the experimental planning utilities that are incorporated into ThermoData Engine (TDE) [J. Chem. Inf. Model. 2005, 45, 816-838]. TDE provides recommendations for the relative merit of a proposed 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 parameters for deployment of prediction methods. The web applications provides 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 model. The primary focus of this recommendation service is molecular organic compounds. Some common inorganic and organometallic compounds are included, but, in general, polymers, radicals, ions, salt and acid solutions, metals, metal oxides, and inter-metallics are not considered. References NIST Standard Reference Data 103a and 103b.

The ThermoData Engine fully implements all major principles of the concept of dynamic data evaluation formulated at NIST?s Thermodynamics Research Center (TRC). Dynamic data evaluation relies on large electronic databases to store the currently known experimental data along with detailed descriptions of relevant metadata and uncertainties. Combining this data with expert software allows the ThermoData Engine to producing data compilations 'to order' which include all major thermophysical properties (such as density, vapor pressure, heat capacity, enthalpies of phase transitions, critical properties, melting and boiling points, etc). As the name of this resource implies, its scope is pure compounds, binary mixtures and reactions. If you are only interested in pure compounds please see NIST ThermoData Engine - Pure Compounds - SRD 103a (https://www.nist.gov/srd/nist-standard-reference-database-103a).

ThermoML is an XML-based IUPAC standard for the storage and exchange of experimental thermophysical and thermochemical property data. The ThermoML archive is a subset of Thermodynamics Research Center (TRC) data holdings corresponding to cooperation between NIST TRC and five journals: Journal of Chemical Engineering and Data (ISSN: 1520-5134), The Journal of Chemical Thermodynamics (ISSN: 1096-3626), Fluid Phase Equilibria (ISSN: 0378-3812), Thermochimica Acta (ISSN: 0040-6031), and International Journal of Thermophysics (ISSN: 1572-9567). Data from initial cooperation (around 2003) through the 2019 calendar year are included. The original scope of the archive has been expanded to include JSON files. The JSON files are structured according to the ThermoML.xsd (available below) and rendered from the same experimental thermophysical and thermochemical property data reported in the corresponding articles as the ThermoML files. In fact, the ThermoML files are generated from the JSON files to keep the information in sync. The JSON files may contain additional information not supported by the ThermoML schema. For example, each JSON file contains the md5 checksum on the ThermoML file (THERMOML_MD5_CHECKSUM) that may be used to validate the ThermoML download. This data.nist.gov resource provides a .tgz file download containing the JSON and ThermoML files for each version of the archive. Data from initial cooperation (around 2003) through the 2019 calendar year are provided below (ThermoML.v2020-09.30.tgz). The date of the extraction from TRC databases, as specified in the dateCit field of the xml files, are 2020-09-29 and 2020-09-30. The .tgz file contains a directory tree that maps to the DOI prefix/suffix of the entries; e.g. unzipping the .tgz file creates a directory for each of the prefixes ( 10.1007, 10.1016, and 10.1021) that contains all the .json and .xml files. The data and other information throughout this digital resource (including the website, API, JSON, and ThermoML files) have been carefully extracted from the original articles by NIST/TRC personnel. Neither the Journal publisher, nor its editors, nor NIST/TRC warrant or represent, expressly or implied, the correctness or accuracy of the content of information contained throughout this digital resource, nor its fitness for any use or for any purpose, nor can they, or will they, accept any liability or responsibility whatever for the consequences of its use or misuse by anyone. In any individual case of application, the respective user must check the correctness by consulting other relevant sources of information.

The Web Thermo Tables (WTT) are a collection of critically evaluated thermodynamic property data for pure compounds with a primary focus on organics. These data were generated through dynamic data analysis, as implemented in the NIST ThermoData Engine software package. Also included are some critically evaluated data from the historical TRC Thermodynamic Tables archive. The Professional Edition contains information on over 28,000 compounds. For a subset of the data focused on commonly-used pure compounds please see the Lite Edition (http://www.nist.gov/srd/nistwebsub2.cfm) .

The National Institute of Standards and Technology (NIST) maintains the United States' primary standards for traceable RF and mm-wave power measurements. In the 2.4 mm connector type, the specialized sensors that NIST currently uses as primary standards are not commercially available, which raises concerns about the long-term sustainability of NIST's measurement capabilities. These concerns motivated us to explore the option of using commercially available thermoelectric power sensors. In this paper, we describe a power metering procedure and a preliminary uncertainty analysis for a power sensor that could be used for traceable RF power measurements. With our metering procedure we see good metered power linearity up to about 17 mW of RF power, weak temperature dependence, and an overall fractional measurement uncertainty of about 0.10\% (k = 1).

REFPROP is an acronym for REFerence fluid PROPerties. This program, developed by the National Institute of Standards and Technology (NIST), calculates the thermodynamic and transport properties of industrially important fluids and their mixtures. These properties can be displayed in Tables and Plots through the graphical user interface; they are also accessible through spreadsheets or user-written applications accessing the REFPROP dll. REFPROP is based on the most accurate pure fluid and mixture models currently available. It implements three models for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modified Benedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model. Mixture calculations employ a model that applies mixing rules to the Helmholtz energy of the mixture components; it uses a departure function to account for the departure from ideal mixing. Viscosity and thermal conductivity are modeled with either fluid-specific correlations, an ECS method, or in some cases the friction theory method.

Special Database 19 contains NIST's entire corpus of training materials for handprinted document and character recognition. It publishes Handprinted Sample Forms from 3600 writers, 810,000 character images isolated from their forms, ground truth classifications for those images, reference forms for further data collection, and software utilities for image management and handling. there are two editions of the databases. One is the original database with the images in mis or pct format. It also includes software to open and manipulate the data. The second edition has the images all in PNG format.