1、BRITISH STANDARD BS EN 61262-2:1995 IEC 1262-2: 1994 Characteristics of electro-optical X-ray image intensifiers for medical electrical equipment Part 2: Determination of the conversion factor The European Standard EN 61262-2:1994 has the status of a British StandardBSEN61262-2:1995 This British Sta
2、ndard, having been prepared under the directionof the Health and Environment Sector Board (H/-),was published under the authority of the Standards Boardand comes intoeffect on 15March1995 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference HCC/72 Draft f
3、or comment 94/501342 DC ISBN 0 580 23591 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee HCC/72, Image intensifiers, upon which the following bodies were represented: Association of X-ray Equipment Manufacturers (BEAMA
4、Ltd.) British Institute of Radiology College of Radiographers Institute of Physical Sciences in Medicine (Ipsm) Amendments issued since publication Amd. No. Date CommentsBSEN61262-2:1995 BSI 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN
5、61262-2 3 List of references Inside back coverBSEN61262-2:1995 ii BSI 11-1999 National foreword This British Standard has been prepared by Technical CommitteeHCC/72 and is the English language version ofEN61262-2:1994 Medical electrical equipment Characteristics of electro-optical X-ray image intens
6、ifiers Part 2: Determination of the conversion factor, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 1262-2:1994 published by the International Electrotechnical Commission (IEC). It supersedes BS6252:1982, which is withdrawn. Additional
7、information. The following print types are used in this standard. Requirements, with which compliance can be tested, and definitions: in roman type. Explanations, advice, general statements, exceptions and references: in smaller type. Test procedures: in italic type Terms defined in clause3 of this
8、standard and inAnnex A: in SMALL CAPITALS. For the purposes of this British Standard, 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. Users of British Standards are responsible for their corr
9、ect application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard HD 501 S1 (IEC788:1984) BS 6641:1985 Glossary of medical radiology terms Summary of pages This document comprises a f
10、ront cover, an inside front cover, pagesi andii, theEN title page, pages2to8, 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 amendment table on the inside front cover.EUROPEAN STANDARD
11、 NORME EUROPENNE EUROPISCHE NORM EN 61262-2 September 1994 ICS 11.040.50 SupersedesHD512S1:1989 Descriptors: Medical electrical equipment, image intensifier, X-ray, conversion factor English version Medical electrical equipment Characteristics of electro-optical X-ray image intensifiers Part2:Determ
12、ination of the conversion factor (IEC 1262-2:1994) Appareils lectromdicaux Caractristiques des intensificateurs lectro-optiques dimage radiologique Partie2:Dterminationdufacteurde conversion (CEI1262-2:1994) Medizinische elektrische Gerte Merkmale von elektronenoptischen Rntgenbildverstrkern Teil2:B
13、estimmungdes Konversionsfaktors (IEC1262-2:1994) This European Standard was approved by CENELEC on1994-07-05. CENELEC members are bound 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 a
14、lteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made b
15、y translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland,
16、 Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stass
17、art 35, B-1050 Brussels 1994 Copyright reserved to CENELEC members Ref. No. EN 61262-2:1994EEN61262-2:1994 BSI 11-1999 2 Foreword The text of document62B(CO)113, as prepared by Sub-Committee62B: Diagnostic imaging equipment, of IEC Technical Committee62: Electrical equipment in medical practice, was
18、 submitted to the IEC-CENELEC parallel vote in January1994. The reference document was approved by CENELEC as EN61262-2 on5July1994. This European Standard replaces HD512S1:1989. The following dates were fixed: For products which have complied withHD512S1:1989 before1995-07-01, as shown by the manuf
19、acturer or by a certification body, this previous standard may continue to apply for production until2000-07-01. Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given only for information. In this standard, Annex A andAnnex B are informative
20、andAnnex ZA is normative. Contents Page Foreword 2 1 Scope 3 2 Normative reference 3 3 Terminology 3 3.1 Definitions 3 3.2 Degree of requirements and reading instructions 3 4 Requirements 4 4.1 Test set-up 4 4.2 X-RAY IMAGE INTENSIFIER Operating conditions 4 4.3 Input radiation 4 4.4 TEST DEVICE 4 4
21、.5 Measurement equipment 4 5 Determination of the CONVERSION FACTOR 5 5.1 Preparation 5 5.2 Measurement 5 5.3 Corrections 5 5.4 Determination 5 6 Presentation of the CONVERSION FACTOR 5 7 Statement of compliance 5 Annex A (informative) Terminology Index of terms 6 Annex B (informative) Bibliography
22、7 Annex ZA (normative) Other international publications quoted in this standard with thereferences of the relevant European publications 7 latest date of publication ofan identical national standard (dop)1995-07-01 latest date of withdrawal ofconflicting national standards (dow)1995-07-01EN61262-2:1
23、994 BSI 11-1999 3 1 Scope This International Standard applies to ELECTRO-OPTICAL X-RAY IMAGE INTENSIFIERS for medical use, as components of diagnostic X-RAY EQUIPMENT. This International Standard describes a method of determining the CONVERSION FACTOR of X-RAY IMAGE INTENSIFIERS. It is applicable on
24、ly to devices whose output light spectra do not significantly deviate from that of a P-20 phosphor. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this InternationalStandard. At the time of publication, the edition ind
25、icated was valid. All standards are subject to revision, and parties to agreements based on this InternationalStandard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid Inter
26、nationalStandards. IEC 788:1984, Medical Radiology Terminology. 3 Terminology 3.1 Definitions For the purposes of this InternationalStandard, the following definitions apply together with those given in IEC788. The definitions given below take preference over those given in IEC788 when differences o
27、ccur. 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 theXRII and grazing the part of theXRII, including its housing, that protrudes most in the direction of theRADIATION SOURCE 3.1.3 ENTRANCE FIELD for an
28、 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 diameter of the field in the ENTRANCE PLANE that can be used at a specified SED for the transmission of an X-RAY PATTERN. For anXRII wi
29、th more than one magnification mode, the ENTRANCE FIELD SIZE for each of the magnification modes shall correspond to the same diameter of theXRII OUTPUT IMAGE occuring with the largest ENTRANCE FIELD SIZE 3.1.5 SOURCE TO ENTRANCE PLANE DISTANCE (abbreviation: SED) the distance between the FOCAL SPOT
30、 of the X-RAY TUBE and the ENTRANCE PLANE of theXRII 3.1.6 CENTRE OF THE OUTPUT IMAGE the centre of the smallest circle circumscribing the OUTPUT IMAGE 3.1.7 CENTRE 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 pe
31、rpendicular to the ENTRANCE PLANE passing through the CENTRE OF THE ENTRANCE FIELD 3.1.9 Not used 3.1.10 CONVERSION FACTOR the ratio of the luminance in the CENTRE OF THE OUTPUT IMAGE of a specific zone in the OUTPUT IMAGE to the AIR KERMA RATE in the CENTRE OF THE ENTRANCE FIELD 3.2 Degree of requi
32、rements and reading instructions In this InternationalStandard the auxiliary verb: “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 mandatory for compliance with th
33、e standard; “may” implies that compliance with a requirement is permitted to be accomplished in a particular manner, for compliance with the standard;EN61262-2:1994 4 BSI 11-1999 and the following words have the meaning: 4 Requirements 4.1 Test set-up a) The SED shall be100cm 1cm. b) The FOCAL SPOT
34、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 exceed33cm. 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 t
35、he 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 ASSEMBLY 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 RAT
36、E. e) The CONVERSION FACTOR varies with temperature and the measurements shall refer to normal room temperatures (i.e.23 C 3 C). 4.2 X-RAY IMAGE INTENSIFIER Operating conditions a) The XRII shall be operated under the conditions for NORMAL USE as specified by the manufacturer. b) No ANTI-SCATTER GRI
37、D 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 BEAM shall be22,5mm 0,5mm of alu
38、minium 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 AIR KERMA RATE in the ENTR
39、ANCE PLANE shall be such that linear operation of the XRII and the detectors employed in the measurement is ensured. An AIR KERMA RATE of14Gys 1to1004GYs 1is recommended. c) The temporal fluctuations of the AIR KERMA RATE shall not impair the measurement accuracy by more than2%. As the AIR KERMA RAT
40、E measurements and 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 not be less than70% of the h
41、ighest value of the AIR KERMA RATE in the ENTRANCE FIELD. 4.4 TEST DEVICE Not used. 4.5 Measurement equipment 4.5.1 Device for measuring the AIR KERMA RATE The device shall be accurate to within5%. 4.5.2 Device for measuring the luminance of the OUTPUT SCREEN a) The device shall measure the luminanc
42、e in the direction perpendicular to the plane defined by the OUTPUT SCREEN. If the angular distribution of the luminance deviates by more than25% from Lamberts law within a range of0 up to30 with respect to the perpendicular of the OUTPUT IMAGE, the measurement should be carried out with an acceptan
43、ce angle5 maximum and its variation as a function of the angle should be given. b) The device shall be accurate to within5%. “specific” when used in combination with parameters or conditions: refers to a particular value or standardized arrangement, usually to those required in an IEC standard or a
44、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; seeIEC788, rm-74-02. “designed for” when used in standard
45、s to characterize equipment, devices, components or arrangements: designates an intended and usually apparent purpose or use for the product.EN61262-2:1994 BSI 11-1999 5 c) The instrument shall have a spectral sensitivity corresponding to the standardized curve V 2of the human eye under photopic con
46、ditions. See: CIE Publication No.15(1971), Colorimetry, International Commission on Illumination. 5 Determination of the CONVERSION FACTOR 5.1 Preparation a) The requirements for the measurement set-up given in4.1 shall be fulfilled. b) The TOTAL FILTRATION of the RADIATION BEAM and the X-RAY TUBE V
47、OLTAGE are adjusted according to4.3 a) to obtain the required HALF-VALUE LAYER at the position corresponding to the CENTRE OF THE ENTRANCE FIELD according to4.1. 5.2 Measurement 5.2.1 Measurement of the AIR KERMA RATE a) After the determination of the ENTRANCE PLANE and the CENTRE OF THE ENTRANCE FI
48、ELD, theXRII is removed from the beam. No objects capable of scattering X-RADIATION shall remain in the X-RAY BEAM at a distance less than 50cm from theENTRANCE PLANE according to4.1. b) The measuring device shall be positioned such that its sensitive area is located in the ENTRANCE PLANE and centre
49、d around theCENTRE OF THE ENTRANCE FIELD. NOTEFor thick detectors the REFERENCE POINT as defined inIEC731 should be placed at the CENTRE OF THE ENTRANCE FIELD. c) The sensitive area of the measuring device shall be such that the uniformity of the AIR KERMA RATE inside that area is better than3%. d) If the indication of the measuring device depends on the air-pressure, the measuring results shall be corrected accordingly. 5.2.2 Measurement of the OUTPUT SCREEN luminance a) The XRII shall be positioned as stated i
