부산대학교 도서관

From a practical angle of view to estimate the protection factors (PFs) provided by full-face masks, a number of protection factors were measured with a man-test apparatus just before the wearers started to do radiation work in radiation controlled area. PFs of the total number of 2, 279 cases were measured under five simulated working conditions. The measured PFs were widely distributed from 2.3 to 6, 700. About 95% of workers obtained PFs more than 50, and about 64% showed much higher PFs more than 1, 000 due to good fitting. In the case of some persons, the measured PFs irregularly varied and changed to a large degree. This method is a reliable technique that has been confirmed to protect unexpected internal exposure. From the results obtained, the method should be necessary to provide a better mask and higher PF for each worker.