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NATLINST.OFSTAND&TECHR.I.C. A11103 b^3M5M 2 o 260-117 NIST SPECIAL PUBLICATION c U.S. DEPARTMENT OF COMMERCE/Technology Administration/National Institute ofStandards and Technology Standard Reference Materials: Antireflecting-Chromium SRM Linewidth Standard, 475, for Calibration of Optical Microscope Linewidth Measuring Systems QC ol F. Vezzetti, Ruth N. Varner, and James E. Potzick 100 .U57 260-117 1992 NATIONAL u, TE OF STANDARDS 4b TECHNOLOGY Research Information Center MD Gaithersburg, 20899 DATE DUE Demco,Inc.36-233 NIST Special Publication 260-117 Standard Reference Materials: Antireflecting-Chromium SRM Linewidth Standard, 475, for Calibration of Optical Microscope Linewidth Measuring Systems Carol F. Vezzetti Ruth N. Varner James E. Potzick Precision Engineering Division Manufacturing Engineering Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899 U.S. DEPARTMENT OF COMMERCE, Robert A. Mosbacher, Secretary TECHNOLOGY ADMINISTRATION, Robert M. White, Under Secretary for Technology NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY, John W. Lyons, Director Issued January 1992 National Institute of Standards and Technology Special Publication 260-117 Natl. Inst. Stand. Technol. Spec. Publ. 260-117, 49 pages (Jan. 1992) CODEN: NSPUE2 U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1992 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402-9325 Preface Standard Reference Materials (SRM's) as defined by the National Institute of Standards and Technology (NIST) are well-characterized materials, produced in quantity and certified for one or more physical or chemical properties. They are used to assure the accuracy and compatibility of measurements throughout the Nation. SRM's are widely used as primary standards in many diverse fields in science, industry, and technology, both within the United States and throughout the world. They are also used extensively in the fields of environmental and clinical analysis. In many applications, traceability of quality control and measurement processes to the national measurement system is carried out through the mechanism and use of SRM's. For many of the Nation's scientists and technologists, it is therefore of more than passing interest to know the details of the measurements made at NIST in arriving at the certified values of the SRM's produced. The NIST Special Publication 260 Series is a series of papers reserved for this purpose. The 260 Series is dedicated to the dissemination of information on different phases of the preparation, measurement, certification, and use of NIST SRM's. In general, much more detail will be found in these papers than is generally allowed, or desirable, in scientific journal articles. This enables the user to assess the validity and accuracy of the measurement processes employed, to judge the statistical analysis, and to learn details of techniques and methods utilized for work entailing greatest care and accuracy. These papers also should provide sufficient additional information so SRM's can be utilized in new applications in diverse fields not foreseen at the time the SRM was originally issued. Inquiries concerning the technical content of this paper should be directed to the author(s). Other questions concerned with the availability, delivery, price, and so forth, will receive prompt attention from: Standard Reference Materials Program Bldg. 202, Rm. 204 National Institute of Standards and Technology Gaithersburg, MD 20899 William P. Reed, Chief Standard Reference Materials Program iii OTHERNIST PUBLICATIONSIN THISSERIES McKenzie, R. L., ed., NIST Standard Reference Mate- Napolitano,A.,andHawkins,E.G.,StandardReference rialsCatalog 1990-91,NISTSpec.Publ.260(January Materials: Viscosity ofStandard Lead-Silica Glass, 1990) NBS Misc. Publ. 260-11 (November 1966). Michaelis, R. E.,andWyman,L.L.,StandardReference Yakowitz, H., Vieth, D. L., and Michaelis, R. E., Stan- Materials: Preparation of White Cast Iron dard Reference Materials: Homogeneity Charac- Spectrochemical Standards, NBS Misc. Publ. 260-1 terizationofNBSSpectrometricStandardsIII: White (June 1964). COM74-11061** Cast Iron andStainless Steel PowderCompact, NBS Michaelis,R.E.,Wyman,L.L.,andFlitsch,R.,Standard Misc. Publ. 260-12(September 1966). Reference Materials: Preparation of NBS Copper- Menis,O.,andSterling,J.T., StandardReferenceMate- Base Spectrochemical Standards, NBS Misc. Publ. rials: Determination of Oxygen in Ferrous Mate- 260-2 (October 1964). COM74-11063** rials—SRM 1090, 1091, and 1092, NBS Misc. Publ. Michaelis,R. E., Yakowitz, H.,andMoore,G. A., Stan- 260-14(September 1966). dard Reference Materials: Metallographic Charac- Yakowitz, H., Michaelis, R. E., and Vieth, D. L., Stan- terization ofan NBS SpectrometricLow-Alloy Steel dard Reference Materials: Homogeneity Charac- Standard, NBS Misc. Publ. 260-3 (October 1964). terization of NBS Spectrometric Standards IV: COM74-11060** Preparation and Microprobe Characterization ofW- Alvarez, R., and Flitsch, R., Standard Reference Mate- 20% Mo Alloy Fabricated by Powder Metallurgical rials: Accuracy of Solution X-Ray Spectrometric Methods, NBS Spec. Publ. 260-16 (January 1969). Analysis of Copper-Base Alloys, NBS Misc. Publ. COM74-11062** 260-5 (March 1965). PB168068** Paule, R. C, and Mandel, J., StandardReferenceMate- Shultz, J. I., StandardReferenceMaterials: Methods for rials: Analysis of Interlaboratory Measurements on theChemicalAnalysisofWhiteCastIron Standards, theVaporPressureofGold(CertificationofStandard NBS Misc. Publ. 260-6 (July 1965). COM74- Reference Material 745). NBS Spec. Publ. 260-19 11068** (January 1970). PB190071** Bell, R. K., Standard Reference Materials: Methods for Paule, R. C, andMandel, J., StandardReference Mate- the Chemical Analysis of NBS Copper-Base rials: Analysis of Interlaboratory Measurements on Spectrochemical Standards, NBS Misc. Publ. 260-7 the Vapor Pressures of Cadmium and Silver, NBS (October 1965). COM74-11067** Spec.Publ.260-21 (January 1971).COM74-11359** Richmond, M. S., Standard Reference Materials: Yakowitz,H.,Fiori,C.E.,andMichaelis,R.E.,Standard Analysis of Uranium Concentrates at the National Reference Materials: Homogeneity Characterization Bureau of Standards, NBS Misc. Publ. 260-8 ofFe-3 Si Alloy, NBS Spec. Publ. 260-22 (February (December 1965).COM74-11066** 1971).COM74-11357** Anspach,S.C,Cavallo,L.M.,Garfinkel,S.B.,Hutchin- Napolitano, A.,andHawkins,E.G.,StandardReference son, J. M. R., and Smith, C. N., Standard Reference Materials:ViscosityofaStandardBorosilicateGlass, Materials: Half Lives of Materials Used in the NBS Spec. Publ. 260-23 (December 1970). COM71- Preparation of Standard Reference Materials of 00157** NineteenRadioactiveNuclidesIssuedbytheNational Sappenfield, K. M., Marinenko, G., and Hague, J. L., Bureau of Standards, NBS Misc. Publ. 260-9 StandardReferenceMaterials: ComparisonofRedox (November 1965). COM74-11065** Standards, NBS Spec. Publ. 260-24 (January 1972). Yakowitz, H., Vieth, D. L., Heinrich, K. F. J., and COM72-50058** Michaelis, R. E., Standard Reference Materials: Hicho, G. E., Yakowitz, H., Rasberry, S. D., and Homogeneity Characterization of NBS Michaelis, R. E., Standard Reference Materials: A SpectrometricStandardsII:CartridgeBrassandLow- Standard Reference Material Containing Nominally Alloy Steel, NBS Misc. Publ. 260-10 (December Four Percent Austenite, NBS Spec. Publ. 260-25 1965). COM74-11064** (February 1971). COM74-11356** iv Martin, J. F., Standard Reference Materials: National Clark, A. F., Denson, V. A., Hust, J. G., and Powell, R. BureauofStandards-US SteelCorporation JointPro- L., StandardReference Materials: The Eddy Current gram forDeterminingOxygen andNitrogen inSteel, Decay Method for Resistivity Characterization of NBS Spec. Publ. 260-26 (February 1971). PB High-Purity Metals, NBS Spec. Publ. 260-39 (May 81176620** 1972). COM72-50529** Garner, E. L.,Machlan, L. A., and Shields,W. R., Stan- McAdie, H. G., Gam, P. D., and Menis, O., Standard dardReferenceMaterials:UraniumIsotopicStandard Reference Materials: Selection ofThermal Analysis Reference Materials, NBS Spec. Publ. 260-27 (April TemperatureStandardsThroughaCooperativeStudy 1971). COM74-11358** (SRM 758, 759, 760), NBS Spec. Publ. 260-40 Heinrich,K.F. J.,Myklebust,R.L.,Rasberry,S.D.,and (August 1972)COM72-50776** Michaelis, R. E., Standard Reference Materials: Wagner, H. L.,andVerdier, P. H., eds., StandardRefer- Preparation and Evaluation of SRM's 481 and 482 ence Materials: The Characterization of Linear Gold-Silver and Gold-Copper Alloys for Polyethylene, SRM 1475, NBS Spec. Publ. 260-42 Microanalysis, NBS Spec. Publ. 260-28 (August (September 1972). COM72-50944** 1971).COM71-50365** Yakowitz, H, Ruff, A. W., and Michaelis, R. E., Stan- Geller, S. B., StandardReference Materials: Calibration dard Reference Materials: Preparation and of NBS Secondary Standard Magnetic Tape (Com- HomogeneityCharacterization ofan AusteniticIron- puter Amplitude Reference) Using the Reference Chromium-Nickel Alloy, NBS Spec. Publ. 260-43 Tape Amplitude Measurement "Process A-Model (November 1972). COM73-50760** 2," NBS Spec. Publ. 260-29 (June 1971). COM71- Schooley, J. F, Soulen, R. J., Jr., and Evans, G. A., Jr., 50282** StandardReferenceMaterials: PreparationandUseof Gorozhanina,R. S.,Freedman, A.Y.,andShaievitch,A. Superconductive Fixed Point Devices, SRM 767, B. (translated by M. C. Selby), Standard Reference NBS Spec. Publ. 260-44(December 1972). COM73- Materials: Standard Samples Issued in the USSR (A 50037** Translation from theRussian), NBSSpec. Publ. 260- Greifer, B., Maienthal, E. J.,Rains,T. C,andRasberry, 30(June 1971). COM71-50283** S.D.,StandardReferenceMaterials: PowderedLead- Hust,J. G.,andSparks,L.L.,StandardReferenceMate- Based Paint, SRM 1579, NBS Spec. Publ. 260-45 rials: ThermalConductivityofElectrolyticIronSRM (March 1973). COM73-50226** 734 from 4 to 300 K, NBS Spec. Publ. 260-31 Hust, J. G., and Giarratano, P. J., Standard Reference (November 1971). COM71-50563** Materials: Thermal Conductivity and Electrical Mavrodineanu,R.,andLazar,J.W.,StandardReference Resistivity StandardReference Materials: Austenitic Materials: Standard Quartz Cuvettes for High Ac- Stainless Steel, SRM's 735 and 798, from 4 to 1200 curacy Spectrophotometry, NBS Spec. Publ. 260-32 K, NBS Spec. Publ. 260^6 (March 1975). COM75- (December 1973). COM74-50018** 10339** Wagner, H. L., Standard Reference Materials: Com- Hust, J. G., Standard Reference Materials: Electrical parisonofOriginalandSupplementalSRM705,Nar- Resistivity ofElectrolytic Iron, SRM 797, and Aus- rowMolecularWeightDistributionPolystyrene,NBS tenitic Stainless Steel, SRM 798, from 5 to 280 K, Spec. Publ. 260-33 (May 1972). COM72-50526** NBS Spec. Publ. 260-47 (February 1974). COM74- Sparks,L.L.,andHust,J. G.,StandardReferenceMate- 50176** rials: Thermal Conductivity of Austenitic Stainless Mangum, B. W., and Wise, J. A., Standard Reference Steel, SRM 735 from 5 to 280 K, NBS Spec. Publ. Materials: Description and Use of Precision Ther- 260-35 (April 1972.)COM72-50368** mometers for the Clinical Laboratory, SRM 933 and Cali, J. P., Mandel, J., Moore, L. J., and Young, D. S., SRM 934, NBS Spec. Publ. 260^18 (May 1974). StandardReferenceMaterials: ARefereeMethodfor Supersededby NISTSpec. Publ. 260-113. the Determination ofCalcium in Serum NBS SRM Carpenter,B.S.,andReimer,G. M.,StandardReference 915, NBS Spec. Publ. 260-36 (May 1972). COM72- Materials: Calibrated Glass Standards for Fission 50527** Track Use, NBS Spec. Publ. 260-49 (November Shultz, J. I., Bell, R. K., Rains, T. C, and Menis, O., 1974).COM74-51185** Standard Reference Materials: Methods of Analysis of NBS Clay Standards, NBS Spec. Publ. 260-37 (June 1972). COM72-50692** v Hust, J. G., and Giarratano, P. J., Standard Reference Velapoldi, R. A., Paule, R. C, Schaffer, R„ Mandel, J., Materials: Thermal Conductivity and Electrical Machlan,L. A.,andGramlich,J.W.,StandardRefer- Resistivity Standard Reference Materials: Electro- ence Materials: A Reference Method for the Deter- lyticIron,SRM's734and797from4to 1000K,NBS mination of Potassium in Serum, NBS Spec. Publ. Spec. Publ. 260-50(June 1975). COM75-10698** 260-63 (May 1979). PB297207** Mavrodineanu, R., and Baldwin, J. R., Standard Refer- Velapoldi,R.A.,andMielenz,K.D.,StandardReference enceMaterials:GlassFiltersAsaStandardReference Materials: AFluorescenceStandardReferenceMate- Material for Spectrophotometry-Selection, Prepara- rialQuinineSulfateDihydrate(SRM936),NBSSpec. tion, Certification, Use-SRM 930 NBS Spec. Publ. Publ. 260-64(January 1980). PB80-132046** 260-51 (November 1975). COM75-10339** Marinenko, R. B., Heinrich, K. F. J., and Ruegg, F. C, Hust, J. G., and Giarratano, P. J., Standard Reference Standard Reference Materials: Micro-Homogeneity Materials: Thermal Conductivity and Electrical Studies ofNBS Standard Reference Materials, NBS Resistivity Standard Reference Materials 730 and ResearchMaterials,andOtherRelatedSamples,NBS 799, from 4 to 3000 K, NBS Spec. Publ. 260-52 Spec. Publ. 260-65 (September 1979). PB300461** (September 1975).COM75-11193** Venable,W. H., Jr., andEckerle, K. L., StandardRefer- Durst, R. A., Standard Reference Materials: Stan- ence Materials: Didymium Glass Filters for dardization of pH Measurements, NBS Spec. Publ. Calibrating the Wavelength Scale of Spectrophoto- 260-53 (February 1988, Revision ofDecember 1975 meters-SRM2009,2010,2013,and2014,NBSSpec. version). Publ. 260-66(October 1979). PB80-104961** Burke, R. W., and Mavrodineanu, R., Standard Refer- Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel, J., enceMaterials:CertificationandUseofAcidicPotas- Murphy, T. J., and Gramlich, J. W., Standard Refer- sium Dichromate Solutions as an Ultraviolet ence Materials: A Reference Method for the Deter- Absorbance Standard, NBS Spec. Publ. 260-54 mination of Chloride in Serum, NBS Spec. Publ. (August 1977). PB272168** 260-67 (November 1979). PB80-110117** Ditmars, D. A., Cezairliyan, A., Ishihara, S., and Mavrodineanu, R., and Baldwin, J. R., StandardRefer- Douglas,T.B.,StandardReferenceMaterials:Enthal- enceMaterials:Metal-On-QuartzFiltersasaStandard pyand HeatCapacity; Molybdenum SRM 781, from Reference Material for Spectrophotometry SRM 273 to 2800 K, NBS Spec. Publ. 260-55 (September 2031, NBS Spec. Publ. 260-68 (April 1980). PB80- 1977). PB272127** 197486** Powell, R. L., Sparks, L. L., and Hust, J. G., Standard Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel, J., Reference Materials: Standard Thermocouple Mate- Machlan, L. A., Garner, E. L., and Rains, T. C, rial, Pt-67: SRM 1967, NBS Spec. Publ. 260-56 Standard Reference Materials: A Reference Method (February 1978). PB277172** for the Determination of Lithium in Serum, NBS Barnes, J. D., and Martin, G. M., Standard Reference Spec. Publ. 260-69 (July 1980). PB80-209117** Materials: PolyesterFilm forOxygen GasTransmis- Marinenko, R. B„ Biancaniello, F., Boyer, P. A., Ruff, sionMeasurementsSRM 1470,NBSSpec.Publ.260- A.W.,andDeRobertis,L.,StandardReferenceMate- 58 (June 1979). PB297098** rials: Preparation and Characterization of an Iron- Velapoldi, R. A., Paule, R. C, Schaffer, R., Mandel, J., Chromium-Nickel Alloy for Microanalysis, NBS and Moody, J. R., Standard Reference Materials: A Spec. Publ. 260-70(May 1981). PB84-165349** Reference Method for the Determination ofSodium Seward, R. W., and Mavrodineanu, R., Standard Refer- in Serum, NBS Spec. Publ. 260-60 (August 1978). ence Materials: Summary ofthe Clinical Laboratory PB286944** Standards Issued by the National Bureau of Stan- Verdier, P H., and Wagner, H. L., Standard Reference dards, NBS Spec. Publ. 260-71 (November 1981). Materials: The Characterization of Linear PB82-135161** Polyethylene (SRM 1482, 1483, 1484), NBS Spec. Reeder, D. J., Coxon, B., Enagonio, D., Christensen,R. Publ. 260-61 (December 1978). PB289899** G., Schaffer, R., Howell, B. F., Paule, R. C, and Soulen, R. J., and Dove, R. B., Standard Reference Mandel, J., Standard Reference Materials: SRM900, Materials: Temperature Reference Standard for Use Antiepilepsy DrugLevelAssayStandard,NBSSpec. Below 0.5 K (SRM 768), NBS Spec. Publ. 260-62 Publ. 260-72 (June 1981). PB81-220758 (April 1979). PB294245** vi Interrante, C. G., andHicho, G. E., Standard Reference Bowers,G. N.,Jr., Alvarez,R.,Cali,J. P.,Eberhardt, K. A Materials: StandardReferenceMaterialContaining R., Reeder, D. J., Schaffer, R., and Uriano, G. A., Nominally Fifteen Percent Austenite (SRM 486), Standard Reference Materials: The Measurement of NBS Spec. Publ. 260-73 (January 1982). PB82- the Catalytic (Activity) Concentration of Seven En- 215559** zymes in NBS Human Serum SRM 909, NBS Spec. Marinenko, R. B., Standard Reference Materials: Publ. 260-83 (June 1983). PB83-239509** PreparationandCharacterizationofK-411 andK-414 Gills,T. E., Seward, R. W., Collins,R. J., andWebster, Mineral Glasses for Microanalysis: SRM 470, NBS W.C,StandardReferenceMaterials: Sampling, Ma- Spec. Publ. 260-74(April 1982). PB82-221300** terials Handling, Processing, and Packaging ofNBS Weidner, V. R., and Hsia, J. J., Standard Reference Sulfur in Coal Standard Reference Materials 2682, Materials: Preparation and Calibration ofFirst Sur- 2683, 2684, and 2685, NBS Spec. Publ. 260-84 face Aluminum Mirror Specular Reflectance Stan- (August 1983). PB84-109552** dards (SRM 2003a), NBS Spec. Publ. 260-75 (May Swyt, D. A., Standard Reference Materials: A Look at 1982). PB82-221367** Techniques forthe DimensionalCalibration ofStan- Hicho, G. E., and Eaton, E. E., Standard Reference dard Microscopic Particles, NBS Spec. Publ. 260-85 Materials: AStandardReferenceMaterialContaining (September 1983). PB84-112648** NominallyFivePercentAustenite(SRM485a), NBS Hicho, G. E., and Eaton, E. E., Standard Reference Spec. Publ. 260-76(August 1982). PB83-115568** Materials: AStandardReferenceMaterialContaining Furukawa,G.T.,Riddle,J.L.,Bigge,W.G.,andPfieffer, TwoandOne-HalfPercentAustenite,SRM488,NBS E. R., Standard Reference Materials: Application of Spec. Publ. 260-86 (December 1983). PB84- Some Metal SRM's as Thermometric Fixed Points, 143296** NBS Spec. Publ. 260-77 (August 1982). PB83- Mangum, B. W., Standard Reference Materials: SRM 117325** 1969:RubidiumTriple-Point- ATemperatureRefer- Hicho, G. E., and Eaton, E. E., Standard Reference ence Standard Near 39.30 °C, NBS Spec. Publ. 260- Materials: Standard Reference Material Containing 87 (December 1983). PB84-149996** NominallyThirtyPercentAustenite(SRM487),NBS Gladney, E. S.,Burns,C.E.,Perrin, D.R.,Roelandts,I., Spec. Publ. 260-78 (September 1982). PB83- and Gills, T. E., Standard Reference Materials: 1982 115576** Compilation of Elemental Concentration Data for Richmond,J.C,Hsia,J.J.,Weidner,V.R.,andWilmer- NBS Biological, Geological, and Environmental ing, D. B., Standard Reference Materials: Second StandardReference Materials, NBS Spec. Publ. 260- SurfaceMirrorStandardsofSpecularSpectralReflec- 88 (March 1984). PB84-218338** tance (SRM's 2023, 2024, 2025), NBS Spec. Publ. Hust, J. G., Standard Reference Materials: A Fine- 260-79 (October 1982). PB84-203447** Grained, Isotropic Graphite for Use as NBS Ther- Schaffer, R., Mandel, J., Sun, T., Cohen, A., and Hertz, mophysical Property RM's from 5 to 2500 K, NBS H.S.,StandardReferenceMaterials:Evaluationbyan Spec. Publ. 260-89 (September 1984). PB85- ID/MS Method ofthe AACC Reference Method for 112886** Serum Glucose, NBS Spec. Publ. 260-80 (October Hust, J. G., and Lankford, A. B., Standard Reference 1982) PB84-216894** Materials: Update of Thermal Conductivity and . Burke, R. W., and Mavrodineanu, R., Standard Refer- Electrical Resistivity ofElectrolytic Iron, Tungsten, ence Materials: Accuracy in Analytical andStainlessSteel,NBSSpec.Publ.260-90(Septem- Spectrophotometry, NBS Spec. Publ. 260-81 (April ber 1984). PB85-115814** 1983). PB83-214536** Goodrich, L. F., Vecchia, D. F., Pittman, E. S., Ekin, J. Weidner, V. R., Standard Reference Materials: White W., and Clark, A. F, Standard Reference Materials: Opal Glass Diffuse Spectral Reflectance Standards CriticalCurrentMeasurementsonanNbTiSupercon- for the Visible Spectrum (SRM's 2015 and 2016), ducting Wire Standard Reference Material, NBS NBS Spec. Publ. 260-82 (April 1983). PB83- Spec. Publ. 260-91 (September 1984). PB85- 220723** 118594** Carpenter, B. S., Standard Reference Materials: Calibrated Glass Standards for Fission Track Use (SupplementtoNBSSpec. Publ. 260-49), NBSSpec. Publ. 260-92(September 1984). PB85-113025** vis Ehrstein, J.R., Standard Reference Materials: Prepara- Weidner, V. R., Mavrodineanu, R., Mielenz, K. D., tion and Certification of Standard Reference Mate- Velapoldi, R. A., Eckerle, K. L., and Adams, B., rials forCalibration ofSpreading Resistance Probes, StandardReferenceMaterials: HolmiumOxideSolu- NBS Spec. Publ. 260-93 (January 1985). PB85- tionWavelengthStandardfrom240to640nm-SRM 177921** 2034, NBS Spec. Publ. 260-102 (July 1986). PB86- Gills, T. E., Koch, W. F., Stolz, J. W., Kelly, W. R., 245727** Paulsen,P.J.,Colbert,J.C,Kirklin,D.R.,Pei,P.T.S., Hust, J. G., Standard Reference Materials: Glass Weeks, S., Lindstrom, R. M., Fleming, R. F.,Green- Fiberblanket SRM for Thermal Resistance, NBS berg, R. R., and Paule, R. C, Standard Reference Spec. Publ. 260-103 (September 1985). SN003-003- Materials: Methods and Procedures Used at the Na- 02687-5* tional Bureau ofStandards to Certify Sulfur in Coal Mavrodineanu,R., and Alvarez,R., StandardReference SRM'sforSulfurContent,CalorificValue, AshCon- Materials: Summary ofthe Biological and Botanical tent, NBS Spec. Publ. 260-94 (December 1984). Standards Issued by the National Bureau of Stan- PB85-165900** dards, NBS Spec. Publ. 260-104 (November 1985). Mulholland, G. W., Hartman, A. W., Hembree, G. G., SN003-003-02704-9* Marx, E., and Lettieri, T. R., Standard Reference Mavrodineanu, R.,andRasberry, S. D., StandardRefer- Materials: Developmentofa 1 |im DiameterParticle ence Materials: Summary of the Environmental Re- Size Standard, SRM 1690, NBS Spec. Publ. 260-95 search,Analysis,andControlStandardsIssuedbythe (May 1985). SN003-003-02665-4* National Bureau ofStandards, NBS Spec. Publ. 260- Carpenter, B. S., Gramlich, J. W., Greenberg, R. R., 105 (March 1986). SN003-003-02725-1* Machlan, L. A., DeBievre, P., Eschbach, H. L., Koch,W.F.,ed.,StandardReferenceMaterials:Methods Meyer, H., Van Audenhove, J., Connolly, V. E., and Procedures Usedatthe National Bureau ofStan- Trahey, N. M., andZook, A. C, Standard Reference dards to Prepare, Analyze, and Certify SRM 2694, Materials: Uranium-235 Isotopic Abundance Stan- SimulatedRainwater,andRecommendationsforUse, dard Reference Materials for Gamma Spectrometry NBS Spec. Publ. 260-106 (July 1986). PB86- Measurements, NBS Spec. Publ. 260-96 (September 247483** 1986). PB87-108544** Hartman, A. W., and McKenzie, R. L., StandardRefer- Mavrodineanu, R., and Gills, T. E., Standard Reference enceMaterials:SRM 1965,MicrosphereSlide(10|im Materials: SummaryoftheCoal,Ore,Mineral,Rock, Polystyrene Spheres), NBS Spec. Publ. 260-107 and Refactory Standards Issued by the National (November 1988). Bureau ofStandards, NBS Spec. Publ. 260-97 (Sep- Mavrodineanu, R., andGills, T. E., StandardReference tember 1985). SN003-003-02688-3* Materials: SummaryofGasCylinderandPermeation Hust, J. G, Standard Reference Materials: Glass Fiber- Tube Standard Reference Materials Issued by the boardSRM forThermalResistance, NBSSpec. Publ. National Bureau ofStandards, NBS Spec. Publ. 260- 260-98 (August 1985). SN003-003-02674-3* 108 (May 1987). Callanan, J. E., Sullivan, S. A., and Vecchia, D. F., Candela,G. A.,Chandler-Horowitz,D., Novotny, D. B., Standard Reference Materials: Feasibility Study for Marchiando, J. F., and Belzer, B. J., StandardRefer- the Development of Standards Using Differential ence Materials: Preparation and Certification of an Scanning Calorimetry, NBS Spec. Publ. 260-99 Ellipsometrically Derived Thickness and Refractive (August 1985). SN003-003-02675-1* Index Standard of a Silicon Dioxide Film (SRM Taylor, J. K., Standard Reference Materials: Handbook 2530), NISTSpec. Publ. 260-109 (October 1988). forSRMUsers,NBSSpec.Publ.260-100(September Kirby, R. K, and Kanare, H. M., Standard Reference 1985). PB86-110897** Materials: PorUand Cement Chemical Composition Mangum, B. W., Standard Reference Materials: SRM Standards (Blending, Packaging, and Testing), NBS 1970, Succinonitrile Triple-Point Standard: A Spec. Publ. 260-110(February 1988). TemperatureReferenceStandardNear58.08°C,NBS Gladney,E. S.,O'Malley,B.T.,Roelandts, L,andGills, Spec. Publ. 260-101 (March 1986). SN003-003- T. E., Standard Reference Materials: Compilation of 02722-7* Elemental Concentration Data for NBS Clinical, Biological, Geological, and Environmental Standard Reference Materials, NBS Spec. Publ. 260-111 (November 1987). viii