SANS 3497-2008 Metallic coatings - Measurement of coating thickness - X-ray spectrometric methods《金属镀层 涂层厚度测量 X射线光谱法》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21898-0 SANS 3497:2008Edition 2 ISO 3497:2000Edition 3SOUTH AFRICAN NATIONAL STANDARD Metallic coatings Measurement of coating thickness X

4、-ray spectrometric methods This national standard is the identical implementation of ISO 3497:2000 and is adopted with the permission of the International Organization for Standardization. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428

5、 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 3497:2008 Edition 2 ISO 3497:2000 Edition 3 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SABS TC 107, Metallic and other inorganic coatings, in accordance with procedures of

6、 the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in November 2008. This SANS document supersedes SABS ISO 3497:1990 (first edition). Reference numberISO 3497:2000(E)ISO 2000INTERNATIONALSTANDARDISO3497Third edition2000-12-15Metallic

7、coatings Measurementof coating thickness X-ray spectrometricmethodsRevtements mtalliques Mesurage de lpaisseur du revtement Mthodes par spectromtrie de rayons XSANS 3497:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 3497:2000(E)PDF

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13、ts of the SABS .ISO 3497:2000(E) ISO 2000 All rights reserved iiiContents PageForeword.iv1 Scope 12 Terms and definitions .13 Principle34 Apparatus .75 Factors that influence the measurement results106 Calibration of instrument 147 Procedure .168 Measurement uncertainty .179 Test report 17Annex A (i

14、nformative) Typical measuring ranges for some common coating materials 18SANS 3497:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 3497:2000(E)iv ISO 2000 All rights reservedForewordISO (the International Organization for Standardizat

15、ion) is a worldwide federation of national standards bodies (ISOmember bodies). The work of preparing International Standards is normally carried out through ISO technicalcommittees. Each member body interested in a subject for which a technical committee has been established hasthe right to be repr

16、esented on that committee. International organizations, governmental and non-governmental, inliaison with ISO, also take part in the work. ISO collaborates closely with the International ElectrotechnicalCommission (IEC) on all matters of electrotechnical standardization.International Standards are d

17、rafted in accordance with the rules given in the ISO/IEC Directives, Part 3.Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote

18、.Attention is drawn to the possibility that some of the elements of this International Standard may be the subject ofpatent rights. ISO shall not be held responsible for identifying any or all such patent rights.International Standard ISO 3497 was prepared by Technical Committee ISO/TC 107, Metallic

19、 and other inorganiccoatings, Subcommittee SC 2, Test methods.This third edition cancels and replaces the second edition (ISO 3497:1990), which has been technically revised.Annex A of this International Standard is for information only.SANS 3497:2008This s tandard may only be used and printed by app

20、roved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO 3497:2000(E) ISO 2000 All rights reserved 1Metallic coatings Measurement of coating thickness X-ray spectrometric methods1 ScopeWARNING Problems concerning protection of personnel against X-rays are not covered by thi

21、sInternational Standard. For information on this important aspect, reference should be made to currentinternational and national standards, and to local regulations, where these exist.1.1 This International Standard specifies methods for measuring the thickness of metallic coatings by the use ofX-ra

22、y spectrometric methods.1.2 The measuring methods to which this International Standard applies are fundamentally those that determinethe mass per unit area. Using a knowledge of the density of the coating material, the results of measurements canalso be expressed as linear thickness of the coating.1

23、.3 The measuring methods permit simultaneous measurement of coating systems with up to three layers, orsimultaneous measurement of thickness and compositions of layers with up to three components.1.4 The practical measurement ranges of given coating materials are largely determined by the energy of

24、thecharacteristic X-ray fluorescence to be analysed and by the acceptable measurement uncertainty and can differdepending upon the instrument system and operating procedure used.2 Terms and definitionsFor the purposes of this International Standard, the following terms and definitions apply.2.1X-ray

25、 fluorescenceXRFsecondary radiation occurring when a high intensity incident X-ray beam impinges upon a material placed in thepath of the incident beamNOTE The secondary emission has wavelengths and energies characteristic of that material.2.2intensity of fluorescent radiationradiation intensity, x,

26、 measured by the instrument, expressed in counts (radiation pulses) per second2.3saturation thicknessthickness that, if exceeded, does not produce any detectable change in fluorescent intensityNOTE Saturation thickness depends upon the energy or wavelength of the fluorescent radiation, density and a

27、tomicnumber of the material and on the angle of incident and fluorescent radiation with respect to the surface of the material.SANS 3497:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 3497:2000(E)2 ISO 2000 All rights reserved2.4norm

28、alized intensityxnratio of the difference in intensity obtained from a coated specimen, x, and an uncoated substrate material, x0,andthe difference obtained from a material of thickness equal to or greater than the saturation thickness, xs(see 2.3)and an uncoated substrate material, x0, all measured

29、 under the same conditionsNOTE 1 The mathematical relationship is given by:0ns0xxxxxG2dG3dG2dwherex is the intensity obtained from the coated specimen;x0is the intensity obtained from uncoated substrate material;xsis the intensity obtained from a material of thickness equal to or greater than the sa

30、turation thickness.NOTE 2 The normalized intensity is independent of measurement and integration time, and intensity of the excitation(incident radiation). The geometric configuration and the energy of the excitation radiation can influence the normalized countrate. The value of xnisvalidbetween0and

31、1.2.5intermediate coatingscoatings that lie between the top coating and the basis material and are of thicknesses less than saturation foreach of the coatingsNOTE Any coating lying between the top coating and the basis material (substrate) and having a thickness abovesaturation should itself be cons

32、idered the true substrate since the material under such a coating will not affect the measurementand can be eliminated for measurement purposes.2.6count ratenumber of radiation pulses recorded by the instrument per unit time (see 2.2).2.7basis materialbasis metalmaterial upon which coatings are depo

33、sited or formedISO 2080:1981, definition 1342.8substratematerial upon which a coating is directly depositedNOTE For a single or first coating the substrate is identical with the basis material; for a subsequent coating theintermediate coating is the substrate.ISO 2080:1981, definition 630SANS 3497:2

34、008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 3497:2000(E) ISO 2000 All rights reserved 33Principle3.1 Basis of operationA relationship exists between mass per unit area of the coating (and thus the linear coating thickness if the de

35、nsityis known) and the secondary radiation intensity. This relationship, for any practical instrument system, is firstestablished by calibrating using calibration standards having coatings of known mass per unit area. If the coatingmaterial density is known, such standards can have coatings given in

36、 linear thickness units, provided that theactual density value is also given.NOTE The coating material density is the density as-coated, which may or may not be the theoretical density of the coatingmaterial at the time the measurement is made. If this density differs from the density of the calibra

37、tion standards, a factor thatreflects this difference is used and documented in the test report.The fluorescent intensity is a function of the atomic number of the elements. Providing the top coating, intermediatecoating (if present) and the substrate are of different elements or a coating consists

38、of more than one element,these elements will generate radiation characteristics for each of them. A suitable detector system can be adjustedto select either one or more energy bands, enabling the equipment to measure thickness and/or composition ofeither the top coating or the top and some intermedi

39、ate coatings simultaneously.3.2 Excitation3.2.1 GeneralThe measurement of the thickness of coatings by X-ray spectrometric methods is based on the combinedinteraction of the coating (or coatings) and substrate with an intense, often narrow, beam of polychromatic ormonochromatic X-radiation. This int

40、eraction results in generating discrete wavelengths or energies of secondaryradiation which are characteristic of the elements composing the coating(s) and substrate.The generated radiation is obtained from a high voltage X-ray tube generator or from suitable radioisotopes.3.2.2 Generation by a high

41、 voltage X-ray tubeSuitable excitation radiation will be produced by an X-ray tube if sufficient potential is applied to the tube and stableconditions apply. Applied voltages are in the order of 25 kV to 50 kV for most thickness requirements but voltagesdown to 10 kV may be necessary in order to mea

42、sure low atomic number coating materials. For some applicationsthe use of a primary filter, located between the X-ray tube and the specimen, decreases the measurementuncertainty.The chief advantages of this method of excitation areGbe the ability to create, by collimation, a very high intensity beam

43、 on a very small measurement area;Gbe the ease of control for personnel safety requirements;Gbe the potential stability of emission obtainable by modern electronic methods.3.2.3 Generation by a radioisotopeOnly a few radioisotopes emit gamma radiation in the energy band suitable for coating thicknes

44、s measurement.Ideally, the excitation radiation is of slightly higher energy (shorter in wavelength) than the desired characteristicX-rays. The advantages of radioisotope generation include the possibility of a more compact construction of theinstrument, due mainly to there being no need for cooling

45、. In addition, the radiation, unlike that from high voltageX-ray generators, is essentially monochromatic and there is low background intensity.SANS 3497:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 3497:2000(E)4 ISO 2000 All right

46、s reservedThe major technical disadvantages when compared with the X-ray tube method areGbe the much lower intensity that is obtained, which prohibits measurements on small areas;Gbe the short half-life of some radioisotopes;Gbe personnel protection problems associated with high intensity radioisoto

47、pes (the high voltage X-ray tube cansimply be switched off).3.3 Dispersion3.3.1 GeneralThe secondary radiation resulting from the exposure of a coated surface to X-ray radiation often containscomponents additional to those required for the measurement of coating thickness. The desired components are

48、separated by either wavelength or energy dispersion.3.3.2 Wavelength dispersionThe wavelength characteristic of either coating or substrate is selected using a crystal spectrometer. Typicalcharacteristic emission data for commonly used crystals are available in published form from various nationalau

49、thorities.3.3.3 Energy dispersionX-ray quanta are usually specified in terms of wavelength or equivalent energies. The relationship between thewavelength, G6c, in nanometres, and energy E, in kiloelectron-volts (keV), is given byG6c Gb4 E = 1,239 842 7.3.4 DetectionThe type of detector used for wavelength dispersive systems can be a gas-filled tube, a solid state detector orscintillation counter connected to a photomultiplier.The most suitable detector for receiving fluorescent photons and used in energy dispersive systems is selected