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Abstract: In radiographic flaw detection work, under complex on-site conditions, no matter how the focal length of the transillumination changes, or how the specifications of the workpiece to be penetrated change, it can accurately provide exposure parameters. Use the standardized exposure parameters to expose the film, and all the films obtained in this work will have the same or similar blackness value, and comply with* * Relevant provisions in professional standards. Keywords: New instrument radiographic flaw detection exposure parameters With the continuous improvement of my country's productivity, the application of non-destructive testing is becoming more and more common. Radiographic testing has always attracted much attention because of its unique advantages. As a grassroots worker in radiographic flaw detection, how to do radiographic work well so that this working method can reflect the value of its application and play its role in practical work is the focus of our work. In our actual work, on-site work occupies a large proportion. Friends who have been engaged in radiographic flaw detection all know that because the radiographic machine factory provides us with an exposure curve with a fixed focal length of 600mm or 500mm, and under the complex conditions of the site, it is impossible to fully meet the requirements given to us by the radiographic machine factory. In this case, our work experience often plays a big role. According to the situation at that time, adjust the tube voltage and exposure time appropriately to meet the requirements of the film exposure. However, for comrades who are not very experienced in work, this is a very difficult problem. The choice of exposure is particularly difficult and important. Once the exposure is not appropriate, at least during the process of developing the film, you can only rely on sacrificing the development time in exchange for the blackness of the film to ensure the film evaluation effect. This is * * It is strictly forbidden to use it in professional standards. In serious cases, the exposure may be too large or too small, causing the blackness of the film to be too large or too small, which cannot meet the requirements of the film review. This makes the filming work in vain. Since the filming work is mostly done at night, it will be doubly hard. Once the filming work fails, you can imagine how you feel. We know that under complex site conditions, the distance between the radiograph machine and the transmitted workpiece (that is, the transillumination focal length) changes at any time according to the site conditions. Sometimes the distance is more than 800mm. Sometimes it can only be around 300mm. The specifications of the transmitted workpiece often change with the site conditions. Take a power plant as an example. The most common detection parts in a power plant are The boiler has four small tubes, namely: water-cooled wall Φ60x6mm, superheater Φ42x5.5mm, economizer Φ38x4mm, reheater Φ42x3.5mm, and many other specifications. The specifications of the workpiece to be inspected are changing all the time. The distance between the X-ray machine and the workpiece is also determined according to the conditions on site. In this case, the role of the exposure curve provided to us by the manufacturer * * has been reduced. Instead, our work experience often plays a greater role. In this case, the exposure selected must not only meet the conditions of film development time and temperature, but also make the blackness value of the film meet * * Requirements in professional standards. This is a relatively difficult thing for comrades with relatively little work experience. In order to standardize the exposure parameters of the film at work, and then obtain the appropriate film blackness according to the standardized exposure parameters, and get rid of the method of relying solely on work experience, so I used more than ten years of work and combined with my own accumulation. More importantly, to meet the needs of actual on-site work, I developed a practical instrument: a radiographic flaw detection exposure parameter meter. The characteristic of this instrument is that no matter how the transillumination focal length changes or the specifications of the transilluminated workpiece change, you only need to enter the transillumination focal length of the current working condition and the thickness of the transilluminated workpiece. After confirmation, you can get the exposure voltage and exposure time that are suitable for the current situation. If you use the exposure parameters provided by the instrument for exposure, you can make the film meet the development time of 5 minutes and the development temperature of 20°. At the same time, all the films obtained in this work have the same or similar blackness value and meet the requirements. * * The blackness range required in professional standards. Currently, this instrument has obtained * * The patent has also been recognized by the Tianjin Boiler and Pressure Vessel Inspection Center, proving that it can play a certain auxiliary role in work under complex on-site conditions. It has also been affirmed by several other specific users. The characteristics of this instrument: According to the actual working conditions at the time, enter the focal length and specifications of the exposed workpiece. After confirmation, you can get the suitable tube voltage and exposure time for the current situation. We recommend high voltage and short time, but the time is greater than or equal to 1 minute. At the same time, in order to solve the problem of milliamp requirements in industry standards, after obtaining the tube voltage and exposure time, you can also modify the given tube voltage (lower the tube voltage). After confirmation, you can get the modified tube voltage and the corresponding new (slightly longer) exposure time. But the modified tube voltage must be able to meet the ability to penetrate the wall thickness of the workpiece. In addition, this instrument also has tube and plate options. Among them, the tube material selection This item refers specifically to tubes suitable for the double-walled double-projection transillumination method. Other transillumination methods are suitable for our plate options. Friends who are engaged in radiographic flaw detection all know that in the transillumination method for small-diameter tubes. The industry standard of the People's Republic of China JB/T4730.2 Ray Chapter stipulates that "the tube diameter is 0.03. The thickness of the front and rear screens of the intensifying screen is in accordance with industry standards. Use new developers, etc. These external factors can be ignored. In the latest by * * The Industrial Standard JB/T4730.2 Rays of the People's Republic of China was promulgated by the Reform and Reform Commission in July 2005 and officially implemented in November 2005. Section 4.11.2 has clear requirements for the blackness of the film, namely 1.5