PREFACE Within the framework of the NBS Institute for Materials Research the area of standard reference materials is a broad and important one, including the preparation, characterization and distribution of a wide variety of materials in such diverse fields as metallurgy, polymers and inorganic materials. In carrying out such a program there is much interaction with representatives of industry and science, beginning with discussions as to which primary standard materials will do most to advance technology, the furnishing of materials and fabrication of samples, and the characterization and certification of the materials by cooperative efforts. The many groups participating in a standards program are very interested in detailed information on specific aspects of the program but to date there has been no publication outlet for such written discussions. To meet this need, NBS Miscellaneous Publication 260 has been reserved for a series of papers in the general area of "standard reference materials". This series will present the results of studies and investigations undertaken within the Institute for Materials Research with emphasis on the preparation and characterization of standard reference materials. This subject-oriented series will provide a means for rapid dissemination of this detailed information and we hope will stimulate the use of standard reference materials in science and industry. OTHER NBS PUBLICATIONS OF INTEREST NBS Miscellaneous Publication 260-1, Preparation of NBS White Cast Iron Spectrochemical Standards, June 1964. 30 cents. NBS Miscellaneous Publication 241, Standard Materials Issued by the National Bureau of Standards: A Descriptive List with Prices, March 1962. 30 cents. Up-to-date supplementary insert sheets to Misc. Publ. 241 list new, renewal, out of stock, and discontinued standards. This sheet is available without charge directly from the National Bureau of Standards, Washington, D.C., 20234. NBS Miscellaneous Publication 250, Calibration and Test Services of the National Bureau of Standards, November 1963. 70 cents. Send orders with remittance to: Superintendent of Documents, U. S. Government Printing Office, Washington, D.C., 20402. Remittances from foreign countries should include an additional one-fourth of the purchase price for postage. LIST OF FIGURES FIGURE No. PAGE 1. Tapping the molten metal from the furnace 12 2. Pouring of test samples prior to pouring 13 3. Solidified casting on the water-cooled 14 4. 5. 8. 9. 7. Analytical curve for zinc by x-ray analysis. 6. Sampling of disk for homogeneity testing Analytical curve for nickel by x-ray analysis, 31 Analytical curve for nickel by x-ray analysis, 32 10. Analytical curve for zinc by optical emission 32 11. Analytical curve for nickel by optical emission 34 12. Analytical curve for nickel by optical emission |