BS-EN-61262-2-1995 IEC-61262-2-1994.pdf

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 Standard Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 61262-2:1995 This British Standard, having been prepared under the direction of the Health and Environment Sector Board (H/-), was published under the authority of the Standards Board and comes into effect on 15 March 1995 © BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference HCC/72 Draft for 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 Ltd.) British Institute of Radiology College of Radiographers Institute of Physical Sciences in Medicine (Ipsm) Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 61262-2:1995 © BSI 11-1999i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN 61262-23 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 61262-2:1995 ii © BSI 11-1999 National foreword This British Standard has been prepared by Technical Committee HCC/72 and is the English language version of EN 61262-2:1994 Medical electrical equipment Characteristics of electro-optical X-ray image intensifiers 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 It supersedes BS 6252:1982, which is withdrawn. Additional 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 clause 3 of this standard and in Annex 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 correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred toCorresponding British Standard HD 501 S1 (IEC 788:1984) BS 6641:1985 Glossary of medical radiology terms Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, 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. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 61262-2 September 1994 ICS 11.040.50Supersedes HD 512 S1:1989 Descriptors: Medical electrical equipment, image intensifier, X-ray, conversion factor English version Medical electrical equipment Characteristics of electro-optical X-ray image intensifiers Part 2: Determination of the conversion factor (IEC 1262-2:1994) Appareils électromédicaux Caractéristiques des intensificateurs électro-optiques dimage radiologique Partie 2: Détermination du facteur de conversion (CEI 1262-2:1994) Medizinische elektrische Geräte Merkmale von elektronenoptischen Röntgenbildverstärkern Teil 2: Bestimmung des Konversionsfaktors (IEC 1262-2:1994) This European Standard was approved by CENELEC on 1994-07-05. 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 alteration. 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 by 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, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels © 1994 Copyright reserved to CENELEC members Ref. No. EN 61262-2:1994 E Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 61262-2:1994 © BSI 11-1999 2 Foreword The text of document 62B(CO)113, as prepared by Sub-Committee 62B: Diagnostic imaging equipment, of IEC Technical Committee 62: Electrical equipment in medical practice, was submitted to the IEC-CENELEC parallel vote in January 1994. The reference document was approved by CENELEC as EN 61262-2 on 5 July 1994. This European Standard replaces HD 512 S1:1989. The following dates were fixed: For products which have complied with HD 512 S1:1989 before 1995-07-01, as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until 2000-07-01. Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given only for information. In this standard, Annex A and Annex B are informative and Annex ZA is normative. Contents Page Foreword2 1Scope3 2Normative reference3 3Terminology3 3.1 Definitions3 3.2 Degree of requirements and reading instructions3 4Requirements4 4.1 Test set-up4 4.2 X-RAY IMAGE INTENSIFIER Operating conditions4 4.3 Input radiation4 4.4 TEST DEVICE4 4.5 Measurement equipment4 5Determination of the CONVERSION FACTOR5 5.1 Preparation5 5.2 Measurement5 5.3 Corrections5 5.4 Determination5 6Presentation of the CONVERSION FACTOR5 7Statement of compliance5 Annex A (informative) Terminology Index of terms6 Annex B (informative) Bibliography7 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications7 latest date of publication of an identical national standard(dop) 1995-07-01 latest date of withdrawal of conflicting national standards(dow) 1995-07-01 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 61262-2:1994 © BSI 11-19993 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 only 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 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 applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 788:1984, Medical Radiology Terminology. 3 Terminology 3.1 Definitions For the purposes of this International Standard, the following definitions apply together with those given in IEC 788. The definitions given below take preference over those given in IEC 788 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 the part of the XRII, including its housing, that protrudes most in the direction of theRADIATION 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 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 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 occuring 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 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 perpendicular 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 requirements and reading instructions In this International Standard 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 the standard; “may”implies that compliance with a requirement is permitted to be accomplished in a particular manner, for compliance with the standard; Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 61262-2:1994 4 © BSI 11-1999 and the following words have the meaning: 4 Requirements 4.1 Test set-up a) The SED shall be 100 cm ± 1 cm. 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 exceed 33 cm. d) The X-RAY FIELD shall cover the ENTRANCE FIELD entirely, but its area shall not exceed the ENTRANCE FIELD area by more than 10 %. 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 ASSEMBLY shall be used to limit the X-RAY BEAM on this DIAPHRAGM. The DIAPHRAGM shall provide an ATTENUATION RATIO of at least 100 for the quantity AIR KERMA RATE. 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 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 BEAM shall be 22,5 mm ± 0,5 mm of aluminium equivalent of which at least 20 mm is aluminium (99,9 % purity). The HALF-VALUE LAYER at the position corresponding to the CENTRE OF THE ENTRANCE FIELD shall be 7,0 mm Al ± 0,2 mm Al (99,9 % purity). This condition corresponds to an approximate X-RAY TUBE VOLTAGE of 75 kV. b) The 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 of 1 4Gy s1 to 100 4GY s1 is recommended. c) The temporal fluctuations of the AIR KERMA RATE shall not impair the measurement accuracy by more than 2 %. As the AIR KERMA RATE 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 than 70 % of the highest 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 within ± 5 %. 4.5.2 Device for measuring the luminance of the OUTPUT SCREEN a) The device shall measure the luminance in the direction perpendicular to the plane defined by the OUTPUT SCREEN. If the angular distribution of the luminance deviates by more than 25 % from Lamberts law within a range of 0° up to 30° with respect to the perpendicular of the OUTPUT IMAGE, the measurement should be carried out with an acceptance angle 5° maximum and its variation as a function of the angle should be given. b) The device shall be accurate to within ± 5 %. “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 legal requirement; see IEC 788, 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 IEC 788, 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. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 08 02:39:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 61262-2:1994 © BSI 11-19995 c) The instrument shall have a spectral sensitivity corresponding to the standardized curve V2 of the human eye under photopic conditions. 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 in 4.1 shall be fulfilled. b) The TOTAL FILTRATION of the RADIATION BEAM and the X-RAY TUBE VOLTAGE are adjusted according to 4.3 a) to obtain the required HALF-VALUE LAYER at the position corresponding to the CENTRE OF THE ENTRANCE FIELD according to 4.1. 5.2 M