For systems having energies of 1 MeV or more, the permittee shall obtain from the manufacturer or determine, with reference to an accessible point on the radiation head, the location of:

1. (1) the x-ray target or the virtual source of x-rays; and
2. (2) the electron window or the virtual source of electrons if the system has electron beam capabilities.

Added at 17 Ok Reg 1136, eff 6-1-00