JB/T 7902-1999 This standard adopts the international standard ISO 1027:1983 "Rules and markings for radiographic image quality indicators for non-destructive testing" and is a revision of JB/T 7902-95 "Linear image quality indicators". During the revision, only editorial changes were made according to relevant regulations, and the technical content remained unchanged. This standard specifies the manufacturing technology, marking and related application methods of linear image quality indicators (hereinafter referred to as image quality indicators). The image quality indicators are used to measure the image quality of x-ray or gamma-ray photography of metal materials. When the image quality indicators specified in this standard cannot meet the use requirements, a corresponding special image quality indicator can be designed separately. This standard was first issued as GB 5618-85 on November 25, 1985, and was adjusted to JB/T 7902-95 in April 1996. JB/T 7902-1999 Linear Image Quality Meter JB/T7902-1999 Standard download decompression password: www.bzxz.net

JB/T7902--1999
This standard is a revision of JB/T7902-95 (formerly GB5618-85) "Linear Image Quality Indicator" based on the international standard ISO1027--1983 "Rules and Markings for Radiographic Image Quality Indicators for Nondestructive Testing" which is not equivalent. This revision only makes editorial changes, and the technical content remains unchanged.
This standard replaces JB/T7902-95 from the date of implementation. Appendix A of this standard is the appendix of the standard. This standard is proposed and managed by the National Technical Committee for Welding Standardization. The drafting units of this standard are: Harbin Welding Research Institute, Shanghai Flaw Detection Machine Factory, Harbin Welding Technology Training Center. The main drafters of this standard are Sun Liwei, Qin Xinghua, Jie Yinglong, and Chen Yu. This standard was first published in 1985, and this revision is the first revision. 343
1 Scope
Standard of the Machinery Industry of the People's Republic of ChinabZxz.net
Wire type image quality indicator
Wire type image quality indicatorJB/T 7902—1999
Replacement JB/T7902--95
This standard specifies the manufacturing technical requirements, marking and relevant application methods of the wire type image quality indicator (hereinafter referred to as the image quality indicator). The image quality indicator is used to measure the image quality of X-ray or radiographic photography of metal materials. When the image quality indicator specified in this standard cannot meet the use requirements, a corresponding special image quality indicator can be designed separately.
2 Technical requirements
2.1 The image quality indicator is composed of metal wires of different diameters. The diameter of the wire is selected according to the two rounded value series of R'10 and R'20. The wire diameter, its allowable deviation and wire number are listed in Table 1.
Table 1 Wire diameter and its allowable deviation and wire number R'10 series
Allowable deviation
Wire number
R'20 series
Allowable deviation
Wire number
2.2 Seven metal wires connected by numbers are grouped into two categories and six groups. That is, the R'10 series has three groups: 1 to 7; 6 to 12; 10 to 16, and the R'20 series has three groups: (1) to (7); (6) to (12); (10) to (16), see Table 2. Approved by the State Bureau of Machinery Industry on June 24, 1999 344
2000-01-01 Selling and applying
Wire diameter
JB/T 7902—1999
R'10 series
Image quality meter group
(1)~(7)
2.3 The metal wires shall be arranged parallel to each other, and their lengths shall not be less than 25mm and 50mrh respectively. 2.4 The spacing between the axes of the metal wires shall not be less than 3 times the diameter of the thicker wire, but shall be a minimum of 5mm. R'20 series
(6)~(12)
(10)~(16)
2.5 All metal wires in each image quality meter shall be made of the same material and fixed in a sheath made of a weakly absorbing material (in principle, without affecting the image quality).
2.6 The markings of the image quality indicator shall be clear and complete and can be clearly displayed on the radiographic film. 3 Markings and codes
3.1 The image quality indicator shall have the following markings:
Image quality indicator standard number: JB/T7902-1999Wire material code: FECU: AL, etc.
The numbers of the thickest and thinnest lines are shown in Table 3:
R'10 series
R20 series
1+7,612,10:16
(1)+(7):(6)+(12);(10)+(16)
Note: The number of the thickest line is on the side of the thickest line, and the number of the thinnest line is on the side of the thinnest line. 3.2 Example of IQI Code
indicates a linear IQI composed of carbon steel wires numbered 10 to 16 with different diameters: IQI FE10/16JB/T7902-1999
An example of an IQI is shown in Figure 1:
JB/T 7902-1999
4 Sample drawings of applicable materials for image quality meters and methods of expressing image quality 4.1 The applicable material range of the image quality meter is shown in Table 4. 345
Image quality meter wire code
Wire material
Applicable material range
JB/T79.02—19.99
Table 4 Applicable material range of image quality meters for different wires FE
Carbon pot
Black gold
Copper, zinc, tin and tantalum alloy
4.2 When using the image quality meter specified in this standard, the sensitivity K of radiography is calculated according to formula (1): K=d/TX100%
Where: K————Radiographic sensitivity expressed as a percentage: penetration thickness of the workpiece to be inspected, mm,
d——diameter of the thinnest line that can be identified on the radiographic film, mm. AL
Aluminum and aluminum alloys
The size obtained by using the image quality meter is only used to measure the quality of the radiographic image, and cannot directly indicate the actual size that can be found to be self-adjusted.
JB/T7902-1999
Appendix A
(Difficult Appendix)
The sensitivity range that can be expressed by the linear image quality meter The sensitivity range that can be expressed by the linear image quality meter is shown in Table A1. Table A1 | |tt | t | 63
(6)(12)
0. 9~1. 8
0.72-1. 44
0. 6~1.2
0. 51 ~~1. 03
(1)-~(7)
1.28-2.52
1. 07~ 2. 1
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