This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of silicon. A unit of SRM 3150 consists of 50 mL of solution prepared gravimetrically to contain a known mass fraction of silicon in a high-density polyethylene bottle sealed in an aluminized bag. The solution is prepared gravimetrically from sodium metasilicate nonahydrate to contain a known mass fraction of silicon in water. This data is public in the Certificate of Analysis for this material.

NIST has accumulated a valuable and comprehensive collection of thermal conductivity data from measurements performed with a 200-mm square guarded-hot-plate apparatus. The guarded-hot-plate test method is arguably the most accurate and popular method for determination of thermal transmission properties of flat, homogeneous specimens under steady state conditions. Several organizations, including ASTM and ISO, have standardized the method. Version 1.0 of the database includes data for over 2000 measurements, covering several categories of materials including concrete, fiberboard, plastics, thermal insulation, and rubber. The data cover a temperature range corresponding to most building applications; however, the majority of the measurements were conducted at 24° C (75° F). Web version 1.0

This Standard Reference Material (SRM) is intended primarily for use in the evaluation of techniques used in the analysis of coals and materials of a similar matrix. A unit of SRM 2685c consists of 50 g of bituminous coal ground to pass a 250 ?m (60 mesh) sieve, homogenized, and packaged in an amber glass bottle under an argon atmosphere, and sealed in an aluminized bag.

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of samarium. A unit of SRM 3147a consists of five 10 mL sealed borosilicate glass ampoules of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of samarium. The solution contains nitric acid at a volume fraction of approximately 10 %, which is equivalent to a concentration (molarity) of approximately 1.6 mol/L. This data is public in the Certificate of Analysis for this material.

A collaborative study to compare the long-term measurement performance between guarded-hot-plate facilities at the Laboratoire national de métrologie et d'essais (LNE) in France and the National Institute of Standards and Technology (NIST) in the United States is presented. Thermal conductivity data were compiled from three international comparisons organized from 1997 to 2014. Measurements were conducted in accordance with standardized test methods (ISO 8302 or ASTM C 177) over a temperature range from 280 K to 320 K. Nine thermal insulating materials (either mineral fiber or expanded polystyrene) were examined covering broad ranges of bulk densities (13 kg/m3 to 200 kg/m3) and thicknesses (13 mm to 70 mm). A different set of specimens was utilized for each comparison. Results of this study indicate that, over a 17 year interval, the majority of test data from LNE and NIST agreed to within ±1.0%, or less, for mineral fiber materials and to within ±0.5%, or less, for expanded polystyrene. The long-term variability limit of 1% between the two laboratories is in good agreement with their current measurement uncertainties. Regression coefficients and their standard uncertainties for a straight-line model relating thermal conductivity to temperature from 280 K to 320 K were computed by material and laboratory. Graphical analysis of the data and corresponding fits exhibit consistent behavior by material type between the two laboratories. Sources of measurement variability are addressed. See also related: "Data from: Collaborative Guarded-Hot-Plate Tests between the National Institute of Standards and Technology and the National Physical Laboratory," accessible at https://doi.org/10.18434/M32106

This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of tungsten. A unit of SRM 3163 consists of 50 mL of an acidified aqueous solution prepared gravimetrically to contain a known mass fraction of tungsten in a high-density polyethylene bottle sealed in an aluminized bag. The solution contains nitric acid at a volume fraction of approximately 7 % and hydrofluoric acid at a volume fraction of approximately 4 %, equivalent to amount of substance concentrations (molarities) of approximately 1.2 mol/L and 1.1 mol/L respectively. This data is public in the Certificate of Analysis for this material.

SRM 2452 Hydrogen in Titanium (Nominal Mass Fraction 60 mg/kg) - This Standard Reference Material (SRM) is intended for use in the evaluation of methods and the calibration of equipment used in the determination of hydrogen in titanium alloy. SRM 2452 consists of one bottle containing 10 g of titanium alloy chips. This data is public in the Certificate of Analysis for this material.