DIN EN 15979-2011 Testing of ceramic raw and basic materials - Direct determination of mass fractions of impurities in powders and granules of silicon carbide by OES by DC arc exci.pdf

1、April 2011 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、81.060.10!$nm“1757495www.din.deDDIN EN 15979Testing of ceramic raw and basic materials Direct determination of mass fractions of impurities in powders andgranules of silicon carbide by OES by DC arc excitationEnglish translation of DIN EN 15979:2011-04Prfung keramischer Roh- und Werkstoffe Direkte B

3、estimmung der Massenanteile an Verunreinigungen in pulver- und kornfrmigemSiliciumcarbid mittels OES und Anregung im GleichstrombogenEnglische bersetzung von DIN EN 15979:2011-04Essai des matires premires et matriaux de base cramiques Dtermination directe des fractions massiques dimpurets dans les p

4、oudres et granulsde carbure de silicium par OES lexcitation darc DCTraduction anglaise de DIN EN 15979:2011-04SupersedesDIN 51088:2007-12www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.03.11 24DIN EN 15979:2011-04 2 A comma is used

5、 as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 187 “Refractory products and materials” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standa

6、rds Committee), Working Committee NA 062-02-64 AA Chemische Analyse von nichtoxidischen keramischen Roh- und Werkstoffen. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 5725-1 DIN ISO 5725-1 ISO 5725-4 DIN ISO 5725-4 ISO 8656-1 DIN 510

7、61-2 and DIN EN 1402-2 Amendments This standard differs from DIN 51088:2007-12 as follows: a) the standard has been editorially revised. Previous editions DIN 51088: 2007-12 National Annex NA (informative) Bibliography DIN 51061-2, Testing of ceramic raw and finished materials Part 2: Sampling of ce

8、ramic raw materials DIN EN 1402-2, Unshaped refractory products Part 2: Sampling for testing DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions DIN ISO 5725-4, Accuracy (trueness and precision) of measurement methods and re

9、sults Part 4: Basic methods for the determination of the trueness of a standard measurement method EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15979 January 2011 ICS 81.060.10 English Version Testing of ceramic raw and basic materials - Direct determination of mass fractions of impurities i

10、n powders and granules of silicon carbide by OES by DC arc excitation Essai des matires premires et matriaux de base cramiques - Dtermination directe des fractions massiques dimpurets dans les poudres et granuls de carbure de silicium par OES lexcitation darc DC Prfung keramischer Roh- und Werkstoff

11、e - Direkte Bestimmung der Massenanteile an Verunreinigungen in pulver- und kornfrmigem Siliciumcarbid mittels OES und Anregung im Gleichstrombogen This European Standard was approved by CEN on 10 December 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulat

12、e 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 CEN-CENELEC Management Centre or to any CEN member. This European Stan

13、dard 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 CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the nat

14、ional standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switze

15、rland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. E

16、N 15979:2011: EEN 15979:2011 (E) 2 Contents Page Foreword 31 Scope 42 Principle 43 Spectrometry 44 Apparatus .45 Reagents .56 Sampling and preparation of test samples .57 Calibration 58 Procedure .69 Calculation 810 Expression of results 811 Precision .812 Test report 9Annex A (informative) Results

17、of inter-laboratory study 10Annex B (informative) Wavelength and working range 14Annex C (informative) Possible interferences and their elimination 16Annex D (informative) Information regarding the evaluation of the uncertainty of the mean value . 19Annex E (informative) Commercial certified referen

18、ce materials 20Bibliography . 21DIN EN 15979:2011-04 EN 15979:2011 (E) 3 Foreword This document (EN 15979:2011) has been prepared by Technical Committee CEN/TC 187 “Refractory products and materials”, the secretariat of which is held by BSI. This European Standard shall be given the status of a nati

19、onal standard, either by publication of an identical text or by endorsement, at the latest by July 2011, and conflicting national standards shall be withdrawn at the latest by July 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rig

20、hts. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,

21、Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15979:2011-04 EN 15979:201

22、1 (E) 4 1 Scope This European Standard describes the method for the analysis of mass fractions of the impurities Al, B, Ca, Cr, Cu, Fe, Mg, Ni, Ti, V and Zr in powder- and grain-shaped silicon carbide of ceramic raw and basic materials. This application can also be extended to other metallic element

23、s and other similar non-metallic powder- and grain-shaped materials such as carbides, nitrides, graphite, carbon blacks, cokes, carbon, as well as a number of further oxidic raw and basic materials after appropriate testing. NOTE There are positive interferences for materials such as e.g. graphite,

24、B4C, BN, WC and several refractory metal oxides. This testing procedure is applicable to mass fractions of the impurities mentioned above from approximately 1 mg/kg up to approximately 3 000 mg/kg, after verification. In some cases it may be possible to extend the range up to 5 000 mg/kg depending o

25、n element, wavelength, arc parameter, and sample weight. 2 Principle The combustion and evaporation of the crushed sample material takes place in the arc in an atmosphere of mixed argon and oxygen or in air. The metallic traces in the arc plasma are excited to emission of light. The light is guided

26、into a simultaneous emission spectrometer (e.g. by coupling via fibre-optics or directly). The light is split in its spectral lines and measured by applicable detectors like a photomultiplier, charge coupled device (CCD), and charge injection device (CID). The mass fractions of elements in the sampl

27、e are calculated by comparison of the intensities of the element-specific spectral line with those of a calibration sample of identical material. 3 Spectrometry The optical emission spectrometry is based on generation of line spectra of excited atoms or ions, in which each spectral line can be defin

28、itely related to an element and the line intensities are proportional to the mass fractions of elements in the measured sample (see 6, 7 b) The carrier electrode is filled by repeatedly pressing the cup (orifice downwards) onto the sample material which is lying on a clean carrier (e.g. filter paper

29、); c) A sub-sample of the sample material is weighed to the nearest 0,1 mg into the carrier electrode in a defined narrow weighing range (e.g. between 4,5 to 5,5 mg). The mass of the weighed sub-sample has to be documented. Depending on dimension and shape of the carrier electrode the mass of the su

30、b-sample can vary. The sample mass can be reduced in case of elements, e.g. with mass fractions above the calibration range (minimum circa 1 mg). In this case, the weighed sub-sample has to be mixed in the electrode with a material of the same type, which does not contain the respective analytes. Th

31、e total mass of material in the electrode shall correspond to that of the calibration sample (5.2). Instead of a pure material of the same type spectral-grade carbon powder can be used. Subsequently, the sub-sample has to be compacted in the cup of the carrier electrode by slightly striking it on a

32、rigid underlay or by knocking with a spatula at the tweezers holding the carrier electrode. The electrodes shall be touched in the clamp-region of the electrode holder using tweezers (4.3) The carrier electrode has to be fixed in the optical path using the electrode holder of the DC-Arc equipment. T

33、he distance to the upper counter electrode (cathode) has to be adjusted to the nearest 0,1 mm at a value of 3,5 mm to 4,0 mm. NOTE 1 The distance between the electrodes can vary according to the diameter of the electrodes. The position of the electrodes, and thus the arc discharge, has to be constan

34、t with respect to the optical axis of the optical system. Any change of the optical adjustment will lead to different results. Parts of the electrodes shall not be visible to the emission spectrometer. This is especially true for the upper electrode (cathode) whereas the lower electrode (anode), bec

35、ause of the high burn-off rate, normally remains a significantly shorter time in the optical path. NOTE 2 Electrodes visible in the optical path result in a strong enhancement of the spectral background in some spectral ranges. The arc discharge has to be started synchronous to the data acquisition

36、of the spectrometer (4.1). DIN EN 15979:2011-04 EN 15979:2011 (E) 7 The evaporation or combustion of the sample in the DC-Arc has to be carried out preferably under shielding gas excluding any nitrogen. The mixing ratio of the shielding gas is about 70 parts by volume argon and 30 parts by volume ox

37、ygen at a constant gas flow of about (4 1) l/min. The evaporation or combustion in air is principally possible, but then one has to pay attention to spectral interferences, e.g. CN-bands. In addition, degradation of the reproducibility can be expected. CAUTION It is not safe to look into the arc pla

38、sma without eye protection (UV- and IR-radiation). Reflections on reflective areas can be dangerous too. Each sample shall be measured a minimum of three times. 8.2 Procedure using addition of carrier This procedure is especially suitable for low analyte concentrations. The sample shall be weighed t

39、ogether with carrier and spectral-grade carbon or graphite. The mixture is homogenised using an easy volatile solvent. The optimal relation of quantities as well as the selection of an appropriate carrier (see 2 and 11) shall be investigated for each sample material experimentally. NOTE 1 The power

40、of detection is advanced by addition of carrier. Suitable carriers are halides like AgCl, BaCl2. NOTE 2 For materials such as SiC and WC and also for oxides such as MoO3, WO3, Ta2O3, Nb2O3, it is recommended to use BaCl2as carrier and a mass-ratio of sample/graphite/BaCl2of 10/4/1. In the individual

41、 case the ratio should be checked and, if necessary, be optimized. NOTE 3 The sample mix can be homogenized in a plastic bottle (4.8) after addition of 6 ml dichloromethane and about 20 stirring balls (4.7). Shake the bottle for a minimum of 10 min. The dichloromethane can be completely removed by p

42、lacing the opened plastic bottle in a drying cabinet for approximately 1 h at 60 C. The dried mixture is loosened by gently shaking the plastic bottle. After that, the stirring balls can be removed. CAUTION To avoid exposure to dichloromethane, the appropriate safety regulations shall be obeyed. Fil

43、ling of the carrier electrode shall be carried out in accordance with 8.1. The samples used for calibration (5.2) shall be treated in the same manner. Each sample has to be measured a minimum of three times. If the deviation of the single values of the analyte concentrations is greater than the spec

44、ified value of repeatability, the procedure has to be repeated according to Clause 8. In the case of continued insufficient reproducibility of spectral line intensities of one or more analytes the sample has to be homogenised additionally (e.g. mortar). For low concentrations near the limit of deter

45、mination (see 16) this further step is not necessary. 8.3 Wavelength and working range It is critical that all selected analyte wavelength are interference-free with respect to sample matrix and further impurities. NOTE 1 Proposal for selection of wavelength and information about working ranges, see

46、 Annex B. Only spectral lines shall be selected where under the chosen working conditions neither self-absorption nor self-reversal will occur. Order-interferences mainly occur when combining Echelle optics with plane solid-state detectors (CID- or CCD-detectors). NOTE 2 A comprehensive description

47、of possible interferences and their reduction can be found in Annex C. DIN EN 15979:2011-04 EN 15979:2011 (E) 8 Ensure that the concentrations to be analyzed lie above the limits of determination of the analytes. The upper working range is limited by a decrease of sensitivity (slope of calibration f

48、unction) to about 80 % of its initial value. If applicable, less sensitive spectral lines can be used. 9 Calculation The intensities of spectral lines measured by the emission spectrometer (4.1) shall be corrected to net-intensities using the background intensities measured at the background measuri

49、ng points. The net-intensities shall be converted into the corresponding masses of the respective analytes using analytical functions. These include the weight of the sub-samples, so the mass fractions of the analytes in the original sample can be calculated. Additionally, the ratio of the net-intensities of the analyte lines to the intensity of an emission line of a reference element with constant mass fraction (e.g. Si in analysis of SiC) can also be ca