1、BRITISH STANDARD BS EN 13925-3:2005 Non destructive testing X ray diffraction from polycrystalline and amorphous materials Part 3: Instruments The European Standard EN 13925-3:2005 has the status of a British Standard ICS 19.100 BS EN 13925-3:2005 This British Standard was published under the author
2、ity of the Standards Policy and Strategy Committee on 9 July 2005 BSI 9 July 2005 ISBN 0 580 46085 1 National foreword This British Standard is the official English language version of EN 13925-3:2005. The UK participation in its preparation was entrusted to Technical Committee WEE/46, Nondestructiv
3、e testing, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue
4、under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct
5、application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informe
6、d; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 41 and a back cover. The BSI copyright notice displayed in this document indicates when the document
7、was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13925-3 May 2005 ICS 19.100 English version Non destructive testing - X ray diffraction from polycrystalline and amorphous materials - Part 3: Instruments Essais non destru
8、ctifs - Diffraction des rayons X applique aux matriaux polycristallins et amorphes - Partie 3: Appareillage Zerstrungsfreie Prfung - Rntgendiffraktometrie von polykristallinen und amorphen Materialien - Teil 3: Gerte This European Standard was approved by CEN on 21 March 2005. CEN members are bound
9、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 Cent
10、ral 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
11、the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spa
12、in, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national
13、 Members. Ref. No. EN 13925-3:2005: EEN 13925-3:2005 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Description of equipment .5 4.1 General5 4.2 X-ray sources .6 4.2.1 General6 4.2.2 Conventional X-ray sources (sealed tubes and rotating
14、anode sources) .6 4.2.3 Synchrotron radiation sources 6 4.3 Incident and diffracted X-ray beam optics 7 4.3.1 General7 4.3.2 Monochromators7 4.3.3 Beam dimensions and geometry .10 4.4 Detectors 12 4.4.1 Types of detector.12 4.4.2 Spatial resolution of detectors.14 4.4.3 Energy resolution of detector
15、s.14 4.5 Goniometers.14 4.5.1 General14 4.5.2 Specimen positioning .16 4.6 Specimen stage17 4.7 Data collection system18 5 Characterisation of equipment components 18 6 Equipment alignment and calibration .23 6.1 General23 6.2 Alignment .23 6.3 Calibration 23 7 Performance testing and monitoring.23
16、Annex A (informative) Relationship between the XRPD standards .25 Annex B (informative) Alignment of Bragg-Brentano diffractometers 26 Annex C (informative) Procedures for instrument performance characterisation .27 C.1 General27 C.2 Position, intensity and breadth of a limited number of diffraction
17、 lines .27 C.3 Angular Deviation Curve.27 C.4 Line breadth .30 C.5 Intensity diagrams .30 C.6 Shape Analysis Curve .30 C.7 Lattice parameters.31 C.8 The use of the Fundamental Parameter Approach 31 C.9 Whole pattern fitting32 Annex D (informative) Sample report forms for characterisation of instrume
18、nts 33 Bibliography 40EN 13925-3:2005 (E) 3 Foreword This document (EN 13925-3:2005) has been prepared by Technical Committee CEN/TC 138 “Non destructive testing”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publicatio
19、n of an identical text or by endorsement, at the latest by November 2005, and conflicting national standards shall be withdrawn at the latest by November 2005. This European Standard about “Non destructive testing - X-ray diffraction from polycrystalline and amorphous material” is composed of: - prE
20、N 1330-11, Terminology - Part 11: X-Ray Diffraction from Polycrystalline and Amorphous Materials - EN 13925-1, Part 1:General principles - EN 13925-2, Part 2: Procedures - EN 13925-3 Part 3: Instruments - WI 00138070, Reference Materials In order to explain the relationship between the topics descri
21、bed in the different standards, a diagram illustrating typical operation involved in XRPD is given in Annex A. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, C
22、zech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 13925-3:2005 (E) 4 Introduction X-ray powder diffrac
23、tion (XRPD) is a powerful Non-Destructive Testing (NDT) method for determining a range of physical and chemical characteristics of materials. These include the type and quantities of phases present, the crystallographic unit cell and structure, crystallographic texture, macrostress, crystallite size
24、 and microstrain, and the electron radial distribution function. This document aims to describe the general aspects of the XRPD technique and its applications but not to define a specific or detailed standard for each field of application or type of analysis. The main purposes of the standard are th
25、erefore to provide: practical guidance, unified concepts and terminology for use of the XRPD technique in the area of Non- Destructive Testing with general information about its capabilities and limitations of relevance to laboratories working at different levels of sophistication, from routine test
26、ing to research; a basis for Quality Assurance in XRPD laboratories allowing performance testing and monitoring of instruments as well as the comparison of results from different instruments; a general basis (without imposing specifications) for further specific NDT product standards and related Qua
27、lity Assurance applications, with aspects common to most fields of application. In order to make the standard immediately usable in a wide range of laboratories and applications, diffractometers with Bragg-Brentano geometry are considered in more detail than other instruments. Radiation Protection:
28、Exposure of any part of the human body to X-rays can be injurious to health. It is therefore essential that whenever X-ray equipment is used, adequate precautions should be taken to protect the operator and any other person in the vicinity. Recommended practice for radiation protection as well as li
29、mits for the levels of X-radiation exposure are established by national legislation in each country. If there are no official regulations or recommendations in a country, the latest recommendations of the International Commission on Radiological Protection should be applied. EN 13925-3:2005 (E) 5 1
30、Scope This document sets out the characteristics of instruments used for X-ray powder diffraction (“powder” as defined in EN 13925-1:2003, Clause 5) as a basis for their control and hence quality assurance of the measurements made by this technique. Performance testing indicators are given for diffr
31、actometer performance testing. Different types and makes of X-ray powder diffractometer vary considerably in their design and intended fields of application. This document attempts to cover as much of this range as possible by keeping to common principles. To make the standard more readily applicabl
32、e, the Bragg-Brentano configuration is addressed in most detail because of its wide use. Additional considerations and adaptations may be necessary to cover some types of instruments or configuration and some fields of application. Some of these types of instrument are described in Annex B. 2 Normat
33、ive references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 13925-2:2003, Non-destructive t
34、esting X-ray diffraction from polycrystalline and amorphous materials Part 2: Procedures prEN 1330-11:2004, Non-destructive testing Terminology Part 11: X-ray Diffraction from Polycrystalline and Amorphous Materials 3 Terms and definitions For the purposes of this document, the terms and definitions
35、 of prEN 1330-11:2004 apply. 4 Description of equipment 4.1 General This description is particularly intended for instruments dedicated to the fields of application described in EN 13925-1. For other applications, additional considerations may be required. A diffractometer generally comprises: gonio
36、meter; X-ray source; incident beam optics which may include monochromatisation or filtering, collimation and/or focusing or parallelism of the beam; diffracted beam optics which may include monochromatisation or filtering, collimation and/or focusing or parallelism of the beam; specimen stage; detec
37、tor; data collection system. These parts of the instrument are considered in more detail below. A data processing system is also required to produce measurements from the instrument. Data processing systems, whether manual or computerised, shall be included with the data processing procedures of EN
38、13925-2. EN 13925-3:2005 (E) 6 A well-controlled environment (temperature and pressure) is strongly recommended for analysis where reproducible measurement of line profile position, width and shape is required. Humidity is may be important because compounds in the specimen may react with water or ab
39、sorb it with a consequent change in their lattice constants, e.g. clay minerals. The X-ray beam is partially scattered and attenuated by the air in the beam path with consequential effects on the detected diffraction pattern background and intensity. This effect has sometimes been minimised by use o
40、f an evacuated or helium filled beam path. For all the items described in this clause the corresponding main characteristics to be controlled are given in Clause 5. 4.2 X-ray sources 4.2.1 General There are several types of x-ray source that can be used for XRPD measurements ranging from conventiona
41、l laboratory sources to intense and well-collimated synchrotron sources. Each source exhibits characteristics that make it more suitable for particular types of analysis. The main source types are described below. 4.2.2 Conventional X-ray sources (sealed tubes and rotating anode sources) X-rays are
42、obtained by bombarding a metal anode with electrons emitted by the thermoionic effect and accelerated in a strong electric field produced by a high-voltage generator. Most of the kinetic energy of the electrons is converted to heat, which limits the power of the tubes and requires efficient anode co
43、oling. An increase of about two orders of magnitude in brilliance can be obtained using rotating anodes instead of sealed tubes. Microfocus sources operate at relatively low power settings but maintain brightness by electrostatically or magnetically steering the beam inside the X-ray tube onto the t
44、arget. The spectrum emitted by a conventional X-ray source operating at sufficiently high voltage consists firstly of a continuous background of polychromatic radiation with a sharp cut off at short wavelengths determined by the maximum voltage applied. Upon this is superimposed a limited number of
45、narrow characteristic lines whose wavelengths are characteristic of the anode material. The emitted radiation is not polarised. The type of X-ray source and the electron emission current, and accelerating voltage applied to it by the high voltage generator have a marked effect on X-ray intensity and
46、 its energy distribution. The emission current and accelerating voltage of a conventional X-ray tube normally give reproducible adjustment of the X-ray beam intensity and energy spectrum on a time scale of days. However, experience has shown that the absolute X-ray intensity differs significantly fo
47、r nominally equal sources and that it decreases with source age. 4.2.3 Synchrotron radiation sources A beam of charged particles strongly accelerated in an electric field and deflected in a magnetic field emits a continuous spectrum of X-rays that is as much as 10 13times as brilliant as sealed X-ra
48、y tubes. It is called “synchrotron radiation“. This increased brilliance relates to the total energy spectrum. Monochromatisation of the beam typically results in diffraction intensities one or two orders of magnitude greater than from conventional sources. The main advantages of using synchrotron r
49、adiation for XRPD measurements are: - nearly parallel-beam diffraction geometry; - highly monochromatised and tunable radiation; - very small and almost symmetric contribution of the instrument to the observed line shape that leads to simpler characterisation of line profiles and very good angular resolution. EN 13925-3:2005 (E) 7 This type of X-ray radiation source requires beam flux monitoring with time (the beam flux can decrease significantly during the experiment) an
