CN1142609A - Nondestructive testing method and apparatus and its application mobile gamma digital radiation imaging - Google Patents

Abstract

The invention relates to a mobile non-destructive detection method and device for γ-ray digital radiation imaging and its application. The radiation source and its container, front and rear collimators, array detectors, signal and image processing units are fixedly installed on a rigid frame, A driving mechanism installed on the rigid frame or connected to it drives the whole device to scan back and forth, or the rigid frame does not move, and the dragging mechanism drags the object to pass through the irradiation area to scan back and forth, so as to realize the scanning of the object non-destructive testing. The device is used for gamma digital radiation imaging non-destructive testing of large objects such as containers, trucks, trains, missiles, etc., or small objects such as machine parts, castings, forgings, explosives, pressure vessels, etc.

Description

Mobile gamma digital radiation imaging non-destructive testing method and device and application thereof

The present invention relates to a non-destructive testing method and device of γ digital radiation imaging, more specifically, the present invention especially relates to a mobile non-destructive testing method and device of γ digital radiation imaging and its application, which is used for inspecting containers and trucks The internal conditions of objects such as missiles, missiles, and small parts belong to the field of nuclear technology applications.

Existing various types of digital radiographic imaging container detection devices (hereinafter referred to as "detection devices"), as described in the product information of Schlumberger Company of France, Heyman Company of Germany, British Aerospace Corporation and Chinese patent ZL93102728.4, Both use electron accelerators (electrostatic accelerators or linear accelerators) as their high-energy X-ray sources. The equipment is huge, heavy, and has high radiation intensity. They must be fixedly installed and operated in heavy shielding buildings. This type of accelerator-type detection device can meet the requirements of the customs for smuggling, but has the following defects:

① The detection device is a fixed device. When performing scanning detection, there must be a special drag mechanism to make the object to be inspected pass through the irradiation area at a required scanning speed with a certain accuracy. The weight of large container trucks can reach about 50 tons. The dragging mechanism required to be able to accurately and stably drag such a heavy object is very technically difficult and expensive, and is prone to failure, which is often a major weak link affecting the reliability of the overall operation. When the object to be inspected is very long and heavy (such as a whole train of railway wagons), its dragging mechanism will be more difficult to realize.

② The radiation intensity of the accelerator radiation source used in the detection device is very high, and the shielding wall of the main part of the protective building is more than 2 meters thick. In addition, because the high-energy X-radiation produced by the accelerator used is not isotropic, the opening angle of the irradiation field used is generally about 30°. Therefore, in order to make the irradiation field able to accommodate the inspected objects such as container trucks, the distance between the array detector and the accelerator target The distance should be ten meters apart. Therefore, this type of device requires a large building area and often requires a larger auxiliary area.

③ The accelerators used require special operation and operation personnel, and the repair and maintenance workload is very heavy and the price is high.

In actual work, a detection device with low radiation intensity, simple shielding, small footprint, less operating personnel, low price, and detection accuracy and scanning speed that can still meet the requirements is more needed. There are many needs, such as inspecting scattered containers or entire trains of railway wagons, etc., which are more difficult to be satisfied by this kind of accelerator-type detection device fixed in a heavy protective building.

The purpose of the present invention is to provide a mobile gamma digital radiation imaging non-destructive testing method and device and its function that can meet the actual needs and the whole device is easy to move and install.

Another object of the present invention is to provide a non-destructive testing method and device for gamma digital radiation imaging with low radiation intensity, simple shielding, and low price and its application.

The content of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic front view of the structure of the mobile γ-ray digital imaging non-destructive testing device of the present invention.

Fig. 2 is a schematic top view of the structure of the mobile γ-ray digital imaging non-destructive testing device of the present invention.

Fig. 3 is a schematic structural view of another embodiment of the detection device of the present invention.

Fig. 4 is a schematic diagram of the structure of a detection device in which the radiation source and the front collimator are located at a relatively high vertical position, without auxiliary support wheels, and the rear collimator and the array detector are double-disconnected.

Fig. 5 is a schematic diagram of the structure of the arc type rear collimator and the array detector.

Fig. 6 is a schematic diagram of the structure of the vertical rear collimator and the array detector.

Fig. 7 is a schematic diagram of a detection device for detecting a whole train of railway wagons.

Like parts in the figures are denoted by the same reference numerals.

The first aspect of the present invention relates to a mobile digital gamma radiation imaging non-destructive testing method. In this method, the detection device is arranged on a rigid frame, and a driving mechanism installed on or connected with the rigid frame drives the whole device to scan back and forth, or, the rigid frame is fixed, and the object to be inspected is moved from below it. Or dragged by the dragging mechanism connected with it, and scan forward and backward through the irradiation area in the rigid frame. At the same time, the collimated gamma-ray beam emitted by the gamma radiation source passes through the object to be inspected and is received by the array detector, thereby realizing the non-destructive inspection of the object to be inspected.

The gamma radiation source used in the above method is ⁶⁰ Co, ¹³⁷ Cs, ¹⁹² Ir and other high specific activity gamma radioactive isotope radiation sources.

The above-mentioned drive mechanism drives the rigid frame along the track to perform forward and backward translation and scanning motion relative to the object to be inspected according to the instruction, so as to complete the non-destructive inspection of the entire object to be inspected. The above-mentioned dragging mechanism drags the object to be inspected through the irradiation area in the rigid frame according to the instruction, so that it performs a forward and backward translational scanning movement relative to the rigid frame, thereby completing the nondestructive inspection of the entire object to be inspected. When a suspicious situation is found, the driving mechanism or the dragging mechanism can be slowed down and returned for review, so that further detailed inspection and judgment can be carried out.

The second aspect of the present invention relates to a mobile γ-radiation imaging non-destructive testing device.

Referring to Fig. 1, Fig. 2, detection device of the present invention is made of high specific activity gamma radiation source and its container 1, array detector 5, front collimator 2, rear collimator installed on the same movable rigid framework 3 It consists of a device 4, a signal and image processing unit 6, and a drive mechanism 7 installed on or connected to a rigid frame. 1# platform 10 and 2# platform 11 are respectively arranged on both sides of the rigid frame 3, the gamma radiation source and its container 1 and the front collimator 2 are arranged on the 1# platform 10, the rear collimator 4 and the array detector 5 , signal and image processing unit 6 and drive mechanism 7 are arranged on the 2# platform 11 on the other side, thereby forming a detection area. The object 8 to be inspected is set in the rigid frame 3 and placed on the rest table 9 . The following of 1# platform 10 is supported by auxiliary supporting wheels 12, and there are two rows of driving load-carrying wheels 13 below 2# platform 11. This load-carrying wheel 13 is arranged on the track 14, and can do forward and backward translational scanning motion along track. Drive mechanism 7 drives bearing wheel 13 by command, makes the rigid frame 3 that detection device is installed by track 14 by front and rear aspect (as shown by the arrow among Fig. 2) with certain speed to do translation scanning motion. The auxiliary support wheels 12 below the 1# platform 10 can assist to bear the weight of the gamma radiation source and its container 1 and the front collimator 2, which contributes to the stability of the movement of the frame-shaped rigid frame 3. Auxiliary support wheel 12 can needn't have track, and directly falls on flat ground and rolls.

Fig. 3 shows another embodiment of the detection device of the present invention. The object to be inspected 8 is arranged on the dragging mechanism 17, which is used to drag the object to be inspected to perform forward and backward translation and scanning motion relative to the detection device. Several height-adjustable support components 16 are provided below the 1# platform 10 and the 2# platform 11 for installing and fixing the entire detection device. The above-mentioned support member 16 may be a hydraulic mechanism, a mechanical lifting mechanism or the like. The dragging mechanism 17 can drag the object under inspection relative to the detection device to perform forward and backward translation and scanning motions at a certain speed according to instructions.

The gamma radiation source adopts high specific activity ⁶⁰ Co, ¹³⁷ Cs, ¹⁹² Ir and other gamma radioactive isotope radiation sources, the active area is several millimeters in size, and the activity ranges from a few Curies to hundreds of Curies (1×10 ¹¹ ~3×1C ¹³ Bq). For large inspected objects such as containers, ^{a 60} Co radiation source with high gamma ray energy should be selected. For objects with a smaller mass and thickness, a radioisotope radiation source with lower gamma ray energy can be selected. The specific activity and activity range of the gamma radioactive isotope radiation source used in the present invention are basically consistent with those of the gamma radiation source for industrial flaw detection, and the latter has been supplied with a large number of finalized products. The detection device of the present invention can adopt such an industrial flaw detection gamma source with its own shielding container, thereby increasing the reliability of the operation of the whole device and significantly reducing the cost.

The front collimator 2 is made of metals such as lead and iron or their alloys, and is closely matched with the gamma radiation source container. The collimating slit in the middle of the front collimator collimates the γ-rays emitted by the radiation source into a sheet-shaped ray beam with a horizontal angle of 0.1° to 1° and a vertical angle of tens of degrees.

The rigid frame 3 is a frame structure, which is a rigid frame for connecting and installing each unit in the detection device. The frame-shaped rigid frame 3 must have sufficient strength and rigidity to ensure that the relative positions of the radiation source and its container 1, collimators 2 and 4, array detector 5 and other units are fixed. The span and height of the frame-shaped rigid frame 3 should be determined by the vertical angle of the irradiation field of the radiation source, the position and size of the object to be inspected, and the distance between the radiation source and the array detector 5, and must be able to Move across the entire subject without hindrance. As long as the strength and rigidity of the frame-shaped rigid frame 3 are large enough, the auxiliary supporting wheels 12 can be eliminated.

The rear collimator 4 is also made of metals such as lead and iron and their alloys. It is firmly installed on the frame-shaped rigid frame, the width of the collimation slit in the middle is equal to or slightly larger than the pixel width of the array detector 5, and it is strictly aligned with the collimation slit of the front collimator 2 and the radiation source active area. In order to make the distance difference between each detector element and the gamma radiation source small, the rear collimator 4 should be in the shape of a single zigzag line as shown in Figure 1, wherein the length of the upright part is basically the same as the height of the object to be inspected.

When the vertical position of the 1# platform 10 is different, the shape of the rear collimator 4 should also be changed accordingly, but the geometric center of the active area of the radiation source should be kept basically.

In some cases, the position of the radiation source needs to be raised. In order to make the sheet-like beams containing the object under inspection all be received by the array detectors, and at the same time make the distance difference between each detector element and the radiation source small, the rear collimator 4 is specially designed as a bifold line, wherein the upright part The length is basically the same as the height of the tested object. As shown in FIG. 4 , the height adjustment mechanism 15 in the figure can be used to adjust the vertical height of the 1# platform 10 . The rear collimator 4 can also be designed in an arc shape, as shown in FIG. 5 . Another embodiment of the rear collimator 4 is an upright structure, as shown in FIG. 6 . The arc-shaped rear collimator helps to improve the detection conditions, but it will increase the difficulty and cost in processing.

The array detector 5 is generally composed of a plurality of detection units including a certain number of detector elements arranged in sequence. Each detection unit should be aimed at the active area of the gamma radiation source, and fixed on the rigid frame 3 respectively. The detection blind area between each detection unit must be smaller than the height of one detector element pixel, so as to avoid the loss of information and obtain a good gamma radiation projection image. The rigid frame 3 and related installation and fixing measures must ensure that each detector unit, front and rear collimators and active areas of the radiation source are aligned with each other. The gamma rays emitted by the radiation source 1 should be collimated into a sheet-like beam by the front collimator 2, and then pass through the rear collimator 4 and accurately enter the sensitive volume of each detector element of the array detector 5. . The total number of detector elements is such that the total sensitive volume of the array detector 5 can match the gamma radiation irradiation field containing the inspected object 8 .

The function of the array detector 5 is to convert the γ-rays injected into its sensitive volume after passing through the object to be inspected into electrical signals, and then feed them into the following electrical signal and image processing unit. It is required to have high detection efficiency and charge sensitivity, be stable and reliable, and be able to withstand vibration and poor environmental conditions during scanning. There are many kinds of array detectors that can meet these requirements, such as "gas ionization type high-energy x, gamma radiation imaging array detection device" described in Chinese patent ZL93102728.4, proportional chamber, proportional tube or Geiger tube array, scintillation detector array or semiconductor detector array, etc.

The electrical signal and image processing unit 6 includes all analog processing circuits such as the front-end circuit for receiving and amplifying the output signal of the detector, an analog-to-digital conversion (ADC) circuit, some or all digital circuits and a computer. Operators and computers can be placed on the 2# platform 11 at the same time, move together with the rigid frame 3, detect the internal situation of the object in real time, and take corresponding measures in time, or they can be placed at an appropriate position at a certain distance to complete the same works but does not move with the rigid frame 3. In the former case, necessary operator protection facilities, such as lead and iron barriers, should be set up on the 2# platform 11.

In order to make the rigid frame 3 move smoothly, and to adapt to the situation of canceling the auxiliary supporting wheels 12, the center of gravity of each unit of the entire rigid frame together with the detection device installed thereon should fall between the two rows of driving load-carrying wheels 13. For this reason, can add some weights on 2# platform 11 and use as counterweight body if necessary. The counterweight can also be designed as a protective barrier for the operator.

The driving device 7 installed on or connected to the 2# platform 11 of the rigid frame 3 includes a motor with sufficient power, an internal combustion engine or other power machinery, and a control mechanism and a transmission mechanism. It can make the rigid frame 3, together with the detection device installed on it, scan forward and backward along the track at a certain speed according to instructions.

Track 14 is laid on flat ground, can guarantee that the rigid frame 3 that rolls forward moves steadily on it, and vibration is little.

The rest table 9 is used for resting the object 8 to be inspected that is stationary during the inspection. It can be a simple bench structure, and it is convenient to place or remove the object to be checked. It can also be attached with a set of transmission mechanism for conveying the object 8 to be inspected, but the function of this transmission mechanism is only to place or remove the object to be inspected, and it does not act during the inspection process, and there is no requirement for speed and speed stability. is simple.

The object 8 to be inspected may be a large object or a small object. A large object refers to a container, a container truck, a train car, a missile or even a whole train. What Fig. 7 shows is the situation when the checked object is the whole train. Among the figure, the checked train is stationary, which is completed by the train braking device without shelving the platform 9 . During detection, the drive mechanism 7 drives the detection device as a whole to perform forward and backward translational scanning motions relative to the train along the track 14 . Small objects refer to crankshafts, cylinder blocks, fins, castings, forgings, machine parts, explosives and their parts, or pressure vessels and their parts.

When the object to be inspected is a large object, the object to be inspected is stationary, and the whole detection device performs forward and backward translational scanning motion relative to the object to be inspected, as shown in Fig. 1 , Fig. 2 and Fig. 7 . When the object to be inspected is a small object or easy to drag, the detection device can be fixed, and the object to be inspected is dragged by the drag mechanism 17 to pass through the irradiation field in the rigid frame 3 for forward and backward translational scanning movement, as shown in Figure 3 .

The third aspect of the present invention relates to the use of the mobile γ-ray digital imaging non-destructive testing device. The device can be used to detect both large and small objects. The device is installed in customs land border ports, ports, airports, traffic arteries, railways and other places to detect the internal conditions of large objects such as containers, container trucks, train carriages, trucks and even entire trains, and to find smuggling, prohibited, dangerous, etc. , The case of incorrectly shipped items. The device can also be installed in the assembly site of missiles and large rockets, etc., to detect the internal conditions of large objects such as missiles and large rockets, and to identify abnormal phenomena such as assembly errors.

The detection device of the present invention can also be applied to the field of industrial non-destructive testing where the object is small in size and requires high detection accuracy, for detecting crankshafts, cylinder blocks, fins, castings, forgings, machine parts, pyrotechnics and parts thereof, Internal conditions of small objects such as pressure vessels and their parts, so as to check and find defects such as shrinkage cavities, slag inclusions, and cracks inside. Continuous online non-destructive testing can be performed on the production line.

The working process of the detection device of the present invention is as follows:

The gamma rays emitted by the gamma radiation source are collimated by the front collimator 2 into a sheet-like beam and then pass through the object 8 to be inspected, and then collimated by the rear collimator 4 and then enter each detector element of the array detector 5 Sensitive volume. The output signal of each detector element is proportional to the intensity of the gamma rays received at its position, and the intensity of the gamma rays is related to the absorption capacity (ie mass thickness) of the corresponding part of the object 8 passing through the ray travel path. Collect and process the output signals of each detector unit acquired within one sampling time, arrange and display them in sequence, and obtain a layer of object in a vertical direction reflected by the sheet-like ray beam passing through on the computer screen. Image scan lines of mass distribution in the body. With the relative translational scanning motion between the detection device and the object to be inspected, the sheet gamma ray beam will scan the various parts of the object to be inspected layer by layer according to the direction of the scanning motion, reflecting the "diagrams" of the internal mass distribution of the object. The "image scanning lines" will be displayed sequentially, and finally a two-dimensional γ-ray digital radiation projection image of the object to be inspected will be obtained. Using various computer image processing techniques, the image can be zoomed in with local windows, adjusted in gray scale windows and false color windows, etc., so as to observe the details of different levels of the image, and record, archive or output the test results.

In the detection device of the present invention, the object 8 to be inspected is generally stationary during the scanning detection process, and the detection device installed on the rigid frame 3 makes a scanning movement along the track 14 . At this time, the relative motion speed between the object 8 to be inspected and the detection device is completely determined by the drive mechanism 7 on (or connected to) the rigid frame 3 according to the received instructions. According to the radiation statistical fluctuation theory, under the same radiation source activity and other conditions, the slower the scanning motion, the smaller the statistical fluctuation of the collected data, and thus the clearer the obtained gamma digital radiation projection image. In the process of inspecting the object 8 at the conventional scanning speed, if any suspicious points are found, the detection device can be slowed down and re-scanned at suspicious parts to achieve finer detection.

After the entire detection process of a detected object 8 is completed, the object that was stationary during the detection is removed, and a new detected object is replaced to carry out the next round of scanning detection process. Repeatedly, the detection can be continued continuously.

In the case of a very long and large object to be inspected, such as a whole train of railway wagons, the detection device of the present invention will move on the parallel rails arranged beside the train, and can continuously scan and detect the whole train of wagons. The obtained gamma digital radiation projection images of each carriage can be discriminated and processed in time, and can also be stored and then observed, or transmitted to a certain inspection center for unified observation and processing.

In some cases, such as the object to be inspected is small or easy to drag, the rigid frame 3 and the detection system on it can be fixed in a certain position by its supporting parts, so that the object to be inspected is pressed by a certain amount during detection. The speed requires movement (as shown in Figure 3), and the gamma digital radiation projection image of the object to be inspected can also be obtained.

The "mobile type" of the mobile γ-radiation imaging non-destructive testing device of the present invention is not only represented by the scanning movement of the detection system during the detection process, but also in the fact that the entire detection device is easy to carry and move to the required place for operation. Because the detection device is only required to be laid on the ground track 14, shelving table 9, auxiliary support wheel 12 required flat ground and general protective measures etc. to the requirement of supporting conditions, and the weight of the whole detection device is no more than several tons, so this This kind of handling and movement between different locations according to needs is possible and easy to realize.

When all electrical signal and image processing units 6 and operators are placed on the 2# platform 11, all detection, signal processing and judgment processes are realized and completed on the rigid frame 3. When the operator and the image display and processing computer etc. are not placed on the 2# platform 11, they will be placed in the monitoring room at the proper position, which can make the operator and the computer have a better working environment.

Example:

The embodiment of the present invention is a mobile γ-ray digital imaging non-destructive testing device mainly used for testing containers or container wagons

This device uses a high specific activity ⁶⁰ Co radiation source with an activity of hundreds of Curies (less than 2×10 ¹³ Bq), the horizontal angle of the collimated ray beam is 1° smaller, and the vertical angle is about 60° . The front collimator is made of lead and the rear collimator is made of iron. The array detector described in Chinese patent ZL93102728.4 is selected. It adopts the front-end circuit of DC working mode and the analog-to-digital conversion circuit with precision above 12bit. Signal and image processing is performed by a high-end microcomputer. The scanning speed of its rigid frame is 10-30 cm/s. The detection performance index achieved by this embodiment will be: the density contrast sensitivity (CI value) to 100 millimeters of iron screen absorbers will be better than 1.5%, and the image quality index (IQI value) under the same absorber condition will be 3 ~4.5%; penetration power (SP value) can reach 200mm iron. This has been able to meet the needs of the customs investigation work quite well. The above indicators will be further improved by choosing a larger value in the activity range of the given radiation source. The CI value can be less than 1%, the IQI value will be less than 3%, and the scanning detection speed can reach 30 cm/s.

The features of the present invention are:

① The industrial gamma flaw detection source used is originally designed and manufactured for industrial field application, and the protective performance of the shielded container can ensure that it can operate safely in the open field. Therefore, the detection device of the present invention does not need a heavy protective building, is easy to ensure radiation safety, and can also operate in an open field with a certain warning range.

②A different detection mode is adopted in which the detection system performs scanning motion while the object to be inspected is stationary, which is especially beneficial to the non-destructive inspection of the object to be inspected that is heavy, long, large, and inconvenient to drag. This can save the huge and complex driving maneuvers that require a certain moving speed and speed accuracy, with a load of more than tens of tons. This will significantly reduce the cost of the detection device and increase the degree of reliability.

③The weight of the entire detection device is only a few tons, and the required external conditions are mainly facilities that are easy to implement such as tracks and flat ground, so it can be easily transported, transferred, and placed to the required location for operation without having to put all The test objects are all transported to a fixed location where the test device is located. This is very beneficial for places where container stacking is scattered such as ports.

④ Since there is no need for a heavy radiation protection building and a huge dragging device, this will significantly reduce the required building area and the auxiliary site to be occupied.

5. Because the gamma radioactive isotope radiation source which is light in weight, small in size and basically does not require maintenance is used to replace the accelerator which is expensive and needs to be equipped with a special operation and maintenance team, the price of the detection device of the present invention and the required The number of operation and maintenance personnel.

In summary, it can be seen that the detection device of the present invention will be a mobile non-destructive detection device for gamma radiation imaging with simple shielding, reliable operation, low price and easy operation. Its price will be only a fraction, or even a tenth, of that of an accelerator-type detection device. This is very beneficial to popularize the application.

Claims (18)

1. A gamma digital radiation imaging non-destructive testing method is characterized in that the detection device is arranged on a rigid frame, and a drive mechanism mounted on the rigid frame or connected to it drives the whole device to do forward and backward translational scanning motions, or, The rigid frame is fixed, and the dragging mechanism under or connected to the object under inspection drags the object under inspection through the irradiation area for forward and backward translational scanning movement. At the same time, the collimated γ-ray beam emitted by the γ radiation source After passing through the inspected object, it is received by the array detector, so as to realize the non-destructive inspection of the inspected object. 2. The method according to claim 1, characterized in that the radiation source is ⁶⁰ Co, ¹³⁷ Cs, or ¹⁹² Ir high specific activity gamma radioactive isotope radiation source. 3. The method according to claim 1, characterized in that the above-mentioned driving mechanism and dragging mechanism drive the rigid frame or drag the object under inspection to perform forward and backward translational scanning motions according to instructions. 4. A mobile non-destructive testing device for digital γ radiation imaging, comprising a γ radiation source and its container, a front collimator, a rear collimator, an array detector, an electrical signal and image processing unit, and a dragging mechanism. It is characterized in that the device also includes a rigid frame and its driving mechanism, the gamma radiation source and its container, the front collimator, the rear collimator, the array detector, the electrical signal and image processing unit and the driving mechanism are fixedly installed on the same rigid frame , and the gamma radiation source and its container, the front collimator, rear collimator, array detector and its electrical signal and image processing unit are respectively set on the 1# platform and 2# platform on the opposite sides of the rigid frame, to form a detection zone. 5. The apparatus of claim 4, wherein said radiation source is a high specific activity gamma radioisotope source. 6. The device according to claims 4 and 5, characterized in that said radiation source is ⁶⁰ Co, ¹³⁷ Cs, or ¹⁹² Ir. 7. The device according to claim 4, characterized in that said front collimator and rear collimator are made of lead, iron or alloys thereof. 8. The device according to claim 4, wherein the array detector is an array ionization chamber, a proportional chamber, a proportional tube or a Geiger tube array, a scintillation detector array or a semiconductor detector array, and a plurality of detectors comprising a certain number The detection units of the device are arranged in sequence. 9. The device according to claim 4, characterized in that the rear collimator is in the shape of a straight line, a single zigzag line, a double zigzag line or an arc, and the array detector must be matched with the above-mentioned rear collimator. 10. The device according to claim 4, characterized in that auxiliary support wheels are provided under the 1# platform, and load-bearing driving wheels are provided under the 2# platform. 11. The device according to claim 4, characterized in that there are also supporting parts fixedly supporting the entire rigid frame under the 1# platform and 2# platform. 12. The device according to claim 4, characterized in that a part of the electrical signal and image processing unit is fixedly installed on the rigid frame, and the rest is arranged at a proper position with a certain distance from the rigid frame. 13. The device according to claim 4, characterized in that the driving mechanism drives the entire rigid frame to perform forward and backward translational scanning movement relative to the object under inspection according to the instruction, and the drag mechanism drags the object under inspection through the rigid frame according to the instruction. The irradiated area performs a forward and backward translational scanning movement. 14. The device according to claim 4, characterized in that the span and height of the rigid framework should be greater than the width and height of the object to be inspected. 15. The device according to claim 4, characterized in that a height adjustment component is arranged on the rigid frame to adjust the vertical height of the 1# platform. 16. The use of a γ-ray digital imaging non-destructive testing device, characterized in that the device is used to perform γ-radiation digital imaging non-destructive testing on large objects or small objects. 17. The use according to claim 16, characterized in that the above-mentioned large object is a container, a container truck, a train car, a truck, a missile or a whole train. 18. The use according to claim 16, characterized in that the above-mentioned small objects are crankshafts, cylinder blocks, fins, castings, forgings, machine parts, explosives and parts thereof, or pressure vessels and parts thereof.

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