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GB/T 23901.5-2019 English PDF (GBT23901.5-2019)

GB/T 23901.5-2019 English PDF (GBT23901.5-2019)

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GB/T 23901.5-2019: Non-destructive testing -- Image quality of radiographs -- Part 5: Determination of the image quality unsharpness and basic spatial resolution value using duplex wire-type image quality indicators

GB/T 23901.5-2019
Non-destructive testing--Image quality of radiographs--Part 5. Determination of the image quality unsharpness and basic spatial resolution value using duplex wire-type image quality indicators ICS 19.100
J04
National Standards of People's Republic of China
Replace GB/T 23901.5-2009
Non-destructive testing radiographic inspection image quality
Part 5. Double-wire image quality image
Determination of unsharpness
Part 5.Determinationoftheimagequalityunsharpnessandbasicspatial
(ISO 19232-5.2018, IDT)
2019-06-04 released 2020-01-01 implementation
State market supervision and administration
China National Standardization Administration issued
Content
Foreword I
1 range 1
2 Normative references 1
3 Terms and Definitions 1
4 Double wire image quality specification 2
5 use of double wire type image quality instrument 4
6 High resolution image quality meter with larger measurement range 7
7 record 9
8 Accuracy and deviation 9
Reference 10
Foreword
GB/T 23901 "Non-destructive testing radiographic inspection image quality" is divided into five parts. ---Part 1. Determination of the image quality of the silk-type image quality meter; --- Part 2. Determination of image quality values of stepped hole image quality meters; --- Part 3. Image quality classification;
--- Part 4. Experimental evaluation of image quality and image quality table; --- Part 5. Determination of image clarity of double-filament image quality. This part is the fifth part of GB/T 23901.
This part is drafted in accordance with the rules given in GB/T 1.1-2009. This part replaces GB/T 23901.5-2009 "Non-destructive testing of radiographic film quality - Part 5. Two-line image quality Like the determination of unsharpness, compared with GB/T 23901.5-2009, the main changes are as follows. --- Revised the normative reference document (see Chapter 2, Chapter 2 of the.2009 edition); ---Modified terms and definitions (see Chapter 3, Chapter 3 of the.2009 edition); ---" Radiographic film quality" was changed to "radiography to detect image quality"; --- "film" changed to "detector";
--- "Linear image quality meter" was changed to "wire type image quality meter"; --- Modified the writing order of the double-wire type image quality meter number (see 4.1.3); --- Added high resolution twin wire image quality meter (see Chapter 6); --- Expanded the narrative of the dual-wire image quality application (see Chapters 5 and 6). This section uses the translation method equivalent to ISO 19232-5.2018 "Non-destructive testing radiographic inspection image quality Part 5. Double Determination of the unsharpness of the silk image quality image.
The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows. ---GB/T 12604.2-2005 Non-destructive testing term radiographic testing (ISO 5576.1997, IDT) --- GB/T 27050.1-2006 Conformity assessment supplier's declaration of conformance Part 1. General requirements (ISO /IEC 17050- 1.2004, IDT)
This part is proposed and managed by the National Non-Destructive Testing Standardization Technical Committee (SAC/TC56). This section drafted by. Shanghai Aerospace Power Technology Engineering Co., Ltd., Shanghai Space Propulsion Research Institute, Shanghai Materials Research Institute, Hubei III Jiang Aerospace Jiangbei Mechanical Engineering Co., Ltd., Zhejiang Jinyun Image Quality Meter Factory, Matrix Science and Technology Testing Technology (Beijing) Co., Ltd., China Guangdong Nuclear Power Engineering Co., Ltd., Sichuan Aerospace Chuanan Fire Technology Co., Ltd., Shanghai Aerospace Precision Machinery Research Institute, Shanghai Aerospace Equipment Manufacturing Plant Co., Ltd. Division, Shanghai Satellite Equipment Research Institute, Institute of Acoustics, Chinese Academy of Sciences, Donghai Research Station, Zhejiang Special Equipment Inspection and Research Institute, Shanghai Feitianzhong Zhi Technology Co., Ltd., Aerospace Materials and Technology Research Institute, CITIC Daika Co., Ltd., Ningbo Special Equipment Inspection and Research Institute, Shanghai Airlines Tiantian Control Technology Research Institute, Aintik Testing Technology (Shanghai) Co., Ltd. The main drafters of this section. Xu Guozhen, Chen Yiwei, Lu Yanda, Jiang Jiansheng, Ding Jie, Wang Xiaoyong, Liu Zhanglong, Jiang Yunxi, Zhu Congbin, Zhang Zheng, Zhou Jianping, Wei Wei, Xu Wei, Sun Jianwei, Hu Ling, Huang Wenda, Wang Daolong, Yuan Life, Liu Jun, Chen Hu, Yuan Zhizuo, Zhang Rui, Zhang Yifeng, Yan Lianna, Ma Jun.
The previous versions of the standards replaced by this section are.
---GB/T 23901.5-2009.
Non-destructive testing radiographic inspection image quality
Part 5. Double-wire image quality image
Determination of unsharpness
1 Scope
This part of GB/T 23901 specifies the method for determining the unsharpness and spatial resolution of radiographic images. The two-wire type image quality meter for the 13 pairs of wire pairs specified in this section can be used up to 600kV, and more than 13 pairs of wire pairs The tube voltage range for the image quality meter is less than 225kV. When using high-energy radiographic detection of more than 1 MeV, refer to the use of this part. The split wire type image quality meter, but the measurement results may have large deviations. 2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article. Pieces. For undated references, the latest edition (including all amendments) applies to this document. ISO 5576 non-destructive testing ray detection terminology (Non-destructive testing-IndustrialX-rayandgamma- rayradiology-Vocabulary)
ISO /IEC 17050-1 Conformity Assessment Suppliers - Conformity Assessment Part 1. General (Conformityassessment- Supplier'sdeclarationofconformity-Part 1.Generalrequirements)
3 Terms and definitions
The following terms and definitions as defined by ISO 5576 apply to this document. 3.1
Double wire image quality detector duplexwire-typeimagequalityindicator Double wire type IQI
An image quality meter consisting of a series of pairs of high density wires for determining the unsharpness and spatial resolution of radiographic images. 3.2
Total undefinition image totalimageunsharpnessvalue
UT
The value is equal to the sum of the wire diameter and the wire pitch of the pair, and the pair of the smallest numbered pairs of the spaced double-wire type image quality meter cannot be effectively identified. Note 1. The corresponding unsharpness values are shown in Table 1.
Note 2. UT can be UTvisual, UT20% or iUT20%.
3.3
Visually determine the total unsharpness of the image totalimageunsharpnessvaluedeterminedvisualy UTvisual
The line number of the smallest number of the double-wire type image quality meter which cannot recognize the interval was visually observed on the radiographic inspection image. 3.4
Digital image modulation transfer function curve determination image total unsharpness totalimageunsharpnessvaluedeterminedfrom Aprofilefunctioninadigitalimage
UT20%
On the modulation transfer function curve of the digital image, the minimum number of the two-wire type image quality meter whose modulation degree is less than 20% and the interval cannot be recognized Line pair.
3.5
Interpolation method to determine the total unsharpness of the image interpolatedtotalimageunsharpnessvalue iUT20%
The modulation transfer function curve is used to determine the modulation degree of adjacent pairs, and a linearized modulation transfer function curve is obtained, which is interpolated. The method determines the smallest numbered pair of lines on the corresponding digital image when the degree of modulation is 20%. 3.6
Spatial resolution basicspatialresolution
SRb
The value is equal to half of the unsharpness of the radiographic image, and the smallest geometric detail can be identified on the digital image. 3.7
Detector basic spatial resolution basicspatialdetectorresolutionvalue
SRbdetector
Equivalent to half of the detector undefined UTvisual or UT20% measured on the detected image, identifiable when the magnification is equal to 1. The minimum geometric detail of the image is detected, ie the effective pixel size. Note. The double-wire image quality meter is placed directly on the detector surface during the measurement. The value is the smallest numbered line pair that cannot be visually recognized, or is modulated. The hand function curve determines the least numbered line pair whose modulation degree is less than 20% and does not recognize the interval. 3.8
Image spatial resolution basicspatialimagerresolutionvalue
SRbimage
Equivalent to detecting the total unsharpness of the image on the image is UTvisual or half of UT20%, which can be recognized when the magnification is greater than 1. The smallest geometric detail of the detected image, that is, the effective pixel size of the enlarged image. Note. The value of the spatial resolution of the image is the smallest numbered line pair that cannot be visually recognized, or the modulation transfer function curve is used to determine the modulation is less than 20% does not recognize the smallest numbered pair of intervals.
3.9
Interpolation method for determining image spatial resolution interpolatedbasicspatialimageresolutionvalue iSRbimage
It is equivalent to detecting half of the total unsharpness iUT of the image measured on the image, and the detection pattern that can be recognized when the magnification is greater than 1. The minimum geometric detail of the image, ie the effective pixel size of the magnified image as determined by interpolation. Interpolation method for determining the spatial resolution of an image The value is the modulation degree of the adjacent line pair of the two-wire type image quality image using the modulation transfer function curve, and the modulation degree is obtained by interpolation. The pair value corresponding to 20%.
Note. When determining the detector's basic spatial resolution (SRbdetector), the twin-wire image quality meter is placed directly on the detector. The iSRbdetector measured at this time. =iSRbimage.
3.10
Pair value linepairpermmvalue
Lp/mm
The value is equivalent to 1/UT, the value of the double pair or the pair value determined by interpolation. Note. UT can be UTvisual, UT20% or iUT20%, the corresponding line pair values are shown in Table 1. 4 double wire image quality specification
4.1 Image quality composition, manufacturing, marking
4.1.1 Composition
The standard twin-wire image quality meter shall consist of 13 sets of metal wire pairs placed in rigid transparent plastic, each set of pairs containing a pair of circular cuts. The wire of the surface. The material of the D1~D3 pair is tungsten, and the materials of other pairs are platinum. The size of the image quality meter should meet the requirements of Figure 1. The unit is mm
Description.
1---identification mark GB/T 23901.5;
2---Support fixed hard plastic;
d---wire diameter (equal to the line pair spacing).
a wire having a diameter d equal to the line pair spacing;
b A magnified view of a single set of pairs.
Figure 1 Double wire image quality meter
4.1.2 Manufacturing
The diameter and spacing of the wires are shown in Table 1.
Table 1 Pair number, corresponding total unsharpness, spatial resolution, line pair value and wire diameter and its tolerance a Wire material pair number
Corresponding unsharp value
UT/mm
Corresponding spatial resolution b
SRb/mm
Corresponding pair value
Lp/mm
Wire diameter and spacing
d/mm
Wire diameter and spacing limit
Deviation/mm
Ptc D13 0.10 0.050 10.0 0.050
Pt D12 0.13 0.063 7.94 0.063
Pt D11 0.16 0.080 6.25 0.080
Pt D10 0.20 0.100 5.00 0.100
Pt D9 0.26 0.130 3.85 0.130
±0.005
Table 1 (continued)
Wire material pair number
Corresponding unsharp value
UT/mm
Corresponding spatial resolution b
SRb/mm
Corresponding pair value
Lp/mm
Wire diameter and spacing
d/mm
Wire diameter and spacing limit
Deviation/mm
Pt D8 0.32 0.160 3.13 0.16
Pt D7 0.40 0.200 2.50 0.20
Pt D6 0.50 0.250 2.00 0.25
Pt D5 0.64 0.320 1.56 0.32
Pt D4 0.80 0.400 1.25 0.40
±0.01
Wd D3 1.00 0.500 1.00 0.50
W D2 1.26 0.630 0.79 0.63
W D1 1.60 0.800 0.63 0.80
±0.02
a All unsharpness values are rounded to two digits after the decimal point. b If the SRb value unit is μm, the value in mm in the table is multiplied by 1000. c Pt is platinum.
d W is tungsten.
4.1.3 Marking
The two-wire image quality meter should be marked by “GB D” (or GB/T 23901.5) and “serial number”. The marking should be carried out in an appropriate manner. An image quality meter with "END or EN462-5 or ASTME2002 or JISZ2307 or ISO " is equivalent to an image quality meter with "GB " use.
4.2 Quality Assurance
Each image quality meter should be accompanied by a certificate that complies with ISO /IEC 17050-1 or is issued by a qualified laboratory and that complies with this part of the technology. Certificate of conformity for the condition. For ease of identification, manufacturers should also number and mark image quality meters. 5 use of double wire type image quality meter
5.1 General
For radiographic inspection, the double-wire image quality meter should be placed on the source surface of the test object, or the double-wire type image quality meter should be placed on the test object. The test piece is the same material and thickness. In transillumination, the two-wire image quality meter should be as close as possible to the beam axis and perpendicular to the axis. Note. If the two-wire image quality meter is placed directly on the detector, the detector's basic spatial resolution SRbdetector and the detector's inherent unsharpness are measured. The evaluation of the two-wire image quality image is performed by visually measuring the detected image or by modulating the transfer function curve to the digital image. Determination. The total unsharpness of the image UT can be determined by 2d, d is the diameter or spacing of the wire (see Figure 1), and is also the spatial resolution of the image, 1/2d Indicates the pair value.
5.2 Visual determination
When visually measuring the image of the two-wire image quality on the image, the image should be magnified four times. Visual measurement of radiographic film When the D12 and above are paired, a magnifying glass of 2 times or more should be used. When the two wires of the pair in the image do not recognize the gap and merge into a monofilament The corresponding line pair number is determined as the limit of the radiographic detection visual resolution. Visually determining the ability to identify pairs in radiographic inspection images, depending on the contrast-to-noise ratio (CNR) and signal-to-noise of the ray system The ratio (SNR) also depends on the grade of the film system and the tube voltage (kV). 5.3 Determination of digital image modulation transfer function curve
The modulation transfer function curve is used to measure the double-wire image quality timing in the digital image, and the modulation on the modulation transfer function curve is less than 20%. The minimum number of pairs that should be determined is the resolution limit of the digital image. The degree of modulation is measured from the modulation transfer function curve, see figure 2.
The two-wire image quality meter should be placed at an angle of approximately 2° to 5° with the detector pixel rows and columns [see Figure 2a)] to reduce the number of images in the digital image. Aliasing phenomenon.
The total unsharpness or spatial resolution of the digital image is determined by the first set of pairs having a modulation degree of less than 20%. The measurement method should use a wheel of a modulation transfer function curve in the middle of the image of the two-wire type image quality image by the image processing software. The frame is completed, and the middle area refers to 30%~60% of the length of the double wire to obtain a stable repeatable measurement value, and the modulation transfer function curve is The width of the outline frame should be no less than 11 pixels to avoid abnormal data changes along the length of the twin wire, see Figure 2b) and Figure 2c). 5.4 Determination of digital image modulation transfer function curve
In order to more accurately determine the total unsharpness iUT or spatial resolution iSRb of a digital image, interpolation or approximation should be used. Determine the pair value of the modulation degree of 20%. This can be agreed between the manufacturer and the customer. The two-wire image quality meter should be placed at an angle of approximately 2° to 5° with the detector pixel rows and columns [see Figure 2a)] to reduce the number of images in the digital image. Aliasing phenomenon.
The measurement method uses a wheel of a modulation transfer function curve in the middle region of the two-wire type image quality image by image processing software. The frame is completed, and the middle area refers to 30%~60% of the length of the double wire to obtain a stable repeatable measurement value, and the modulation transfer function curve is The width of the outline frame should be no less than 11 pixels to avoid abnormal data changes along the length of the twin wire, see Figure 2a), Figure 2b) and Figure 2c). In order to improve the measurement accuracy of iUT and iSRb values, the modulation degree 20% (dip) value should be approximated from the dip value of adjacent twin wires. Got it. Figure 3 shows the corresponding determination process.
iSRb is calculated by the polynomial approximation of the modulation degree (dip). When the modulation degree is greater than zero, there is at least a modulation transfer function graph. Two adjacent pairs with a modulation degree greater than 20% and two adjacent pairs with a modulation degree less than 20% are shown in FIG. If there is no less than 20% If the system is available, the next set of line pair modulations should be used for zero processing. When the measured iSRb is smaller than the pixel size, consider the aliasing Like, iSRb is considered to be equal to the pixel size.
The total unsharpened iUT determined by interpolation is calculated by equation (1). iUT=2·iSRb (1)
The spatial resolution in the approximate calculation or interpolation method in Fig. 3b) should be recorded as "SRb value determined by interpolation" or iSRb. Approximation The total unsharpness calculated or interpolated shall be recorded as "UT determined by interpolation" or iUT. The resolution of the line pair interval is determined according to the degree of modulation, and should be consistent with the calculation of the second-order polynomial function to determine the intersection point of 20%. The value of the pair spacing is shown in Figure 3b).
5.5 Image quality requirements
The image quality requirements shall be determined by both the supplier and the buyer according to the specific testing requirements, and the requirements or references shall be specified in the relevant technical documents. standard.
5.6 Use of double wire type image quality meter
The two-wire image quality meter can be used to determine the geometric unsharpness Ug, total unsharp UT and spatial resolutio...

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