YY 0062-1991 X-ray tube assembly inherent filtration YY0062-1991 standard download decompression password: www.bzxz.net

Pharmaceutical Industry Standard of the People's Republic of China
Inherent Filtration of X-ray Tube Assemblies
This standard is equivalent to the international standard IEC522 (1976) "Inherent Filtration of X-ray Tube Assemblies". 1 Subject content and scope of application
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IEC522-1976
1.1 This standard specifies the concept, definition, expression method and measurement method of the inherent filtration of X-ray tube assemblies and the description of the inherent filtration measured in accordance with this standard.
1.2 This standard is applicable to the determination and expression of the inherent filtration value of X-ray tube assemblies to determine the minimum total filtration of X-ray equipment to protect patients from low-energy ionizing radiation with no clinical value (diagnosis or treatment). This standard is not applicable to measuring the inherent filtration of actual X-ray devices or the total filtration required. 2 Inherent filtration
The filtration produced by the useful beam passing through the materials in the X-ray tube assembly that cannot be removed according to the manufacturer's regulations before it is emitted from the X-ray tube sleeve.
3 Expression method value and reference material
3.1 The inherent filtration value of an X-ray tube assembly operating under specified conditions is expressed as the thickness of a reference material. When this material is placed in a beam of light emitted by an X-ray tube operating under the same specified conditions (tube voltage value and waveform, anode target material and angle) with negligible filtration, the filtered beam has the same initial half-value layer (i.e., mass equivalent filtration) as the beam emitted by the X-ray tube assembly under consideration. 3.2 The inherent filtration must be expressed in the following way. 3.2.1 When the X-ray tube window and the X-ray tube cover window are basically composed of beryllium or other weakly filtered materials, it is expressed as the thickness of beryllium or other materials.
3.2.2 When the X-ray tube assembly operates at a tube voltage below 200kV, it is expressed as the thickness of aluminum. 3.2.3 When the X-ray tube assembly operates at a tube voltage of 150 to 400kV, it is expressed as the thickness of copper. 3.2.4 The indicated value of the inherent filtration must be less than or equal to the measured value and should be within the range of 85% to 100% of the measured value. 3.2.5 The thickness of the reference material must be expressed in millimeters, the reference material in chemical symbols, and the tube voltage in kilovolts. 4 Measurements
4.1 The determination of the inherent filtration must be made by measuring the initial half-value layer on the central axis of the beam and an X-ray tube with a beryllium window (or other material window with negligible filtration) of the same target material and target angle. The half-value layer of radiation emitted when operating under the same tube voltage value and waveform and the same tube current conditions is compared.
4.2 Unless otherwise specified, the measurement must be made at half the maximum tube voltage. 4.3 If there is no X-ray tube with the same target angle, the X-ray tube can be tilted to adjust the radiation beam to the same target angle. 4. It is feasible to measure the filtration of the non-removable material that constitutes the X-ray tube housing through which the useful beam passes, but this requires the provision of substitute materials or the destruction of the X-ray tube to obtain the component. 5 Statement of conformity to this standard
If the determination and expression of the inherent filtration value is to be stated in conformity with this standard, the inherent filtration shall be stated as follows. 5.1 When the value is marked on the X-ray tube assembly with a numerical value and a symbol, the value is given without the unit (millimeters and kilovolts). 5.2 If the marking on the X-ray tube assembly indicates the maximum voltage, it is not necessary to specify one-half of the maximum voltage at which the inherent filtration was determined.
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5.3 Statement of conformity to this standard shall be consistent with the following example. 5.3.1 In the accompanying documents:
IEC522/1976
Inherent filtration 1.2mm Al/ 75kV
5.3.2 In the tube assembly according to this standard: When measuring at half the maximum tube voltage, 1.2Cu IEC 522/1976;
When measuring at other tube voltages, such as 80kV: 1.0A1/ 80 IEC 522/1976.
Additional remarks:
This standard is under the jurisdiction of the National Technical Committee for Standardization of Medical X-ray Equipment and Appliances. This standard was drafted by Shanghai Medical Equipment Factory No. 9. 102
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