X-ray safety inspection instrument radiation problems need to measure security

Introduction: Not long ago, the media reported on the "radio leakage problem of subway security inspection machines." In response, Yang Yong, one of the main drafters of China's "X-ray safety inspection instrument calibration standards," was widely used in stations, ports and airports throughout China. X-ray safety inspection devices (commonly known as security inspection machines) in places such as subways and subways have conducted detailed studies.

On Monday, November 7th, at 8 am, the crowds at Beijing Sihuidong Subway Station surged. The morning peak on Monday is often the time when the subway interchange station is under the most pressure. After passing through the security inspection machine at the entrance, Wang ** deliberately bypassed the staff and opened the bag he carried with him, taking the initiative to let the security personnel carry out a manual inspection. “There was a lot of media coverage on the safety of subway security machines in the media some time ago. Regardless of whether it is really dangerous, I still try to stay a bit farther away from the security machine for the baby in my stomach.” Wang ** Pregnancy for more than 6 months, the subway It is the transportation that she must take every day to and from work, and every time the security inspection machine at the entrance to the subway always makes her worry.

Yang Yong, a radiation research institute of the China Institute of Testing Technology, recently paid close attention to the radiation safety of subway security inspection machines. As one of the main drafters of China's "X-ray Safety Inspection Instrument Calibration Specification", Yang Yong has conducted detailed X-ray safety inspection instruments (commonly known as security inspection machines) widely used in stations, ports, airports, subways and other places across China. the study. Regarding the media leakage problem of subway security inspections recently, Yang Yong has his own opinion: “Because of the special nature of the application site, a large number of X-ray security inspection equipment will be used uninterruptedly and even 24 hours of uninterrupted operation. If there is a problem with the lead curtain of the X-ray safety inspection device, or if it is damaged, it will cause excessive radiation leakage. In addition, if the machine is used for a long time, if the internal device is repaired or changed, the performance of the device may be changed. Caused the leakage of radiation." But Yang Yong also said: "We have done a lot of follow-up experiments. So far, no radiation dose leakage has been detected. In general, X-ray security inspection instrument still shows a good security situation. "Because there is a possibility of radiation leakage exceeding the standard, Yang Yong suggested from the perspective of radiation measurement: "X-ray safety inspection equipment should conduct a performance test once a year, including the detection of radiation leakage indicators."

The annual inspection of the X-ray safety inspection instrument is also recommended by Tang Weidong of the ionization radiation room of the Shanghai Institute of Metrology and Measurement Technology. The Shanghai Institute of Metrology and Measurement Technology is an organization that has conducted X-ray security inspections earlier in the country. Regarding the radiation safety of security inspection machines, Tang Weidong holds similar views with Yang Yong. He said: "The long-term frequent use may cause changes in the technical performance of the X-ray baggage screening device's ray device, which results in the weakening of the article's ability to see through the security device, the reduced resolution and clarity of the image, and potentially causing misjudgments and omissions. On the other hand, if the security of the security inspection machine is not properly maintained, some people will be damaged or will be in disrepair over a long period of time, and it is likely that the protection of the X-ray leakage rays will not reach the factory's performance. This will give relevant personnel who use X-ray security inspection instruments all year round. The health and safety of the public brings about hidden troubles, especially when the lead plastic curtains of luggage entering or exiting are prone to damage due to breakage, the risk of radiation is greater.” Therefore, Tang Weidong believes that the X-ray baggage security instrument is regularly calibrated. Testing is very necessary.

According to reports, X-ray baggage security instrument is a comprehensive application of X-ray penetration of the characteristics of the object, the principle of interaction between photons and matter, ray detection and imaging technology, image processing technology for item detection. X-ray baggage screening equipment is currently one of the most effective safety inspection methods and is widely used in stations, ports, airports, subways and other places throughout China. During the Beijing Olympics and the 2010 Shanghai World Expo, X-ray security equipment has played an irreplaceable role.

In order to ensure the accuracy and reliability of the X-ray baggage inspection instrument and ensure public safety, the National Ionizing Radiation Measurement Technical Committee has drafted the "X-ray Safety Inspection Instrument Calibration Standard" and it has been implemented since April of this year. The specification specifies the metrological characteristics of the X-ray security tester in terms of its resolution, penetrating power, material resolution, and leakage radiation. At the same time, Shanghai Metrology and Testing Technology Research Institute successfully established a calibration device for X-ray security inspection equipment by conducting research on the type, design principle and technical performance of X-ray baggage screening machines and a large number of field tests.

In the industry evaluation, the preparation of the "X-ray safety inspection instrument calibration specification" and the development of X-ray safety inspection equipment calibration equipment provide technical basis and standard equipment for the calibration work of China's baggage safety inspection instrument project, which fills the security of our country's transportation package. The blank of the calibration of the detector is conducive to improving the quality of security services such as customs, trade ports and airports in China.

“With the technical support of relevant specifications and calibration equipment, the metrology verification department can better perform professional performance inspections of the security inspection machine from the point of view of radiation measurement.” Tang Weidong showed strong confidence in this, but at the same time he also felt It is full of worries: “This specification is not mandatory, and whether it can successfully implement regular inspections of the radiation measurement performance of the security inspection machine will also require the thorough cooperation and effective communication of relevant departments and enterprises, and these efforts will be far more effective than relying on a single specification. fixed."