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Alcan CRMs
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Inter-Laboratory Analysis ProgramProgram Protocol ScopeThe purpose and scope of this specification is to define certain terminology, procedural techniques, criteria and protocol to be utilized by members of the ongoing "Inter-laboratory Analysis Program" (ILAP) conducted by Analytical Reference Materials International as it applies to the development, certification and production of certified reference materials. DefinitionsThe International Standards Organization (ISO) definitions, expressed in ISO Guide 301992 Second Edition list the following: Certifying Body - A technically competent body (organization or firm, public or private) that issues a Reference Material Certificate which provides the information detailed in ISO Guide 31. Reference Material (RM) - Material or substance with one or more properties of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to materials. Certified Reference Material (CRM) - Reference material, accompanied by a certificate, one or more of whose properties values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence. Inter-Laboratory Analysis ProgramASTM Standard E691-87 applies to Inter-laboratory studies to "Determine the Precision of a Single Test Method". This standard is also a well thought out and logical plan for conducting an Inter-laboratory program involving multiple techniques. Therefore, the planning, conducting, analyzing, protocol and treatment of data resulting from the ARMI\ILAP is performed utilizing the guidelines established in ASTM E691-87 where applicable. Selection of Participating LaboratoriesILAP membership is voluntary and consists of approximately 60% actual producers of the materials being analyzed, 30% technically qualified commercial laboratories and 10% representing general industry and academia. Source MaterialsMaterials are typically selected from standard industry stocks so as to emulate material types found in the real life circumstances dealt with by users in their daily analytical endeavors. Whenever possible, program materials are secured in a wrought condition. Other methods of manufacture such as continuous cast, sand or static castings are utilized as a last resort and only in the case of those materials being unavailable in wrought condition. Batch DeterminationSince most metals are available in bar stock or rod form, a typical "batch" or "series" is defined as a single length of material or a single bar of one continuous length. Sampling ProcedureThe "batch" samples are taken by dividing the bar into a minimum of twelve sub-sections. A one inch solid test sample is removed from each sub-section. Each one inch test sample is further subdivided as follows: The "batch" samples are taken by dividing the bar into a minimum of twelve sub-sections. A one inch solid test sample is removed from each sub-section. Each one inch test sample is further subdivided as follows:
Each member of the "Inter-laboratory Analysis Program" receives the three sample types and is therefore responsible for a specific sub-section of the batch bar. All sub-sections and corresponding test samples are sequentially marked with matching and unique internal identification numbers so that if abnormalities occur during the ILAP process, each test sample can be traced to the original sub-section. Due to this extensive sampling procedure, homogeneity of the total batch is therefore reflected as a product of the overall statistics and the resulting certified data. Specific Within Sample Determination of HomogeneityEffective with materials certified after 10/20/91, specific homogeneity testing is determined by the ILAP program management, and incorporates homogeneity test procedures as outlined in ASTM E-826-87, NBS Handbook 91, "Experimental Statistics", as well as other established practices for determination of practical homogeneity. Methods of AnalysisThe ARMI "Inter-laboratory Analysis Program" encompasses an extremely wide variety of materials. No single method would provide optimum data results. Therefore, the methods utilized are a combination of methods for classical wet chemistry, ICP, AA, Optical Emission and X-Ray spectrometric methods in addition to combustion procedures for the determinations of Carbon, Sulfur, Nitrogen and Oxygen. Extent of Data ReportedIt is the policy of Analytical Reference Materials International to report data submitted by two or more labs. However, in accordance with the guidelines established by the ILAP membership protocol, final certification occurs only for those elements in which a minimum of six data points remain after final critique. Therefore, data in parentheses ( ) is not certified but provided for information only. Certified Data that was selected by the ILAP membership for additional testing is indicated by brackets [ ]. TraceabilityTraceability to NIST is approached in two distinct ways within the ARMI\ILAP.
The analytical data results for the IARMs developed under this program are therefore "Traceable" to the U.S. Department of Commerce, National Institute of Standards & Technology, (NIST). The specific SRMs applicable to a certification are referenced on the face of the "Certificate of Analyses" for all ILAP certified materials. |
PT Program
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