"Radioisotope and radiation device safety and protection regulations" according to the degree of potential harm to human health and the environment of radioactive sources, radiation devices, from high to low is divided into Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ;
A class of devices such as direct plus, etc.
Two types of devices, such as the DSA
Three types are dr and so on
.