1、BRITISH STANDARD BS IEC 61336:1996 Nuclear instrumentation Thickness measurement systems utilizing ionizing radiation Definitions and test methods ICS 17.040.20; 17.240BSIEC 61336:1996 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was published undert
2、he authority of the Standards Board and comes intoeffect on 15 March 1998 BSI 04-1999 ISBN 0 580 29601 6 National foreword This British Standard reproduces verbatim IEC 61336:1996 and implements it as the UK national standard. It supersedes BS 5868:1983 which is withdrawn. The UK participation in it
3、s preparation was entrusted to Technical Committee NCE/2, Health physics instrumentation, which has the responsibility to: 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 i
4、nterests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number60000 added to the old number. For ins
5、tance, IEC27-1 has been renumbered as IEC60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards which implement international or European publications referred to in t
6、his document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Us
7、ers 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, theCEIIEC title page, pages ii to iv, p
8、ages 1 to 29 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. Amendments issued since publication Amd. No. Date CommentsBSIEC61336:1996 BSI 04-1999 i Contents Page
9、National foreword Inside front cover Foreword iii Text of CEIIEC 1336 1ii blankBS IEC61336:1996 ii BSI 04-1999 Contents Page Foreword iii Introduction 1 1 General 1 1.1 Scope and object 1 1.2 Normative references 2 1.3 Definitions 2 2 Test requirements 9 2.1 General 9 2.2 Laboratory tests 10 2.2.1 I
10、ntrinsic performance tests 10 2.2.2 Influence quantities and tests 17 2.2.3 Process and machine analysis and measurement system tests 21 2.3 Laboratory test results documentation 22 2.4 On-site tests 22 2.4.1 System sample profile error test 23 2.4.2 System profile and scan average reproducibility t
11、ests 23 2.4.3 Geometrical resolution length test 24 Annex A Mains supply voltage tests 25 Annex B Generalized measurement system description 25 Figure 1 Typical time response of a system to step increase of input 5 Figure 2 Typical time response of a digital system to step variation of input 6 Figur
12、e 3 Linearity 8 Figure B.1 Functional block diagram of generalized measurement system 26BS IEC 61336:1996 BSI 04-1999 iii Foreword 1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National
13、Committees). The object of the IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, the IEC publishes International Standards. Their preparation is entrusted to technical com
14、mittees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. The IEC collaborates closely with the International Organizati
15、on for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical
16、committee has representation from all interested National Committees. 3) The documents produced have the form of recommendations for international use and are published in the form of standards, technical reports or guides and they are accepted by the National Committees in that sense. 4) In order t
17、o promote international unification, IEC National Committees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corresponding national or regional standard shall be clea
18、rly indicated in the latter. 5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with one of its standards. 6) Attention is drawn to the possibility that some of the elements of this International Standar
19、d may be the subject of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 1336 has been prepared by IEC technical committee 45: Nuclear instrumentation. This standard cancels and replaces IEC769 published in 1983 and consti
20、tutes a technical revision. The text of this standard is based on the following documents: Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. Annex A forms an integral part of this standard. Annex B is for information o
21、nly. FDIS Report on voting 45/388/FDIS 45/404/RVDiv blankBSIEC61336:1996 BSI 04-1999 1 Introduction Since 1983, there have been many advances in the state-of-the-art technology that influence the test procedures which are in common use for measurement systems utilizing ionizing radiation. These incl
22、ude the following. Common usage of laboratory PC computers with data acquisition modules for nearly all primary performance measurement purposes, which means automated data collection; statistical data processing; more extensive use of calculated variables (such as thickness) instead of raw radiatio
23、n signals (such as volts or counts); spreadsheet presentation and manipulation of data and results; much larger data sets. New measurement system-related features for accessing measurement information such as: very high speed sampling; integrated work-station data logging, statistical data processin
24、g, and video/printer tabular and graphical data presentations; high resolution scanning measurement profiles; extensive data bases with long-term performance characteristics logging and reporting of trends; predictive failure analysis, etc. New design features to maximize absolute measurement accura
25、cy in adverse environments including such things as: elimination of errors due to foreign material (dirt) in the measurement path, temperature effects, electrostatic charge influences, vibration/microphonics; measurement air column compensation; internal measurement reference samples; microcomputers
26、 and microcontrollers built directly into the sensors. In light of the complexity of process control signals in current state-of-the-art technology with cross-machine controls, DCS architecture and other variations in control processes, this standard does not include the test point B of IEC769. The
27、original Appendix B has also been deleted as it is obsolete and inadequate in view of todays automated data collection methods and statistical data processing techniques. However, a number of new tests and test methods have been added to this standard. 1 General 1.1 Scope and object This standard re
28、lates to definitions, test methods, and procedures for ionizing radiation measurement systems designed for either continuous or discrete measurements and checks of mass per unit area, mass per unit length, or thickness of materials produced in industrial processes. The measured process material may
29、be in such forms as sheets, coatings, laminates, tubes, or rods. This standard applies to systems with one or more outputs for display or control purposes. The signals may be either analogue or digital. The measurement system may also include multiple input signals with various means of compensation
30、 and signal conditioning prior to the output signals. Safety aspects are covered in other IEC and ISO standards (for example IEC405, ISO2919, ISO7205). Consideration will also be given to compliance with all applicable national and local regulations and codes of practice. Thickness measurement syste
31、ms which are the object of this standard are generally built for industrial applications covering a very broad range of industries, applications, and specifications. The objective is to identify the common parameters and variables, and to specify standard tests and documentation that will facilitate
32、 direct comparison of the performance characteristics of the different measurement systems which are available. These tests are applicable to systems with either fixed or traversing measuring heads and with transmission, backscatter, or X-ray fluorescence sensors. Many ionizing radiation measurement
33、 systems in use today have multiple sensors, and employ various means of compensating the basic sensor signals to minimize the effects of extraneous influence quantities that introduce measurement errors. Dedicated microprocessors and minicomputers have further enhanced multiple input signal process
34、ing and error compensation techniques. In the more complex systems, it is difficult to fully evaluate the effectiveness of interactive signal processing and compensation algorithms by static testing. For example, the response times and data collection times for sensors, whose signals are to be combi
35、ned in some analytical function, are of little importance under the static testing conditions in this standard, but they can lead to large errors under dynamic measuring conditions if they are not properly matched. The relative magnitude of the influence quantity errors to be compensated is also qui
36、te important.BSIEC61336:1996 2 BSI 04-1999 The compensation means for sensors with high sensitivity to influence quantities should be more precise than for sensors which exhibit smaller errors in order to achieve the same overall results. Therefore, it is necessary to have performance tests, in the
37、standard, which may include all the interactive signal processing and compensations. This has been facilitated in this standard by identifying different test points throughout the measurement system under evaluation. It is important to estimate the potential performance degradation in adverse enviro
38、nments. Although it is difficult to duplicate exactly the influence of long-term and short-term process conditions during a limited test period, this set of procedures includes some artificially introduced environmental disturbances. In this standard the term “thickness” is used interchangeably to m
39、ean mass per unit area, mass per unit length, or thickness. Radiometric sensors, in general, measure mass per unit area and the output signals can be expressed in true thickness units only if the effective atomic number and density of the material being measured are known, or if the system is calibr
40、ated against actual production samples, and if the effective atomic number and density of the material produced do not change relative to those samples. In the case of rod-shaped products, with a known or constant cross-sectional area, the output signal may be expressed in terms of mass per unit len
41、gth. NOTEIt is recommended that the reader refers to the block diagram ofAnnex B for a better understanding of the specification. 1.2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard.
42、 At the time of publication, the editions indicated were valid. All normative documents are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated belo
43、w. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 359:1987, Expression of the performance of electrical and electronic measuring equipment. IEC 405:1972, Nuclear instruments: Constructional requirements to afford personal protection against ionizing radiati
44、on. ISO 2919:1980, Sealed radioactive sources Classification. ISO 7205:1986, Radionuclide gauges Gauges designed for permanent installation. 1.3 Definitions For the purpose of this International Standard the following definitions apply: 1.3.1 thickness gauge (ionizing radiation) a measuring assembly
45、 that includes an ionizing radiation source and is designed to measure non-destructively the mass per unit area of a material by means of ionizing radiation 1.3.2 transmission measurement system a thickness gauge system that utilizes the ionizing radiation transmitted through the material being meas
46、ured. The source and detector are positioned on opposite sides of the measured material. The system may include compensation sensors to measure and correct for the effects of undesirable influence quantities 1.3.3 backscatter measurement system a thickness gauge system that utilizes the ionizing rad
47、iation backscattered by the material being measured and any backing material adjacent to the material being measured. The source and detector are positioned on the same side of the material being measured. The system may include compensation sensors to measure and correct for the effects of undesira
48、ble influence quantities 1.3.4 X-ray fluorescence measurement system a thickness gauge system that utilizes the X-ray fluorescence excited in the material to be measured or in the supporting material the system may include compensation sensors to measure and correct for the effects of undesirable in
49、fluence quantities 1.3.5 measuring head a subassembly comprising one or more radiation sources and radiation detectors together with any compensation sensors that may be used to measure and correct the effects of undesirable influence quantities NOTEThe radiation source may be a radioactive sealed source or a radiation generator emitting X-rays of fixed or variable energy. The measuring head subassembly may also include electronic devices for signal processing.BSIEC61336:1996 BSI 04-1999 3 1.3.6 electronic measuring subassembly a subassembly which, by
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