Condition for use:It is forbidden to the OPERATORS TO TRESPASS the recommend safety distance while the source shutter is opened.A special red-and-green signal light assembly indicates if the beam is active (when the shutter is open, the signal lamp is on).When the beam is not working (shutter closed and green lamp on) the operator is subject only to runaway radiation.No adjustment to be carried out within the recommend safety distance is needed to operate the system.