BS EN 61262-3-1995 Characteristics of electro-optical X-ray image intensifiers for medical electrical equipment - Determination of the luminance distribution and luminance non-unif.pdf

1、BRITISH STANDARD BSEN 61262-3:1995 IEC1262-3: 1994 Characteristics of electro-optical X-ray image intensifiers for medical electrical equipment Part 3: Determination of the luminance distribution and luminance non-uniformity The European Standard EN61262-3:1994 has the status of a BritishStandardBSE

2、N61262-3:1995 This BritishStandard, having been prepared under the directionof the Health and Environment Sector Board (H/-), was published under the authorityof the Standards Boardand comes into effect on 15March1995 BSI01-2000 The following BSI references relate to the work on this standard: Commi

3、ttee reference HCC/72 Draft for comment 94/501343 DC ISBN 0 580 23594 7 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technical Committee HCC/72, Image intensifiers, upon which the following bodies were represented: Association of X-ray Equi

4、pment Manufacturers (BEAMA Ltd.) British Institute of Radiology College of Radiographers Institute of Physical Sciences in Medicine (Ipsm) Amendments issued since publication Amd. No. Date CommentsBSEN61262-3:1995 BSI 01-2000 i Contents Page Committees responsible Inside front cover National forewor

5、d ii Foreword 2 Text of EN 61262-3 3 List of references Inside back coverBSEN61262-3:1995 ii BSI 01-2000 National foreword This BritishStandard has been prepared by Technical Committee HCC/72 and is the English language version of EN61262-3:1994 Medical electrical equipment Characteristics of electr

6、o-optical X-ray image intensifiers Part3 Determination of the luminance distribution and luminance non-uniformity, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC1262-3:1994 published by the International Electrotechnical Commission (IEC).

7、 It supersedes BS6251:1982, which is withdrawn. Additional information. The following print types are used in this standard. Requirements, with which compliance can be tested, and definitions: inromantype. Explanations, advice, general statements, exceptions and references: insmaller type. Test proc

8、edures: in italic type Terms defined in clause3 of this standard and in Annex A: in SMALL CAPITALS. For the purposes of this BritishStandard, any references to IEC page numbers in the text should be ignored. A British Standard does not purport to include all the necessary provisions of a contract. U

9、sers of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding BritishStandard HD501S1 (IEC788:1984) BS6641:1985 Glossary of medical radiolog

10、y terms Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to8, 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 amendm

11、ent table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN61262-3 September1994 ICS 11.040.50 Supersedes HD511S1:1988 Descriptors: Medical electrical equipment, image intensifier, X-ray luminance English version Medical electrical equipmentCharacteristics of electro-opt

12、ical X-ray image intensifiers Part3: Determination of the luminance distribution and luminance non-uniformity (IEC1262-3:1994) Appareils lectromdicaux Caractristiques des intensificateurs lectro-optiques dimage radiologique Partie3: Dtermination de la distribution de luminance et de la non-uniformit

13、 de luminance (CEI1262-3:1994) Medizinische elektrische Gerte Merkmale von elektronenoptischen Rntgenbildverstrkern Teil3: Bestimmung der Leuchtdichteverteilung und der Inhomogenitt der Leuchtdichte (IEC1262-3:1994) This European Standard was approved by CENELEC on1994-07-05. CENELEC members are bou

14、nd 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 C

15、entral Secretariat or to any CENELEC 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 CENELEC member into its own language and notified to the Central Secretariat has the same

16、 status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee f

17、or Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1994 Copyright reserved to CENELEC members Ref. No. EN61262-3:1994EEN61262-3:1994 BSI 01-2000 2 Foreword The t

18、ext of document62B(CO)114, as prepared by Sub-Committee62B: Diagnostic imaging equipment, of IEC Technical Committee62: Electrical equipment in medical practice, was submitted to the IEC-CENELEC parallel vote in January1994. the reference document was approved by CENELEC as EN61262-3 on5July1994. Th

19、is European Standard replaces HD511S1:1988. The following dates were fixed: For products which have complied with HD511S1:1989 before1995-07-01, as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until2000-07-01. Annexes designated “n

20、ormative” are part of the body of the standard. Annexes designated “informative” are given only for information. In this standard, Annex A and Annex B are informative and Annex ZA is normative. Contents Page Foreword 2 Introduction 3 1 Scope 3 2 Normative reference 3 3 Terminology 3 3.1 Definitions

21、3 3.2 Degree of requirements and reading instructions 4 4 Requirements 4 4.1 Test set-up 4 4.2 X-RAY IMAGE INTENSIFIER Operatingconditions 4 4.3 Input radiation 4 4.4 TEST DEVICE 4 4.5 Measurement equipment 5 5 Determination of the LUMINANCE DISTRIBUTION and LUMINANCE NON-UNIFORMITY 5 5.1 Preparatio

22、n 5 5.2 Measurement 5 5.3 Corrections 6 5.4 Determination 6 6 Presentation of results 6 6.1 Presentation of the LUMINANCE DISTRIBUTION 6 6.2 Presentation of the LUMINANCE NON-UNIFORMITY 6 7 Statement of compliance 6 Annex A (informative) Terminology Indexofterms 7 Annex ZA (normative) Other internat

23、ional publications quoted in this standard with thereferences of the relevant European publications 8 latest date of publication of an identical national standard (dop)1995-07-01 latest date of withdrawal of conflicting national standards (dow)1995-07-01EN61262-3:1994 BSI 01-2000 3 Introduction The

24、LUMINANCE DISTRIBUTION and LUMINANCE NON-UNIFORMITY of ELECTRO-OPTICAL X-RAY IMAGE INTENSIFIERS are determined from the measurements of the luminance over the area of the OUTPUT IMAGE related to conditions of uniform x-IRRADIATION in the ENTRANCE PLANE of the X-RAY IMAGE INTENSIFIER. The method is i

25、ntended for evaluating relatively large-scale non-uniformity only. More local non-uniformities, such as “structure mottle”, are not considered in this standard. 1 Scope This International Standard applies to ELECTRO-OPTICAL X-RAY IMAGE INTENSIFIERS for medical use, as components of diagnostic X-RAY

26、EQUIPMENT. This International Standard describes a method of determining the LUMINANCE DISTRIBUTION and LUMINANCE NON-UNIFORMITY of X-RAY IMAGE INTENSIFIERS related to conditions of uniform X-IRRADIATION in the ENTRANCE PLANE. 2 Normative reference The following standard contains provisions which, t

27、hrough reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of app

28、lying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC788:1984, Medical Radiology Terminology. 3 Terminology 3.1 Definitions For the purposes of this International Standard, the following definitions ap

29、ply together with those given in IEC788. The definitions given below take preference over those given in IEC788 when differences occur. 3.1.1 XRII an abbreviation for ELECTRO-OPTICAL X-RAY IMAGE INTENSIFIER 3.1.2 ENTRANCE PLANE the plane perpendicular to the axis of symmetry of the XRII and grazing

30、the part of the XRII, including its housing, that protrudes most in the direction of the RADIATION SOURCE 3.1.3 ENTRANCE FIELD for an XRII, the area in the ENTRANCE PLANE that can be used for the transmission of an X-RAY PATTERN under specific conditions 3.1.4 ENTRANCE FIELD SIZE for an XRII, the di

31、ameter of the field in the ENTRANCE PLANE that can be used at a specified SED for the transmission of an X-RAY PATTERN. For an XRII with more than one magnification mode, the ENTRANCE FIELD SIZE for each of the magnification modes shall correspond to the same diameter of the XRII OUTPUT IMAGE occurr

32、ing with the largest ENTRANCE FIELD SIZE 3.1.5 SOURCE TO ENTRANCE PLANE DISTANCE (abbreviation: SED) the distance between the FOCAL SPOT of the X-RAY TUBE and the ENTRANCE PLANE of the XRII 3.1.6 CENTRE OF THE OUTPUT IMAGE the centre of the smallest circle circumscribing the OUTPUT IMAGE 3.1.7 CENTR

33、E OF THE ENTRANCE FIELD that point in the ENTRANCE PLANE which is imaged at the CENTRE OF THE OUTPUT IMAGE 3.1.8 CENTRAL AXIS the line perpendicular to the ENTRANCE PLANE passing through the CENTRE OF THE ENTRANCE FIELD 3.1.9 Not used 3.1.10 LUMINANCE NON-UNIFORMITY for an XRII, the difference of lu

34、minance between the CENTRE OF THE OUTPUT IMAGE and locations near the periphery of the OUTPUT IMAGE under specific conditions, expressed as a percentage of the luminance at the CENTRE OF THE OUTPUT IMAGEEN61262-3:1994 4 BSI 01-2000 3.2 Degree of requirements and reading instructions In this Internat

35、ional Standard the auxiliary verb: and the following words have the meaning: 4 Requirements 4.1 Test set-up a) The SED shall be100cm 1cm. b) The FOCAL SPOT of the X-RAY TUBE shall be on the CENTRAL AXIS. c) The distance between the FOCAL SPOT of the X-RAY TUBE and any ADDED FILTERS shall not exceed3

36、3cm. d) The X-RAY FIELD shall cover the ENTRANCE FIELD entirely, but its area shall not exceed the ENTRANCE FIELD area by more than10%. This limitation of the X-RAY FIELD shall be made by a DIAPHRAGM placed immediately in front of the ENTRANCE PLANE. The BEAM LIMITING DEVICE of the X-RAY SOURCE ASSE

37、MBLY shall be used to limit the X-RAY BEAM on this DIAPHRAGM. The DIAPHRAGM shall provide an ATTENUATION RATIO of at least100 for the quantity AIR KERMA RATE. 4.2 X-RAY IMAGE INTENSIFIER Operating conditions a) The XRII shall be operated under the conditions for NORMAL USE as specified by the manufa

38、cturer. b) No ANTI-SCATTER GRID or protective cover shall be used. c) In the case of multiple-field XRIIs, the measurement shall be made for the largest specified ENTRANCE FIELD. Measurements for other ENTRANCE FIELDS are optional. 4.3 Input radiation a) The TOTAL FILTRATION of the incident X-RAY BE

39、AM shall be22,5mm 0,5mmof aluminium equivalent of which at least20mm is aluminium(99,9%purity). The HALF-VALUE LAYER at the position corresponding to the CENTRE OF THE ENTRANCE FIELD shall be7,0mmAl 0,2mmAl(99,9%purity). This condition corresponds to an approximate X-RAY TUBE VOLTAGE of75kv. b) The

40、AIR KERMA RATE in the ENTRANCE PLANE shall be such that linear operation of the XRII and the detectors employed in the measurement is ensured. An AIR KERMA RATE of14Gy s 1to1004Gys 1is recommended. c) The temporal fluctuations of the AIR KERMA RATE shall not impair the measurement uncertainty by mor

41、e than2%. If the AIR KERMA RATE measurements or the luminance measurements are made at different time instances, the X-RAY TUBE output shall be monitored and the results of the measurements shall be corrected to meet this requirement. d) The AIR KERMA RATE at any location in the ENTRANCE FIELD shall

42、 not be less than70%of the highest value of the AIR KERMA RATE in the ENTRANCE FIELD. 4.4 TEST DEVICE Not used. “shall” implies that compliance with a requirement is mandatory for compliance with the standard; “should” implies that compliance with a requirement is strongly recommended but is not man

43、datory for compliance with the standard; “may” implies that compliance with a requirement is permitted to be accomplished in a particular manner, for compliance with the standard; “specific” when used in combination with parameters or conditions: refers to a particular value or standardized arrangem

44、ent, usually to those required in an IEC standard or a legal requirement; seeIEC788,rm-74-01. “specified” when used in combination with parameters or conditions: refers to a value or arrangement to be chosen for the purpose under consideration and indicated usually in the ACCOMPANYING DOCUMENTS; see

45、IEC788,rm-74-02. “designed for” when used in standards to characterize equipment, devices, components or arrangements: designates an intended and usually apparent purpose or use for the product.EN61262-3:1994 BSI 01-2000 5 4.5 Measurement equipment 4.5.1 Device for measuring the uniformity of the X-

46、RAY FIELD a) Any device measuring a quantity which has a known relationship to the relative AIR KERMA RATE may be used, for example, a photomultiplier tube coupled to a scintillator or a NON-SCREEN FILM with a known sensitometric curve. The device shall have such a precision, that the error of measu

47、ring relative AIR KERMA RATE is2%or less. No particular specifications are required with respect to the absolute accuracy of these measurements. b) The maximum diagonal of the effective measuring area of the device shall not exceed10%of the ENTRANCE FIELD SIZE. 4.5.2 Device for measuring the luminan

48、ce of the OUTPUT SCREEN a) Any device measuring a quantity which has a known relationship to the relative luminance may be used. The device shall have such a precision, that the error of measuring relative luminance is2%or less. No particular specifications are required with respect to the absolute

49、accuracy of these measurements. b) The device shall measure the relative luminance in the direction perpendicular to the plane defined by the OUTPUT SCREEN. The acceptance cone of the detector shall be small enough to avoid errors when measurement approaches a dark edge. c) The diagonal of the effective area of the measuring field shall be at least0,1mm and shall not exceed5%of the OUTPUT IMAGE diameter. d) If the luminance is measured through a lens with a one- or two-dimensional image detector in fixed position, the lens vign