The function of the portable x ray collimator is to control the X-ray irradiation field, so that the X-rays required for human diagnosis can be controlled within a certain range and position, thereby avoiding excessive X-ray damage to the human body, so the quality of the portable x ray collimator is ensured. , we have to do, what is the specific standard? In the industry standard YY0007 ~ 0009-90 on the technical standard of 200 ~ 500m medical diagnostic X-ray machine, the performance requirements of the portable x ray collimator in Article 4.19 are as follows: the portable x ray collimator should be light, flexible, reliable, and It can adjust the rectangular illumination field of any size. When the gastrointestinal examination photographic device is pulled farthest from the bed surface and the beam limiter is closed to a minimum, the illumination field on the screen should be no more than 20 mm20. The deviation of the center of the X-ray irradiation field from the center of the light irradiation field and the deviation of each edge thereof should be within 2% of the distance from the focus of the X-ray tube to the image receiving surface.