摘要：In measuring the amount of x-ray radiation through mass x-ray examination cars in O-city, two pieces of equipment giving of a high level of radiation were found in seven cars, the amount of each differing remarkably from the others. However, it was found that through improvement (of the quality) of the equipment, the amount of the radiation could be reduced to some extent. For instance, changing the fluoroscope resulted in a radiation reduction of 25% and a 36% reduction when supplemented by a filter. It was also found that voltage selection of the x-ray tube was important for achieving a reduction.
