www bzfxw com BRITISH STANDARD BS EN 725 3 1994 Advanced technical ceramics — Methods of test for ceramic powders — Part 3 Determination of the oxygen content of non oxides by thermal extraction with[.]
BRITISH STANDARD Advanced technical ceramics — Methods of test for ceramic powders — Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas The European Standard EN 725-3:1994 has the status of a British Standard UDC 666.3-121:620.1:546.21 BS EN 725-3:1994 BS EN 725-3:1994 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom This British Standard, having been prepared under the direction of the Refractory Products Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 May 1994 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference RPM/14 Draft for comment 92/39462 DC ISBN 580 22393 Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standardiseringsraad Suomen Standardisoimisliito, r.y Association franỗaise de normalisation Deutsches Institut für Normung e.V Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Nederlands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portugs da Qualidade Asociación Espola de Normalización y Certificación Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 725-3:1994 Contents Cooperating organizations National foreword Foreword Text of EN 725-3 National annex NA (informative) Committees responsible © BSI 11-1999 Page Inside front cover ii Inside back cover i BS EN 725-3:1994 National foreword This British Standard has been prepared under the direction of the Refractory Products Standards Policy Committee and is the English language version of EN 725-3:1994, Advanced technical ceramics — Methods of test for ceramic powders — Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas, published by the European Committee for Electrotechnical Standardization (CEN) EN 725-3 was produced as a result of international discussions in which the UK took an active part A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages to 6, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 11-1999 EUROPEAN STANDARD EN 725-3 NORME EUROPÉENNE January 1994 EUROPÄISCHE NORM UDC 666.3-121:620.1:546.21 Descriptors: Ceramics, powdery materials, chemical analysis, determination of content, oxygen, extraction methods, reduction methods, carbon monoxide English version Advanced technical ceramics — Methods of test for ceramic powders — Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas Céramiques techniques avancées — Méthodes d’ essai pour poudres céramiques — Partie 3: Détermination de la teneur en oxygène de poudres non-oxydes par extraction chaud sous gaz porteur Hochleistungskeramik — Prüfverfahren für keramische Pulver — Teil 3: Bestimmung des Sauerstoffgehaltes in Nichtoxid-Pulvern mittels Trägergasheißextraktion ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ This European Standard was approved by CEN on 1994-01-10 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1994 Copyright reserved to CEN members Ref No EN 725-3:1994 E EN 725-3:1994 Foreword This European Standard has been prepared by Technical Committee CEN/TC 184, Advanced technical ceramics, the secretariat of which is held by BSI EN 725 consists of 11 Parts: — Part 1: Determination of impurities in alumina; — Part 2: Determination of impurities in barium titanate (ENV); — Part 3: Determination of oxygen content of non-oxides by thermal extraction with a carrier gas; — Part 4: Determination of oxygen content in aluminium nitride by XRF analysis (ENV); — Part 5: Determination of particle size distribution; — Part 6: Determination of the specific surface area; — Part 7: Determination of absolute density; — Part 8: Determination of tapped bulk density; — Part 9: Determination of untamped bulk density; — Part 10: Determination of compaction properties; — Part 11: Determination of densification on natural sintering (ENV) This document was submitted for the Formal Vote and approved as a European Standard This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 1994, and conflicting national standards shall be withdrawn at the latest by July 1994 In accordance with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom Contents Foreword Scope Principle Apparatus Sample preparation Procedure Blank determination Calibration Test report Annex A (informative) Guidance in the selection of test conditions Page 3 3 3 ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ © BSI 11-1999 EN 725-3:1994 Scope Sample preparation This Part of EN 725 describes a method for the determination of the oxygen content of non-oxide powders used for advanced technical ceramics, using an inert carrier gas thermal extraction method The method is suitable for oxygen contents of less than % Take a sample of the dry powder, the quantity taken being based on the detection limit of the apparatus used for gas analysis and on the expected oxygen content of the powder NOTE The limits of determination are given by the manufacturers of the apparatus Principle A test piece is heated in a graphite crucible at a high temperature in a flow of an inert carrier gas Oxygen in the sample is converted to oxides of carbon, which are extracted and transformed to consist entirely of either carbon monoxide or carbon dioxide This volume is then determined by a suitable method of gas analysis NOTE Guidance on the selection of test conditions is given in Annex A Apparatus 3.1 Graphite crucible, which is used as a carbon source The crucible is capable of being electrically heated by two electrodes, or by induction NOTE For example, for infrared absorption (see 3.4 e), samples of 100 mg to 300 mg are required Use a scoop to handle the powder and place the sample either directly in the crucible or in the tin capsule If the capsule is used, squeeze it to expel air and then fold over the open end several times, weighing again after squeezing Procedure 5.1 Heat the empty graphite crucible inside the furnace to a temperature greater than the temperature for analysis Record the flow of gas used in the furnace NOTE This is to prevent additional degassing of the crucible during the test run, which would produce errors NOTE A recommendation for gas flow will normally be given by the manufacturer of the instrument Cool to ambient temperature 5.2 Place the tin capsule and sample in the crucible Select a temperature which is high enough to dissociate the oxides to be determined (see Annex A) Use the nickel wire basket (see 3.3) if the preliminary tests suggest that it is necessary Heat the furnace to the test temperature and record the temperature and the time at temperature Collect the gas evolved and measure the amount, using one of the analytical techniques listed in 3.4 5.3 Repeat the procedure given in clause and subclause 5.2 at least four times ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ 3.2 Tin capsule, (optional) to contain the ceramic powder sample 3.3 Nickel wire basket, (optional) for use as a fluxing agent with certain powders such as aluminium nitride 3.4 Gas analysis apparatus, based on one of the following techniques: a) volumetric analysis, for measurement of carbon monoxide gas; b) chromatography, for carbon monoxide; c) thermal conductivity, for carbon monoxide and carbon dioxide; d) coulometric analysis, for carbon dioxide; e) infrared absorption, for carbon dioxide 3.5 Furnace, normally capable of reaching at least 500 °C operating in an inert gas atmosphere (nitrogen, helium or argon) NOTE Apparatus which does not achieve 500 °C may be used for lower test temperatures, but 500 °C will be needed to give the correct result for certain types of material © BSI 11-1999 Blank determination Carry out a blank determination for the apparatus whenever the gas supply or crucible batch is changed Use the procedure given in clause and record the amount of gas evolved Use this blank value to calculate the results for the sample analysis Calibration Calibration shall be carried out preferably by using a reference material of certified oxygen content to calibrate the furnace and gas analysis equipment, using the procedure given in clause An alternative method is to use a sample of pure carbon monoxide or carbon dioxide gas to calibrate the gas analysis equipment, with a minimum of three results being recorded EN 725-3:1994 Test report The test report shall include the following information: a) the name of the test establishment; b) the date of the test, a unique identification of the report, the name and address of the customer, a signatory of the report; c) a reference to this European Standard, i.e determined in accordance with EN 725-3; d) a description of the test material (manufacturer, type, batch or code number); e) the type of analytical equipment used (see 3.4); f) the method of calibration (see clause 7); g) the purity of the carrier gas and gas used for calibration; h) the mass of the samples and reference to optional use of the tin capsule (see 3.2); i) the test temperature; j) the individual values of oxygen content, mean value and standard deviation: k) comments about the test or test results ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ © BSI 11-1999 EN 725-3:1994 Annex A (informative) Guidance in the selection of test conditions Because of the large variety of ceramic powders in use and number of analytical techniques available, it is not possible to specify test conditions (amount of sample, temperature, gas flow rate, analytical technique) that will be applicable to every determination It is therefore recommended that the optimum conditions for testing a material be determined by preliminary tests This may be done by carrying out successive tests on the same test sample, increasing the reducing action until the measured oxygen content reaches a maximum, constant value Fluxing agents (see 3.3) may also be used When the test conditions have been established, a certified reference material of the same chemical type as the test sample should be tested to check these proposed conditions ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ © BSI 11-1999 ｗｗｗ．ｂｚｆｘｗ．ｃｏｍ blank BS EN 725-3:1994 National annex NA (informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Refractory Products Standards Policy Committee (RPM/-) to Technical Committee RPM/14 upon which the following bodies were represented: British Ceramic Research Ltd British Industrial Ceramic Manufacturers’ Association British Steel Industry Bureau of Analysed Samples Limited China Clay Association Ministry of Defence Refractories Association of Great Britain Society of Glass Technology © BSI 11-1999 BS EN 725-3:1994 BSI — British Standards Institution BSI is the independent 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