RADIOISOTOPES

To sterilize the bacteria on the surface of the woodblocks, low energy X-rays of 150 kV were used to irradiate them without using filters, which was six times faster than general X-ray irradiation methods. Insect damage to the woodblocks could be distinguished from cracks and physical destruction only by visual inspection and simple X-ray radiography. These techniques were manualized and transferred to Vietnam. At that time, 0.5 mGy of X-rays irradiated within the baggage inspection and 9 µSv of cosmic radiation of travel routes had no effect on the film dosimeter and X-ray film.